What is the best longboarding for you?

A new longboard is often an extended variation of a skateboard which in turn throughout mother nature is often a sports medium and is also used by travelling, hanging around, downhill sporting along with slalom sporting. The idea has a patio that is created from timber cedar plank, bamboo bed sheets as well as fiberglass product and possesses wheels, pickup trucks, bushings, footpads, bearings, insane along with screws. Let’s please take an experience when camping little by little after which it improve to find out precisely what longboards you might need no matter whether you happen to be a new rookie or possibly a specialized skater.

Longboard as being a Travelling Channel:

Longboard is often a balanced along with ecological warm and friendly medium involving journeying along with travelling. Competitors preserve his or her longboards in several styles, forms along with patterns along with customizing their skateboards as outlined by his or her requires. Longboards are generally totally free of just about any site visitor’s troubles, place difficulties which enable it to always be quickly sent derived from one of aspot for a yet another. Longboard companies preserve touching newcomers and also qualified skaters ahead of making just about any brand-new product or service. Today’s longboards are generally a consequence of serious analysis along with ongoing advancement inside shapes and forms involving longboards good require involving skaters.

Do you know The best Longboard Brands for you?

Seeking the best longboard along with deciding on your best longboard brands might be hard should you be simply a rookie. Consult a lot of competitors along with anyone gives you some other reply, a number of replies will certainly meet anyone and some may possibly mix up anyone along with towards the end in the morning you can visit a new finish there’re zero certain replies throughout deciding on your best longboard. Medication using just about any sport your current capability commences via actually zero if anyone train regularly your chart of your respective expertise commences increasing day-to-day and also an occasion occurs if you turn into trained in within it. You could be experienced in one particular sport along with most likely are not that will pro in any various other sport since you possibly will not always be suitable for that will sport, very same is valid using Longboards, don’t assume all are generally well suited for everyone potential. Mastering a skill along with turning out to be an authority within it, in addition, is determined by your current aspiration.

best longboard for travelling

Using Longboards for Carving:

Carving is often a technique that permits a new reader command the rate on a trip downhill. An idea is an efficient approach to command your current take a trip thereby snowboards for the purpose of carving merely are generally encouraged. Normally concave snowboards are widely-used pertaining to carving uses given that they help out with switching weight suitably down the aboard if you low fat your current longboard to show as well as theend, additionally, they help out with having entire benefit from your current carving knowledge. Underneath are our encouraged brands involving longboards pertaining to carving.

Longboards for traveling:

Longboards pertaining to hanging around may be completely different from standard skateboards, these are generated for prolonged excursions, sharpened spins along with hard roadways. Normally prolonged period snowboards are widely-used pertaining to cruising, his or her pickup trucks along with wheels are generally decided on specially to compliment these people pertaining to greater transforming along with easy flights. Currently small period along with tiny cruisers similar to 80’s retro-styled snowboards are accepted when they are easily lightweight, tough which enable it to be put in a very hard drive locker quickly. Underneath are your longboards involving our alternative.

Finally,Longboards appear in distinct types beginning from rookie knowledge similar to finding out how to stay with anaboard for you to pro knowledge similar to moving as well as bouncing or maybe undertaking the best longboard brands. Thinking of your current expertise quantities along with that may help you, We’ve built eight types along with allocated a new aesthetic data for you to every single classification, by simply under-going this kind of maps you’ll be able to pick a qualified product or service as outlined by your current knowledge quickly.

Why Meat Grinders are good for health?

Meat Grinders give you the chef a fantastic method to prepare a health meal. A best meat grinder will be user-friendly and also an easy task to clear. They may be sanitary regarding continuous utilize and also re-use. That is a significant section of an individual’s tiny kitchen devices. Any Meat Grinder is a wonderful solution to handle excess fat articles. They will help make meats better to break down and also acquire only some minutes to be able to grind any single pound or perhaps a couple of regarding meats. That is if you utilize any handbook grinder the best impact. Several are produced from Metal Steel. Equally can be sanitary to utilize. Folks notify me in which at times washing can be a job.

Is meat grinder avoiding germs?

The particular chemical p includes with all the metallic creating that to turn dim. One more illustration regarding reasonable to search with a top quality web site in which price and also reduced rates are usually pressured Prior to being able to get close to the specific grinding with the meat, I would recommend while using the FDA recommendations on washing meats, fruits, greens, and also almost all generate. This consists of cleansing the hands no less than twenty (20) seconds together with soap and also water, rinsing the particular meat or perhaps generate for a number of minutes. And also, just before going forward more it is crucial to scrub the palm once more together with soap and also water to cut back and also eliminate the best impact exchange regarding bacteria from your meat and generate returning to the hands prior to deciding to keep on foods preparation.

Why is it good for health?

  • It’s also advisable to modify the particular cutting table and also virtually any plate or perhaps dinners found in organizing meats in addition to all the food items.
  • Whether or not you employ any blade or even a slicer, you have the identical final results. A tad bit more utilize a blade, nevertheless the identical final results none-the-less.
  • Be sure you rinse palms just before and also right after when working with diverse equipment and also devices regarding foods preparation.
  • Hold the Meat inside tiny bits cut simply by 2×2 or perhaps 1×2 inch parts help make the particular grinder perform a smaller amount.
  • This kind of keeps the particular generator of your Electronic Meat Grinder plus your palms and also biceps and triceps to get a Manual Meat,
  • Try out the particular training course, method and also great grates available about several grinders marketed nowadays. You’ll find they can offer a lot more selections for imaginative foods preparation as well as the food preparation in which uses.
  • I am aware folks have got certain dishes at heart before you begin this technique as well as other in which just like the flexibility regarding continuous and also steady imagination any time food preparation following your achievement regarding foods preparation.
  • This is equally a very important thing and also irritating according to your own personal tastes. I do believe the most effective and also healthiest metallic to utilize will be Metal Steel.
  • Washing now is easier typically and also Metal Steel will be resilient also. Bacteria’s hate precious metals. Whilst it can easily go on these, they cannot locate metallic foods preparation goods as being since ‘inviting areas to call home.
  • Steer clear of everything you can easily in order to avoid lowering options regarding healthier foods preparation.
  • Bacteria’s, not necessarily finding the time to be able to appropriately get ready meats as well as other food items before you begin to be able to make will be the wise practice section of this informative article.

Finally, do not let a moment or perhaps not enough moment result in issues inside the kitchen. Acquire delight within your health. Acquire enjoyment inside all you take in. Ensure you order this kind of in order to avoid regrets best impact regarding your household. Spend less and also moment simply by buying an excellent meat grinder. Help make time and energy to initial program slightly, get ready a tad bit more, and luxuriate in any healthy meal a whole lot.

Wagner 0520000 Power Tex Texture Sprayer


  • The Wagner Power Tex is definitely an all in one run texture sprayer–no individual air compressor or even air hoses required! Excellent built-in turbine using more than sufficient power to texture a whole ceiling, however it really is just designed, therefore it is ideal actually for small touch-up jobs. Additionally, since it functions Wagner’s Lock-n-Go Technologies, set up as well as clean up tend to be easily along with no tools needed.
  • The Wagner Power Tex bundle consists of The Wagner Power Tex bundle consists of Wagner Power Tex One-gallon hopper three nozzles (small, moderate, as well as large) Cleansing brush Lubrication Along with Lock-n-Go Technologies, the sprayer functions fast, no-tool set up. This particular sprayer’s hopper changes very easily in order to add attractive texturing in order to ceilings as well as walls. No Compressor? No Issue. The award-winning Wagner Power Tex texture sprayer features the powerful built-in air turbine, which generates enough airflow in order to apply professional-looking consistency upon walls, ceilings, along with other hard surfaces. Since the turbine is actually built into the sprayer, there is certainly no air compressor or even long air hoses needed.
  • The turbine is ranked at 120 volts, 3.7 amps, and 60 Hertz. Wagner Power Tex has brought the “Member Tested and Recommended” seal and the “Contractor Tested as well as Recommended” seal through the famous Handyman Club of U.S.A.
  • Similar product: Wagner 0518080 review, Wagner Flexio 890 review. Wagner 0518050…….


  • A great investment and excellent cost:
    Financially perform the job when compared with spray cans or even hiring an expert.
  • Clean up is extremely simple.
    To wash, just remember to remove the air turbine, the hopper, as well as nozzle through the spray gun. The brush is roofed; clean the parts along with comfortable, water and soap, utilizing the brush. Right after this dries; reassemble the unit with regard to storage.
  • Generates professional results:

 (I obtain outstanding outcomes each time I utilize it.)

  • Great instructions/three textures:

(I have used almost all three textures upon various jobs, as well as they all look solid.)


  • A messy task:
    Texturing might be a messy task along with any kind of gear, although. Become sure in order to cover completely everything, as well as problem solved.
  • Needs some strength:
    Texturing could be a taxing job. It needs upper body strength for a fresh and great workout.

Features of Wagner 0520000 Power Tex Texture Sprayer

  • Sprays at 0.2 GPM for optimal coverage:
  • It features a 1-year warranty:
  • Three spray patterns – knockdown, orange peel, and popcorn – offered enhanced spray control on a variety of surfaces:
  • Maximum pressure 2 psi; built-in air turbine removed the benefits of other air compressor:
  • Accommodates the utilization of aggregated as well as non-aggregated materials with regard to versatile systems:
  • Lock-n-go method as well as integrated cleaning brush with regard to simple cleaning:
  • Stable 3-point stand makes easy hopper filling up:
  • Comfort armrest decreases fatigue whenever spraying:
  • It incorporated air turbine the actual PowerTex very portable:
  • It includes powerful built-in air turbine, 1-gal. Hopper, three spray nozzles, changeable flow trigger:

Customer Score

“ By profession I am a drywall finisher along with 20+ years of practical experience. I focus on guarantee function, water/fire harm, piecework, as well as small renovations. I perform plenty of texture matching as well as I happen to be utilizing a big texture machine or perhaps a compressor as well as hopper with regard to years however, I have developed tired of lugging about all those huge machines for the patch or two. For that reason I chose to buy the Power-Tex, which includes apprehension, because of several very poor reviews together with a video review had been it had been demonstrated used. I opened up the as well as do exactly what should be done first, see the directions! The directions had been clear and concise so when implemented deliver exactly what exactly is guaranteed through Wagner. I used Power-Tex on a few patch jobs together with a 300 sq ft basement.
I discovered this particular to become a general great product for DIY and small/medium application. It really is super handy with regard to smaller jobs or even place wherever you cannot provide the big hopper or even texture machine, ”


Lastly. The Wagner 0520000 Power Tex Texture Sprayer is definitely an excellent product that may fulfill your needs and make you pleased.

Wood Dusts and Dust Collection VS Health Issues

Every woodworker would have been dreaming of having a lot of tools. It could be small or big tools, from the cheapest to the most expensive tools. In woodworking, there are a lot of tools that each of them has different functions, so it would make you wanted to buy everything.

For a beginner, a router might be a great tool to have because it could do most of the basic tasks in woodworking. The best router for a beginner might be Bosch 1617EVSPK with all the power and the features that it has. It also came with an affordable price.

But, there is one feature that every woodworker, both beginner and professional should know. This feature or tool is often forgotten. It’s the dust collection.

A dust collection is a system that works together to collect the dust at it’s source, transport it to a desired location, separate it from the air, then released back the clean air. This system consists of the hood, the ductwork, the collector, the fan, and the after filters (optional).

Dust collection for small shop

You could build your own dust collection system or there are some tools that have their own dust collection inside. If you build it yourself, there are several things that you should really pay attention to make the dust collection to work at it’s finest. When you buy a tool, especially the tool that would likely to produce wood dusts, it’s better to buy one that has a dust collection or the one that would compatible to connect to a dust collection system.

Actually, you could do any kinds and any types of dust collection that you wanted. You could even build it yourself to fit your workshop. But these are several types of dust collection techniques are:

  • Long dust collection

This type of dust collection would have a long pipe or hoses so wherever you move your tools, the dust could still be cleaned out.

  • Cluster type

You could arrange couple of big tools as a cluster, then all of them are connected to two big gallons.

  • A quiet one

You could build a storage room for your dust collection to reduce the noise it makes.

  • A ceiling and wall dust collection

When you mounted all the ducts of your dust collection to the ceiling or to the wall, then your workshop would be free from it’s hanging around.

  • Floor dust collection

It has in-floor dust collection ports that connect to the wall near them, you could put them under a workbench.

  • Floor sweep

This is the most simple yet effective dust collection. It has a bottomless box and the dust collection hole on top of it. You just need to sweep all the dust you have been created then sweep them to the box.

  • PVC type

This kind of dust collection used PVC to connect between each tools and as a canal to collect the dusts that those tools produced.

  • Air filtration cabinet

This is just a dust collection in a cabinet form so you could move them around to filter the air around the cabinet.

A lot of woodworker might not be aware of the danger that came from wood dusts. They might be aware after they got diagnosed. Actually there are a lot more damaged that wood dusts created than just a health issues.

dust collector

Wood dusts on your workshop floor could make you fall down or tripping. For the first time working, you might feel irritated on eyes, nose, and throat. Because the dust is very small, it could hurt you easily especially on the eyes. When it hit your throat it might be considered as pulmonary function impairment.

It could also affect on your respiratory such as asthma. After a woodworker has been getting a lot of wood dusts, it might cause an allergic reaction. Wood dusts even considered as a human carcinogen and it could cause cancer especially hardwoods that would cause cancer of the nose part.

Wood dusts that invisible because it’s very small called the fine dust might be the most dangerous. Because the size of it that people might not be aware of. This could cause decreased lung capacity and other health issues.

Done with the health issues. Wood dusts cloud easily get burnt even by the electric sparks or if you smoke then you just have to be more careful. Of course you don’t want your workshop and home get burnt. You could actually use the wood dusts to make something from it rather than just throw it to the garbage.

Besides having a dust collection, there are several ways to protect every woodworker from those dangers. Such as dust mask, respirator, air exhaust, and vacuum. If you want to really enjoy woodworking and you want your body to be safe and healthy, then these kind of things are really important to have and wear while you work.

Best Smoke Air Purifier for smoke reviews

What to Look out For?

With the environment in tartars and everything going downside, the clean air that nature used to afford everyone is now gone, and we are all left to fend for ourselves. This is hard enough without having a smoker in your home not only putting your life in danger but also that of your children. There is a great deal of best air purifier for smoke out there that can work on getting you clean air, but there are only a few that can be able to get rid of smoke.

best air purifier for smoke

What is special about smoke?

There is a variety of things that your normal air purifier will take care of. Among these are the allergens that include things like pollen, pet dander and hairs as well as the most common which is dust. However, these do very little or nothing to address the smoke issue. This is because there are two components of smoke that most air purifiers are not capable of dealing with. The first are the tiny microscopic particles that come together to form the visible smoke and the second are their larger cousins that merge to form the odor. These are the two factors that make smoke unique and elusive to the other air purifiers.

What to look for in the best air purifier for smoke?

best air purifer for dust

There are a lot of air purifiers will set themselves up as the best in terms of getting rid of your smoke problems. However, do not be fooled, there is only a handful of brands that can brag about this and rightfully so. The best air purifier for smoke should have among other features;

A true HEPA filtering system

This is the only system that has been proven to be able to remove up to 99.97% of particles that are as small as .3 microns. This means that most of the smoke particles will be captured, and hence you will have much cleaner air courtesy of the true HEPA system. This is among the key factors that you should keep your eyes peeled out for when you are looking for the best air purifier for smoke.

Activated carbon

While the HEPA system is incorporated in a lot of air purifiers, the one thing that is quite hard to find is an air purifier that has activated carbon. Not only does this take care of your smoke problems for good, but it also ensures that the odor is history. That way a smoker has the ability to maintain a house without anyone ever knowing that they are a smoker unless they have seen them in the act. The best air purifier for smoke is supposed to have a lot of activated carbon as these helps to absorb the gases and the odors and hence removing all the harmful by-products that are caused by smoking.

Keep in mind that while you might be tempted to buy a variety of other air purifiers that do not have any of the features listed here for the simple fact that they state they can deal with smoke, it will be nothing but a waste of your hard earned money. If you are looking for the best air purifier for smoke, then you have to make sure that it has these features for it to be worth your investment.

Important points to be kept in mind before buying an off road electric scooters for adults

Earlier if you wanted to buy a scooter, then you would have only checked its features such as average, weight etc. But now it’s not at all easy to buy a scooter, as there are several varieties available which makes it difficult for a person to choose from.

off road electric scooter

Gas scooters and electric scooters are the two most common and popular varieties of scooters being used these days. In these two varieties only, you will find several models which are quite brilliant. To make things easy for you; let’s have a look at some of the important points which need to kept in mind before buying an off road electric scooters for adults. eScooterboxhas listed them for you.

How much will you travel on scooter?

  • If you are planning to buy a scooter for long distances then a gas scooter is a much better option than an electric scooter. While traveling, you need to refill gas which is easily available as several gas stations are located after short distances. While traveling with an electric scooter, you need to charge your battery after regular intervals. It will take hours to fully charge the battery, so prefer a gas scooter over an electric scooter for long distance.

Do consider maintenance cost of a scooter

  • Maintenance cost matters a lot in the selection of a scooter. A gas scooter has several benefits over an electric scooter but when we talk about the maintenance cost it is far behind from the electric scooters. Gas scooters require maintenance after every few months, whereas an electric scooter requires maintenance after a year or may be two years. So, do consider the maintenance cost of scooter so that you do not have to regret your decision afterwards.

Check the life of a scooter

  • Purchasing a scooter is not a short period deal as you buy a scooter to use its services for years. So, it’s really important to check the life of a scooter before buying it. A gas scooter will start giving you problems after few years if you do not maintain it properly whereas an electric scooter will work properly even after years as you only need to maintain the battery. So, if you are planning to buy a scooter for longer period then prefer adult off-road scooter.

Prefer environment friendly scooters

  • Apart from maintenance costs another major benefit enjoyed from electric scooters over gas scooters is that these are more environmentally friendly. An electric scooter never emits any polluted gas as it works on battery whereas a gas scooter plays a major role in polluting the environment as it emits several polluted gases. So, prefer to buy an electric scooter if you want to save your environment.

These are some of the few important points which you must consider before buying a scooter. Even though an electric scooter is much expensive than a gas scooter but its low maintenance cost makes it a better option than gas scoters. So, check out top 10 electric scooters for better options.

How to choose a Downhill Longboard?

Innovators identified that will extended decks, delicate urethane wheels, vast trucks are generally greater pertaining to coping with your high-speed downhill racers. A new downhill longboard like the quest super cruiser will be the excellent aboard just for this. However you can be a beginner along with need to discover precisely what your enjoyment is centered on along with you need a very good healthy aboard. Precisely what aboard are you looking to decide on?

Downhill Longboard

How to choose :

You can decide on just about any deck along with it is usually build as being a downhill longboard, nevertheless authorities who may have utilized in numerous snowboards deducted that you have generally 2 deck variations which have been ideal equipped pertaining to downhill longboarding. Read the following tips:

  • A great deal of longboard racers choose to decline by way of longboard if you undoubtedly desire your speediest means along your incline using high-speed, nearly all racers observed which a prime mount longboard is the foremost.
  • Decline by way of longboard features divots in sometimes facet in the aboard wherever your current trucks are generally slipped by way of.
  • Quite often it is just a shaped aboard so this means, it doesn’t matter if your current longboard for the front as well as conversely, the two include the very same.
  • It can be additional dependable so you are generally decrease on the terrain supplying you with a reduced center involving the law of gravity, which supports anyone while using stress and anxiety throughout high-speed.
  • By simply selecting the best patio sizing, select your extended versions when you find yourself a new beginner.
  • It’s going to be a lesser amount of maneuverable, nevertheless it’s going to be superior to experiencing unsound with a small aboard.
  • Down snowboards normally cover anything from 37″- 43″. Should you not determine what period you desire, go with a mid-range with regards to 40-41″. Select the dimensions of your current sneakers to the wider, so you are generally often okay.
  • For those who have accomplished a number of mountains along with feel relaxed while using rate, however you desire more rapidly along with need to try out high-speed, you’ll be able to go with a mount longboard.
  • This is to the advanced beginner along with innovative racers. A top-notch mount longboard is often a shaped longboard devoid of the divots in sometimes facet.
  • Regardless of which in turn facet you happen to be employing using this type of aboard plus the trucks are generally alternatively fitted right within the aboard as an alternative to by way of.

Above all, the mount longboard provides greater functionality when you’re in along tough mountains. Another thing that may be really important for you to discover how to slow throughout small sides this also aboard will assist you to using this type of. Accomplishing this which has a prime mount aboard is very simple when compared with which has a decline by way of aboard.

Current events: can EMFs hurt you?

Many scientists and environmentalists are concerned that the EMFs generated by electric appliances and high  voltage power lines may harm health. Studies have not provided a clear answer to the question of health effects. Ways to reduce exposure are presented.
Can power lines and electric appliances promote brain cancer, leukemia, birth defects, and other diseases? The debate is charged with emotion.

What Are EMFs?

Electromagnetic fields, or EMFs, are electric and magnetic fields produced by electricity. Your CD player, hair dryer, television, and washing machine all use 60 hertz (Hz) alternating current (AC). The direction of the current shifts, or alternates, 60 cycles per second.
Health concerns focus on the magnetic field, measured in units called milligauss (mG). Some common appliances, like can openers and motor-driven alarm clocks, produce strong fields close up, but the field’s intensity drops off quickly a few feet away.
EMFs from 60 Hz power are “extremely low frequency,” in contrast to other radiation along the electromagnetic spectrum, such as X-rays or microwaves. Some EMFs exist naturally (e.g., the Earth’s magnetic field makes a compass point north).
EMFs from 60 Hz power can’t break apart cell barriers or heart tissue. Still, many scientists, citizen groups, and environmental activists worry about possible health problems.

Clusters of Cancer?

Concern about EMFs began in 1979 when researchers Nancy Wertheimer and Ed Leeper published a study that found a correlation between high EMFs and childhood leukemia deaths in Denver.
Electric utilities criticized the researchers’ methods. Scientists began new studies, looking at brain cancer, leukemia, Alzheimer’s disease, birth defects, and other illnesses.
Meanwhile, people living and working near high voltage electric wires and substations worried about cancer clusters concentrations of cancer within small geographic areas. Residents on Meadow Street in Guilford, Connecticut, claimed that an electric substation caused four cases of brain cancer, as well as other diseases. Teachers at Slater School in Fresno, California, said that EMFs caused at least eight cancer cases among teachers and aides working closest to high voltage transmission lines.
Journalist Paul Brodeur alerted the public with articles in The New Yorker magazine and books titled Currents of Death and The Great Power Line Conspiracy. Critics responded that cancer clusters can and do happen by chance.
Hundreds of studies have been done, costing millions of dollars. The National Council for Radiation Protection and Measurements soon will issue a 1,000 page report summarizing these studies.
Despite all these studies, there’s no clear answer. Interested parties have accused each other of selective reporting: picking and choosing data to get a particular result.
When health effects are found, scientists often are unable to replicate, or duplicate, the results in other studies. Some studies flat out contradict each other. One study found a relationship between EMFs and brain cancer, but not leukemia. Another found just the opposite.
Even if 60Hz EMFs don’t cause cancer, some scientists suspect they might promote growth of tumors that start some other way. Studies suggest EMFs slow production of melatonin, a hormone believed to fight cancer. Other studies examine whether EMFs alter the flow of calcium ions from cell to cell.
Fueling the fires are high financial stakes. Relocating transmission lines from overhead to underground would cost millions, with no guarantee that public health would benefit. And utilities and appliance manufacturers could face billions of dollars of potential liability if EMFs were ever proven to cause disease.

What Can Be Done?

While scientists debate whether EMFs pose a health risk, what can you do? First of all, keep things in perspective. Possible health problems from EMFs are rare, presenting much lower risks than many known hazards, such as the chance of an auto accident.
Yet uncertainty about even a small increased cancer risk can cause great fear. Finding out about the fields around your home can help. Some electric companies will measure EMFs with a special instrument, called a gaussmeter, free of charge.
Remember that EMF strength drops off quickly as distance from the source increases. Readings 4 inches away from a television can go up to 1 00 mG. Three feet away, the range is almost undetectable.
Using this information, Carnegie Mellon University Professor M.G. Morgan and his colleagues have suggested that people worried about EMFs use these low cost or no cost measures to reduce exposure: Move your motor driven plugin alarm clock across the room and away from your bed, or get a non motorized LED model or wind up clock. Warm the bed with your electric blanket, but turn it off and unplug it before going to sleep. Limit use of electric shavers, or switch to a manual razor. Using the best vacuum for stairs to avoid the harmful effects of EMFs. Keep the computer monitor at arm’s length and stay 3 feet away from the backs and sides of other computers. Stay at arm’s length when running kitchen appliances and other electrical equipment.
Since scientists don’t agree on whether EMFs can hurt you, neither they nor the U.S. government has determined what “magic number,” if any, is “safe.” And, since electricity is all around you, it’s a good idea to practice prudent avoidance.

Foodsaver V2840 review – The Best Surprise Kitchen Gift

My sister thought that I wasted my money when I bought the best vacuum sealer the Foodsaver V2840 Advanced Design. She said it had been unnecessary and results in our kitchen space just. I simply shrugged it off and waited until my week-long a vacation to the populous city. After that week as I got back soon, all I noticed were “Many Thanks” and inch “I really love you”. Exactly what do you consider did I actually do?foodsaver-chart

What I did has been make different meals and desserts on her behalf before me remaining and sealed all of them utilizing the machine. Nicely, it had been her birthday celebration that week, and I understood she was usually in a morning rush. Without me in order to cook on her behalf, she would be eating nasty, unpleasant meals (yes, she actually is bad at your kitchen).

As a week-long present for her birthday celebration, I ensured that whenever the freezer is opened by her, there will always be different things and delicious to eat on her behalf. Plus yes, my strategy worked. She loves the FoodSaver Meals Sealer just as much as I do now!

Adorable Features:

Using its flip-up space-saving style, getting a kitchen space is not a nagging issue at all. The business that brought us the product has taken into consideration how limited ones kitchen area space is certainly, and has recognized that product is not a simple to every kitchen really. Well, yes it cannot really a basic, yet it’s definitely the must-have! The flexible meals settings are also outstanding.

Who’s It Made For?

This particular best vacuum sealer is for all those customers who want to purchase in bulk to get all of them at a low price. Using they can be helped by it seal these food types into smaller packs, and be saved within the freezer for potential consumption. This is big money and time-saver definitely. The good thing is that, dinners and desserts you have sealed taste as if you cooked them once you reheat them just!

The particular “Gasket” Issue:

Nicely, there’s this seal issue that quite a few consumers have already been whimpering about — yet I don’t! The thing is that the device stops giving a whole vacuum due to the issue with the gaskets. The solution is easy downright, and an easy problem such as this is not able to outweigh the product’s efficiency.vasmaster vacuum sealer roll

According to the majority of consumers, some tips about what these people perform: First, you need to remove both bottom and top gasket. Next, stick it within about 1/4 drinking water with a pea-sized level of a liquid meal cleaning soap. After squeezing the soap thoroughly, rinse it along with clean drinking water. Lastly, let it dry first every day and night before replacing it to the device. Therefore, the trick to avoiding any pressing issue with the machine is to clean it often.

Overall, I have, but still believe that this undoubtedly among the best purchases I had for the kitchen area. Buying it is worthwhile for all the comfort it offers and for the long- phrase saving it could give you with regards to every day usage of food. It is a definite must-have for each and every kitchen pro.

What you need to get the job done

If you’re an off roader, chances are you’ve got a bunch of tools in the garage. More than likely you also carry tools in your 4×4, just in case something goes snap in the night. Do you have what you need? Are you ready to step up to more advanced repairs and installations? Should you buy brand name tools, or will the cheap stuff suffice? Let’s explore!


We’ve all seen the low buck tools that sell for a fraction of the price of the name brands. Chances are, you’ve had one of those el cheapo wrenches spread open when you were trying to free a stubborn nut.

Sure, the top of the line tools such as Craftsman Professional, Snap On, Proto, Mac are expensive, but there is a second level of tools that are excellent and priced substantially less than the premium items. Among them are Craftsman Power Kraft and SK.

Our advice? If you can afford the very best, go for it. If you’re on a budget, it’s hard to beat Sears’ Craftsman. The most important thing you should look for is a good guarantee. Craftsman tools are famous for their lifetime guarantee; if you break a hand tool, just bring it back and Sears will replace it. Many other tool makers have been pressured to follow that lead. The lifetime guarantee does not apply to power tools.

Will cheap tools work? Yes, and some of them have a limited guarantee. For example, I have a large number of low cost screwdrivers, box wrenches, crescent wrenches, hammers, files and pliers. And the tools that I stash away in my off-road vehicles are carefully chosen low cost items.


END WRENCHES: When choosing end wrenches, your best bet is to get a combination set; one with a box wrench on one end and an open type on the other end. A proper set of end wrenches will get shorter as the wrench size decreases. This is a sort of built-in protection against over tightening.

Open end wrenches apply their force on two sides of the nut or bolt. Box wrenches apply force on all six sides of a standard fastener, so you’re always better off using a box end, rather than an open end, if you have the option.

ADJUSTABLE WRENCHES: Commonly referred to as Crescent wrenches, these are the most versatile tools you can carry. A 10 or 12 inch wrench will handle fasteners from zero to more than an inch.

SOCKET WRENCHES: These greatly speed up work compared to end wrenches, and can often work in spots where an end wrench wonts fit. You should have a full range of sizes from 114 inch to 1 1/2 inches (or the metric equivalent), and a good selection of extensions. Ideally, you should have 1/4 inch, 3/8 inch and 1/2 inch drive sets. However, if you’re on a tight budget, go with the medium sized 3/8-inch drive set and purchase a 1/4 inch adapter and 1/4 inch sockets.

Sockets are available in 4, 6, 8 and 12 points. The 4 and 8 point sockets are for square headed fasteners, while the 6 pointers are used mainly for power impact tools. For most general use, the 12 point sockets get the nod.

SPECIALTY RATCHET TIPS: In addition to sockets, you can purchase a wide variety of tips to speed up most jobs. They include swivels, screwdriver tips, torx bits, Allen tips and ratchet spinner attachments.

HOLDERS: Get a medium sized vise and attach it firmly to a stout bench. This will be one of the most heavily used items in your tool arsenal. While you’re at it, pick up a few cheap C clamps.

SCREWDRIVERS: Don’t take this common tool for granted, because an ill fitting blade can chew up a screw. Get a good selection of straight slots, and both versions of the cross slots, the Phillips and Reed and Prince heads. Cheap, ultra long screw drivers can be used for prying things loose. One step beyond the screwdriver is the best impact driver. This handy tool will loosen stubborn screws (or even nuts/bolts) by whacking it with a hammer and applying sharp jolts of torque.

PLIERS: Snap On makes more than 40 different types of pliers, but only a professional mechanic would need them all. You should have at least the following: double jointed straight jaw pliers, long nosed (needle nose), diagonal wire cutters, vise grips and Channel locks. Beyond the basics, you can also purchase pliers that remove/install snap rings and circlips, remove spark plug terminals, strip electrical wiring and remove brake springs, among other tasks.

HAMMERS: There are times when a hammer is needed to free a stubborn part. In addition to the garden variety claw hammer, you should have a round faced ball peen, a soft faced plastic or rubber hammer and a stout lead or copper hammer for tapping metal without damaging it.

SAWS AND FILES: Never cut corners on hacksaw blades; a premium blade will not only out cut a cheap blade, it will out last it many times over. Get two blades: one should be a fine toothed item of 32 teeth per inch for cutting harder steels, and a blade in the 18 to 24 teeth per ins range for coarser cuts on softer materials.

No matter how clean your hacksaw cut is, it must be dressed up with a file. You’ll need a selection of files from fine to coarse, with a variety of shapes, from round (rat tail) to flat.

TORQUE WENCHES: Every nut, bolt, or piece of metal has a limit to which it can safely be stretched or stressed. Pro mechanics say that an over torqued bolt is half broken. To prevent over tightening (or under), a torque wrench is a must! For light duty tightening, you’ll need a torque wrench in inch pounds; for heavy duty work, a foot pound wrench is needed.

Two types of torque wrenches are available: the dial type has a pointer that indicates the tonque applied, and the clicker type that makes a clicking sound when the pre set torque is reached. Usually, tire dial type wrenches are cheaper than the clickers, but work well providing you’re in a position to read the dial.

JACKS AND STANDS: These are must haves for off roaders, as we’re always swapping wheels, or crawling around under our 4x4s to fiddle with one thing or another. Get a decent hydraulic jack with at least a 2 ton capacity. Pick up four adjustable jack stands capable of holding the 4×4’s full weight.

LIGHTS: Get a good drop light and plenty of extension cords. The best one I’ve ever seen is by Snap On, and it has a super powerful magnetic base that lets you stick it against any metal surface and aim it at the work area.

ELECTRICAL TESTERS: At the very minimum, you should have a basic circuit tester that will let you trace out shorts, opens, or find a hot wire. Beyond that, a small ohmmeter can solve numerous puzzles.

Electrical Testers

MEASURING DEVICES: Acquire a tape measure, feeler gauges and a cheap set of calipers.

TIRE STUFF: A cigarette lighter powered portable air compressor can be a real life saver at times. You’ll also need an accurate tire gauge.

HANDLING LIQUIDS AND LUBRICANTS: Every home garage should have a decent selection of funnels and drain pans. Grease guns are cheap; mini guns are available for less than ten bucks. A one dollar turkey baster makes a great battery filler.

SPECIALTY TOOLS: You are limited in this area by how deep your pockets are. There’s a near-endless variety of handy tools designed for special jobs. Some you might consider are: gear pullers, pop rivet guns, tin snips, propane torches, tap and die sets, timing lights, hex head (Allen) wrenches, screw extractor sets, compression testers, welding outfits to name just a few.

METRIC OR REGULAR? Get both. Even though the world is slowly shifting to the metric system, it’s common to find both types of fasteners on American vehicles. And if you have an older 4×4, chances are all nuts and bolts will he US, Japanese and European 4x4s are fully metric.

POWER TOOLS: There are two power tools every 4×4 owner absolutely MUST HAVE in his home shop: an electric drill and a bench grinder. If you can only afford one drill, get the larger unit with a 1/2 inch chuck that will accept larger drill bits and accessory shafts. The bench grinder should have a wire wheel on one side and a grinding wheel on the other. You’re better off buying a small selection of high quality drill bits than a large number of cheap bits. To complement the drill, get a nice selection of wire brushes, grinding stones and small cut off wheels. This will help you make short work when removing rusted exhaust pipes, or corroded fasteners.

Other power tools worth considering are sawzalls, impact guns, soldering guns, small hand grinders, a one horse air compressor with a selection of blow tips, a polishing/buffing wheel (great for getting brush scratches out of your paint job), and a battery charger. Of course, the list of power tools is almost endless, and you could go nuts!


Mountain biking is the ultimate antidote to self-implosion

YOU DON’T HAVE TO BE AROUND TIM COMMERFORD very long to understand how obsessed he is with mountain biking. The mere mention of bikes or trails will set the Rage Against the Machine bassist off on an animated rant about the virtues of riding mountain bikes as a way of life.

For the 47 year old rock luminary, riding is a passion that runs as deep as his drive to create hard hitting music. And over the past two decades, he’s easily spent as much time in the saddle as he has behind the bass.

This fact became plenty clear during a late April ride with Commerford in the hills behind his home in Malibu, California. From the moment we hit the fire road leading up to our Santa Monica Mountains route, it was obvious that the lanky musician was used to riding fast and free. Barely two months off a lower back surgery, he was charging up a sustained climb and chatting away with the familiar ease of a talk show host.

“I love how I get to forget everything that’s happening in my world and reset my brain and just focus on what I’m doing on my bike,” he told me as I struggled to keep up. “I can’t tell you how many times I’ve finished a long ride and then didn’t even remember what I rode.

“Quite often I’ll go for a ride and end up on some trail that I’m not even used to, and then at some point I’ll go, ‘Where am I?’ I’ll just completely zone out and forget where I’m at.”

Commerford first learned about this instant reset in 1993, when his future father in law, bodybuilder James ‘Jimbo’ Insko, introduced him to mountain biking. He soon bought a chromoly Trek 930 hardtail and started exploring the Santa Monicas as a diversion from his bass playing duties with Rage Against the Machine, a seminal rap metal band with heavy political overtones.
“By 1995, I had my bike with me anytime I went on tour,” Commerford says. “I’ve ridden a lot of different places in the world. As soon as we’d arrive to a new city I’d build up my bike and start exploring. It was such a great way to see a new place.

“Going on tour was two sides of an amazing coin. I got to be part of an incredible musical experience and then travel the world in the best way that you can. And that’s on a bike.”

Inspired by some of the sport’s early heroes such as John Tomac, Hans Rey, Shaun Palmer, Brian Lopes, Myles Rockwell and Steve Peat Commerford delved deep into mountain biking, developing an appetite for virtually every discipline, from cross country to downhill to dirt jumping.

“You name it, I’m into it,” he says. “These days I’m more into big cross country rides, though. I love to go out and just ride for hours and just lose myself. And I love climbing, especially technical climbs. I just love that challenge and the feeling of cleaning something that looks impossible to climb.”

If my ride with Commerford was any indication, those words are an understatement. In just a few hours, we rode over 20 miles, with more than 4,000 feet of climbing. And he never let up. The steeper the trail got, the harder he charged, attacking ridiculously steep sections with an impressive combination of power and finesse. Once at the top, he’d turn around and ride back down so he could try an even tougher line.

“Tim’s whole life is a game of engagement,” says his neighbor, 21 year old Marshall Mullen, who began riding at age 12 after seeing Commerford whisk by his house every day en route to the Santa Monica Mountains. “He’s so intense and competitive with everything he does, and he puts everything he has into it, whether it’s riding, or working on the pumptrack, or working on music. He’s 110 percent engaged in everything he does, and I think that’s partially why he’s so successful. He’s either in or out. There’s no middle ground for him.”

To be sure, Commerford’s intensity is palpable from the moment you meet him. The wiry 6 foot, 4 inch tall bassist is covered in lean muscle, suggesting a man half his age. He speaks with a tone of measured assuredness, his steely gaze hinting at a rare earnestness of character. Whether talking or riding with him, it’s clear that he has zero tolerance for bullshit. And listening to him grunt and growl while climbing up a ledgy stretch of slickrock, it’s easy to see how he’s been such a force on the bass, from his Rage Against the Machine days through the Audioslave years and on to his current band, Future User.

“With Rage, it really was ‘politics and rock ‘n’ roll’,” Commerford says. “When we’d go on tour, our main goal was to go onstage, play the best set we possibly could and just destroy everyone on the bill. It didn’t matter who we were touring with. We always just wanted to blow them off the stage. And we usually did. In all those years, I can only think of a couple of times when that might not have happened.”

Riding with Commerford might be as intense as touring with him and his band. Every climb is a race to the top, and every technical section is a bike handling contest. He and his riding buddies routinely play a game of ‘dabs,’ tallying up the number of times each rider puts a foot down, with the lowest score taking the win. Even on my ride with him, it seemed that the dab game was afoot, with Commerford good naturedly heckling the much younger Mullen whenever he’d lose momentum up a techy ascent.

“I remember one time I was trail riding with Lance (Armstrong) and he easily beat me to the top of a climb, but I saw that he’d dabbed a few times on the way up,” Commerford recalls. “When I caught up to him he started to rub it in, but I just told him that the way I figured it, I’d won because I’d cleaned the whole climb without putting my foot down. That’s what mountain biking is all about.”

Though Commerford now rides a pimped out Trek Remedy 9.8 that he describes as “the sickest bike in the world,” for years his go to bikes were downhill and freeride sleds, which he would muscle to the tops of the Malibu area hills before bombing down the other sides.

“I used to use a dog collar to cinch the fork down between the crowns for the climbs,” he explains. “Then before I’d go down I’d take the collar off and let the fork open up for the descents. It was a good system, and powering those heavy bikes up the hills made me a lot stronger.”

One look through Commerford’s garage is like a lesson in mountain bike history, with an enviable assortment of vintage hardtails and several generations of groundbreaking gravity oriented rigs. He practically has the entire evolution of Santa Cruz Bicycles’ full suspension line hanging from the rafters, from the first generation, single pivot Superlight to a well worn Heckler and a decommissioned Bullit. Concealed among a pile of old wheelsets is a stripped down Intense M1 downhill bike, while in a corner lies a beat up old Intense Uzzi VPX.
“When I get that bike dialed, it runs as good as any bike out there today,” Commerford claims. “I know it has 26 inch wheels and everyone thinks those are outdated, but sometimes I wonder if 26 isn’t better for that kind of riding.”

Underneath his workbench are several drawers filled to the brim with old components, including one crammed full of discarded front and rear derailleurs.

“I’m pretty sure every derailleur I’ve ever owned is in here,” he says with a smile. “I think I’ve got every version of (Shimano) XTR that’s ever been made. I’ve always loved XTR. To me, having a set of XTR cranks is like having a Rolex. And Shimano XTR brakes … are you kidding me? There are no other brakes like that. They work so good, and when you wear the brake pads down and replace them, the moment you slide the wheel back in the brakes are perfectly centered on the rotor. I love it when things just work like that.”

If Commerford’s garage is a snapshot of mountain bike history, then his battered body is a testament to a lifetime of crashes, injuries and surgeries. His knees and shins are covered in scars, with the unmistakable tattoo on his left leg pockmarked in discolored scar tissue. His list of surgeries is long, from the human cadaver graft in the AC joint of his left shoulder to the screws in his left pinkie finger and the two metal plates in his skull.

“I had to get those after a really bad crash I had on the way to a Rage rehearsal,” he states matter of factly. “Back then I thought you always needed a lot of speed to hit jumps, and I went way too fast into a big jump and overshot it. All I remember was that feeling of being scared, and the next thing I knew I was waking up in an emergency room.

“They had to put two metal plates in my skull. One is under my left eyebrow, and the other is in my left cheek, connecting my upper jaw to my orbital bone and eye socket.”

Though injuries have taken a toll on Commerford, he insists that he is better off for them.

“If there’s damage there, I’d like to think that the constant blood flow that comes from riding is ultimately going to keep me alive longer,” he says. “Even though mountain biking is what has injured me, it’s also what’s made me feel the best I’ve ever felt in my life. The injuries I’ve had are all better because I ride.”

Given Commerford’s celebrity status and the often fickle nature of relationships in the entertainment business, mountain biking also represents a retreat to a community of like minded individuals.

“When you meet someone who is such a solid rider, you know that the bike has taken up such a large portion of that person’s life, and that immediately means that you have something fundamental in common with them,” he explains. “All of my friends are pretty much people I ride with. I meet people through riding, and most of the relationships I have with people are on the bike.
“It feels good to grow old and have a sport that I can do forever,” he adds. “It’s a religion, man not just some hobby. It consumes me. I spend a lot of time thinking about it and I go to bed every night dreaming about it.”

Raptor speed: the mountain town of Eagle, Colorado, has quickly become a singletrack Utopia

“But it really hurts” says Zachary, a 9 years old MTB 101 camper who’s pointing to scrapes on his arm and leg after an accidental mid pack frontflip on the sidewalk.

“Well, the thing about getting hurt is that it hurts less and less with every minute,” says Vail Valley Alternative Sports Academy (WASA) co founder Mike McCormack, who continues with some encouraging words. “Should we go catch up with our friends?”

Zachary hesitantly buckles his helmet and returns to the saddle. The pair cruises along Eagle Ranch’s spacious sidewalks, pedaling past fairways and impeccably manicured yards decorated with lacrosse nets. Within minutes, we meet up with a couple dozen kids ranging in age from 7 to 11 gathered at the entrance of a foot wide dirt trail that contours the green space between the sidewalk and the road. They’re champing at the bit most of the kids ride this three block section of trail twice a day, to and from school. Some of them even helped berm out the corners to encourage small tires to stay in the tread. It’s the first phase of Eagle’s well publicized Single track Sidewalks, a ‘flow to school’ program that plans to connect seven neighborhoods with Eagle’s two public schools and area trailheads.

Zachary watches the first group of kids charge the trail. They’re right on the wheel of WASA co founder Karen Jarchow, pedaling, pumping and jumping the rolling grade reversals that look a lot like tabletops when you’re on 24 inch wheels. As the bikes get smaller and the helmets more bobblehead ish, Zachary cautiously files in. Thirty feet downhill where the trail meets sidewalk, he’s breathing heavily through a big smile the crash forgotten, confidence restored.

When McCormack moved to town with his wife and two young kids a few years ago, he noticed little footpaths within the landscaped buffers in Eagle Ranch, a 1,900 acre golf community located just southeast of Eagle. McCormack saw an opportunity for kids to experience “five minutes of bliss” on their way to school. “A brief endorphin rush, the wind in your face … that’s why we all mountain bike, right?”

Drawing from his experience co founding the Mountain Bike Junior League in nearby Summit County, Colorado, McCormack sold the idea to trail builder Matt Thompson of Momentum Trail Concepts, Eagle County planner Adam Palmer, who heads the local trail advocacy group Hardscrabble Trails Coalition, and Eagle Mayor Yuri Kostick. The town unanimously approved the plan last November. Singletrack Sidewalks isn’t just about physical activity. The program teaches trail stewardship, environmentalism and accountability the kids help flag, design, build and maintain trails. “It took a village to get the first segment done,” says McCormack.

The program is a prime example of Eagle’s recent efforts to establish itself as Colorado’s one stop mountain bike town. With thoughtful, user friendly trail development, cycling centric city planning and new festivals and races, the town of 6,500 residents is gaining national attention for using mountain biking as an economic driver. Mayor Kostick earned the National Interscholastic Cycling Association’s Community Impact Award for bringing together public and private landowners and stakeholders to build the Haymaker trail that hosted the Haymaker Classic Colorado High School Cycling League State Championships last year. And Colorado Governor John Hickenlooper singled out Eagle as a model cycling community at the Colorado Bicycle Summit last February.

“Everything that needed to happen came together,” says Kostick. “We [Kostick and other local politicians who ride] had the political support from the community and when we were elected, we followed through with actually implementing new trails, building new amenities and improving river access. It’s been so well received, there’s no turning back from the course we’re on.”

It’s one that’s proving incredibly successful. During the high school championships, several Eagle restaurants and breweries pulled their busiest days ever. And though Eagle Ranch was built as a golf course community, real estate agents now advertise the trail system as its No. 1 amenity. The town budgeted $125,000 for recreation based tourism in 2015, up from $80,000 last year.

Halfway between Denver and Grand Junction, Eagle’s high desert climate (and its reputation as a donut hole of sun when it’s storming everywhere else) means the trails are ready to ride in April and dry until mid December. That’s about four more months of riding than you’ll find in Vail, just 30 minutes east.

After stints living in other mountain towns like Breckenridge and Carbondale, McCormack revisited Eagle a few years ago and saw a family friendly community with unbelievable trail access. He lives 100 feet from one of the main trailheads and three blocks from his kids’ elementary school. “All the riding is accessible from town,” says McCormack. “Unlike Fruita, where you have to drive to a trailhead, you can park anywhere and there’s singletrack close by.”

Thompson, the Momentum Trail Concepts founder, says it’s that accessibility that breeds an authentic mountain bike community. “You can park downtown and start and finish any ride from the Mountain Pedaler bike shop or Yeti’s Grind coffee shop,” he says. “And for people who live here, your driveway is your trailhead.”

The town hired Thompson to build the Haymaker trail last year. When he first drove from Denver to scope the project three years ago, he pulled over on a side street to take a call. A group of kids playing street hockey told him to move his truck.

“I called my wife and said, ‘We need to put the house on the market we’re moving to Eagle,'” says Thompson. “I knew it was where we should raise our son. Kids rule the streets in Eagle. The bike racks at school are full every day. My 9 year old is thrilled to live here.”

Haymaker’s loop flows through the lower sage and pinon that surrounds Eagle and returns with huge berms, tabletop hits and sprawling valley views. This summer, Momentum was planning a 1.25 mile extension.

Dominating Eagle’s horizon, the appropriately named Hardscrabble Mountain and its fellow peaks, the Seven Hermits, offer rolling sage singletrack along their flanks, while the upper reaches beckon with loam filled aspen alleys. The Sawmill trail places riders above timberline nearly 4,000 vertical feet above town. Along the lower reaches, you’ll find the lunch loops of Eagle Ranch. Most locals end their rides with a roller coaster finish down Bailey or Mayer Gulch. This year, pending approval from the Bureau of Land Management, Momentum will reroute the School House Rock trail to create better intermediate access to the Hardscrabble network. But it’s the 3,000 plus foot descent from the top of Hardscrabble to Eagle that Mayor Kostick is most excited about. That’s about 1,500 feet higher than the top of the existing Pipeline trail.

“We need to get the Forest Service and BLM on board, but it could be on par with the Whole Enchilada (ride in Moab),” says Kostick. “It would put [Hardscrabble] on the map as one of the rides you have to do in Colorado.”

For those just passing through town, the Boneyard trail network begins minutes from the Eagle exit off Interstate 70. Designed and built by Eagle legend John Bailey (the architect of the 1996 Olympic mountain bike course in Atlanta), Boneyard climbs 3.2 miles to the top of Bellyache Road, then descends on the newly realigned and mellowed Pool and Ice Rink trail which formerly required a 7 inch travel bike and is now more suited to a bike with 5 inches of travel or the slightly more rustic, exposed Redneck Ridge, which Thompson also recently tuned up.

Through his PR and event agency, McCormack runs the Eagle Outside Festival and he worked for three years with local, state and federal land management agencies to permit a new backcountry course for the endurance cross country race, the Firebird 40. This year’s route traveled through four ecosystems, from sage dotted high desert to snow filled alpine meadows, and showed off some of Eagle’s best trails, including Mike’s Night Out, World’s Greatest and Pipeline.

“A significant challenge for riders new to Eagle is the sheer size of its surrounding trail network,” says McCormack. “The race shows riders a rich diversity of trails, some of them difficult to locate at first without a directional arrow or two. It’s hard to develop a sense of this from town, but there’s a little bit of Crested Butte up there. Some Fruita. And a fair dose of Vail.”

The second phase of Singletrack Sidewalks began late this summer. The new section routes through open space, eliminating two busy road crossings.

“The shit is officially being ridden out of Phase One,” says McCormack. “You can’t drive or walk by without seeing kids or adults on it. In the mornings, when school is in session, it’s like a superhighway. The sheer volume of use serves as proof of concept. We’re going to keep at it.”


STAY | AmericInn has rolled out the welcome mat for riders, offering affordable rates, bike storage and an on site bike wash. Several other mid range hotels are within riding distance of all Eagle trailheads. Sylvan Lake State Park, approximately 13 miles from Eagle, offers campsites, yurts and cabins around a scenic, 42 acre lake that’s also a stand up paddleboard destination. In town, grab a shower at the Eagle Pool, right next to the BMX track and the Haymaker trailhead.

DRINK | Both of Eagle’s breweries Bonfire Brewing and 7 Hermits Brewing Company are excellent and support the mountain bike community by raising funds for trail maintenance and building through the sale of seasonal brews. The back patio of the Dusty Boot provides epic sunsets, big burgers, plenty of Colorado beer on tap and an outdoor tiki bar that dispenses frozen boat drinks by the bucket.

GO | Eagle is a high desert climate, but riders can access three different environments from town, so pack accordingly. The Mountain Bike Eagle guidebook is so helpful, it’s almost mandatory. MTB Eagle and the town’s EagleOutside website (eagleoutside.com) offer GPS driven mapping programs accessible from your smartphone.

What if all the bells and whistles are overrated?

THE GUY AT THE HARDWARE STORE OBVIOUSLY KNEW HIS power tools. And, to give him due credit, he was just doing his job. “Don’t even bother with those Milwaukees,” he said. “They’re behind the curve when it comes to batteries. If you want to go cordless, Makita‘s new brushless motors are the way to go. But these DeWaits, the ones with the 20 volt batteries, they’re pretty good too. You gotta try to get the best battery for your dollar. Guarantee you though, that there’ll be something a lot more powerful a year later. That’s just how it is. But these new brush less motors, you combine one of them with a really good battery, and you’ve got a tool you can run for a few years. You just won’t find it for cheap.”

Much as I love me some power tools, I was having trouble paying hundreds of dollars for battery powered drills and Sawzalls that only seemed to come bundled in ‘value added’ packaging. And I was skeptical. The last time I had bought a cordless drill had been in the previous century, and the thing just plain sucked. But, there I was, hoping to damage timber far from any power source, being confused by choices. I needed to chop through some wood, and I needed to join a few other pieces of wood together. I didn’t need an LED worklight to illuminate the job. I didn’t need a portable cube stereo that syncs with my phone’s Bluetooth. I didn’t need an accompanying color matched tote bag. Rad as all the bells and whistles are, I just didn’t need them. This, I realized, was how I was beginning to feel about mountain bikes.

Last winter, I went to New Zealand. I bought a new carbon fiber bike just before leaving. It was full of the latest stuff and was the one of the darlings of the media last year, garnering high praise from almost anyone who tested it. I built it up, and rode it the entire month at the bottom of the world, then sold it. I expected that I would regret the sale, and that there would be some sense of nostalgic attachment associated with the bike. Instead, I felt nothing. It had been a competent tool, had served a purpose, and when it left, I didn’t even feel a twinge of remorse. This is something I have written about before. It is hard for me to get attached to carbon bikes built in Asian factories, regardless of how well they function.

By summertime, I had packed in a good winter and spring of riding, but my carbon fiber squishy bike was gathering dust. For the riding around Santa Cruz, I was reaching for either my one speed hardtail or my rigid ‘cross bike. My very rad and capable carbon fiber mountain bike has 29 inch wheels with 2.4 inch tires, 135 millimeters of rear travel, a mighty long wheelbase, and most of the time, it felt like too much bike. Great for ripping down Pauley Creek above Downieville or getting beaten around the Lakes Basin, but at home on the coast it felt like I was trying to drive a bus down most of the trails. It dawned on me that since I was riding regularly on a rigid bike, that maybe a new hardtail would be the ticket. And since I wasn’t feeling any sentimental attachment to bikes made out of plastic, then maybe I should get a bike made out of steel. Because I want to feel that hippy sentimentality about bikes I own.

About that time, my buddy Rick Hunter had an extra frame from a run of Wood Rats he had built, and so we haggled over a few things, and I got a new frame. It’s a freak of a bike. Old tech steel and hardtail but with a massive headtube and a 142×12 rear axle and super short 16.25 inch chainstays and 27.5 inch wheels and a 140 millimeter travel fork. And a lx11 drivetrain. And stupid wide handlebars. And a dropper post, dammit. It is built in such a way that weight conscious riders eyeball me nervously as if my perversion might be contagious. The frame probably weighs more than the frame and shock combined on my carbon full squish er. And I don’t care. It’s like the anti mullet bike. Business out back, party up front.

On our first ride, I looped it twice while trying to do wheelies. Bruised my tailbone. On our second ride, I wrecked while jumping a section of roots that I have never attempted to clear prior to that ride. Sprained my wrist. Next, I stuffed the front into the second jump of a double that I had also never before attempted to clear, my sprained wrist flailed off the bar, and I drilled myself through the top tube into the ground. I think I may be in love. This new wave throwback bike makes me feel young and dumb again (the dumb part probably never really left), and in spite of repeated attempts to maim me, makes me grin every time I go near it. This one’s a keeper.

I never found the perfect Sawzall/drill/flashlight/totebag pack, by the way. I left the hardware store that day with a 24 ounce waffle faced framing hammer and a double bit, 4 pound felling axe, and I laugh all Jack Nicholson in “The Shining” crazy like whenever I swing either of them. They’re keepers too.

The mountain biker’s field guide to douchebaggery

FOR ALL OF EARTH’S MAGNIFICENT CREATURES AND FRAGILE beauty, there sure are a lot of douchebags on this planet. They’re on the bus blaring bad music through phone speakers and sitting next to us on the plane scarfing a tuna salad sandwich with the lip smacking of a middle school make out session. They’re in our cubicle showing us a probably not contagious rash and coming up with a story that’s just like ours, only better. And unfortunately, they’re even riding bikes in the woods.

Sometimes I imagine a world where proprietors of douchebaggery are corralled on an island. Then again, I’d wager we’d all eventually end up on that island. We all have our moments of being ‘that guy’ due to obliviousness, an especially egocentric day, or good old fashioned social flubbing. Here’s a guide to avoiding jerkish behavior, whether it’s on the trails or reflected in the mirror.

The Mooch: Can I borrow your pump? Actually, I need a patch kit. You know, this would probably go better if I used a new tube. Got one? An experienced rider’s pack reads like a diary of trailside misfortune. With each mechanical, another item joins the quiver of tools and spare parts schlepped along on each ride like a clanky security blanket. We’ve carried food for two ever since that time one person’s bonking jeopardized the whole group. The duct tape, zip ties and pocketknife have MacGyvered us through broken shifters and unfortunately placed rips in our shorts. And yes, that is a tampon, because well be ready the next time a guy cores himself on an uncapped handlebar. But no matter how prepared we are, at some point well end up stranded on the trail, kicking ourselves for not having the one tool we need. Thankfully, there will be offers of help from nearly every passing rider. Benefitting from the generosity and preparedness of others are perks of mountain biking, but constantly relying on that kindness makes us douchebags.

The Stravasshole: The most important races often occur in solitude. The race to beat the storm. The race between coming in dead last and not finishing at all. The race to find out what we’re capable of when we stop being afraid to lose. There is nothing wrong with enjoying the thrill of digitally facilitated competition, but in the heat of the moment, when the taste of victory (or half digested bacon and Clif bars) fills our gasping mouths, temporary douchebaggery can occur. No matter how close we are to setting a record on that quarter mile stretch of singletrack, if we bump and grind and announce our desire to pass by barking “Track!” we shouldn’t be surprised if karma thwacks us right in the numbers.

The Hater: Suspension is for sissies! No wait. Gears are for sissies! Or maybe it was freewheels? We laud the awesomeness of our fixed gear 650b fatty by hating on your bicycle. Thankfully, the rest of the population isn’t missing out and doesn’t care.

The Dropper: When we invited the new guy on this ride, we did it with a smile, but we haven’t seen him in miles. When we saw him pushing up a hill we shouted, “Are you okay?” but might as well have asked, “Why aren’t you faster?” As he crested the climb, red faced and chewing back a vurp, we were already rolling out. Unless otherwise understood, inviting someone on a ride means we stay together. The break doesn’t start until they reach the top, and for the love of trail Gods everywhere, don’t ask if they’re okay while they’re pushing up a hill.

The One More Hill Douchebag: Six hours into a two hour ride, we promise the end is right after the next hill for the fourth time. We thought we were clear when we described the trail as “a bit of a grunt,” but now we’re scrambling to finish before dark and feeling guilty that your enjoyment (and endurance) waned long ago. We’re afraid revealing that we’re only halfway through will cause you to hate us, or worse, give up. No one wants to deliver bad news to someone who’s already on a death march, but we all deal with challenges in our own way. Playing down the length or difficulty of a ride can cause people to use energy they’d otherwise reserve and spur imaginary revenge plots even when there really is just one hill left. Our intentions may be pure, but being a nozzle about the ride’s length doesn’t make finishing it any easier.

The Mountain State Egotist: We grew up on mountain trails where a few thousand feet of elevation gain is standard. When a flat lander starts telling us about the trails in their state, we can’t help but utter a cocksure laugh before asking, “How can you mountain bike in a state with no mountains?” We assume any trails east of the Mississippi are flat and boring and, most annoyingly, far from good. Yet, when we talk about our favorite sections of trail, we refer to the swoopy ridgeline through the trees. One day, if we’re lucky, we’ll get to explore entire states filled with hundreds of miles of swoopy trails and not a single mountain in sight.

Inspector Gadget: We’re wearing headphones, a heart rate monitor and a GPS, which is probably why we can’t hear our brakes squealing. With cords coming out of our shirt, handlebar and pack, we ride in a cacophony of electronic beeps with intermittent stops for wooded conference calls and wire detangling. No doubt, technology’s safety leash and data enhanced toys can add to the trail experience, but only a chowder head lets their electronics distract so much that it detracts from another’s experience. We’d all do well to unplug the digital toys every once in a while and adjust our trickin’ brakes.

The Trail Troll: We ride when it’s muddy and don’t notice (or, worse, don’t care) when our empty gel packet falls from our shorts. We complain the trails aren’t hard enough for our special brand of bad assitude, and then ride around rock armoring and pass trail stewards without even a nod of thanks. It’s the lowest form of d bag who doesn’t look past their ride to see trails as shared resources made possible by communities of do gooders. Supporting those who support our trails, even if it means shutting up if we can’t help out, is the ultimate antidote to troll douche status.

The “Oh, it’s easy” Douchebag: With a Cheshire cat smile, we insist the tangled web of roots and rocks is easy. “Just go faster,” we instruct. “And stay off the brakes.” A few moments later, a cracked helmet and a mouth full of dirt prove that easy is relative and sometimes riding faster only makes people hit the ground faster. Next time, we’ll remember when tiny logs seemed insurmountable and riding roots was anything but easy.

The Always Has an Excuse Douchebag: We’re getting over a cold. And our brakes are dragging. And we probably shouldn’t have had that convenience store hotdog for breakfast. Sure, we might be riding slowly, but we’re totally, definitely, not normally slow. We’ve just forgotten that the only excuse necessary for riding slower than the rest of the group is, “I’m having fun.”

We all have our moments of forgetting tools or forgetting not to be a tool, but what’s important is avoiding a pattern of d bag behavior. So, lend a tube. Tell a new rider about that time we crashed on the same log. Pick up a piece of trash we didn’t drop. Thank the person in front of us for pulling over. Smile. Wave. Nod. Enjoy the ride. After all, it’s a pretty cool world out there, douchebags and all.


Some current sound efforts

Thermoacoustic projects are ongoing at various laboratories around the world, and some research teams have produced fully operational prototypes. For instance, a partnership between Denver’s Cryenco, a large-scale manufacturer of equipment for gas liquefaction and transportation, and LANL (funded in part by the U.S. Department of Energy) has developed a 40-hertz acoustic cooler for liquefying natural gas. This process requires lowering temperatures to near -250 [degrees] F. The conventional process involves large, expensive, nonportable equipment. By contrast, the acoustic cooler, which uses both thermoacoustic (heat-driven) and Stirling technologies, has no moving parts, no exotic materials, and no tight tolerances, making it extremely reliable and low cost. It is also much smaller, relatively portable, and well suited for low- and high-capacity systems.

The liquefaction process makes it easier to purify and transport natural gas, and it can also be applied to recover landfill gas, other biowaste gases, and gases that escape from oil wells and other facilities. Cryenco and LANL have proved the technology with a 100-plus gallons/day system, and they are working to develop a second-generation prototype liquefier that will burn about 20 percent of the gas (compared with 10-15 percent in conventional systems) to liquefy the other 80 percent, at a rate of about 10,000 gallons/day (a refrigeration power of about 140 kilowatts).

sound effect

The U.S. Navy has funded much of the thermoacoustics research in the United States. At NPS, scientists and engineers have made several thermoacoustic machines with innovative designs to support systems on the space shuttle Discovery and the warship USS Deyo. One of their significant contributions involves the resonator shape: By introducing certain changes in the cross section, they showed that shock waves characteristic of nonlinear systems can be suppressed, In building a prototype called TADTAR (thermoacoustically driven thermoacoustic refrigerator), a team led by Hofler used heat rather than electricity as the input power source, which was converted to acoustic energy. NPS has built some coolers that a large temperature drop, including temperatures below -150 [degrees] F.

Another group of researchers, at Pennsylvania State University, is led by Steven Garrett, who was originally at NPS. Garrett’s lab (funded in part by the U.S. Navy) is designing, fabricating, and testing refrigeration systems for military and commercial applications. It has produced operational prototypes that provide cooling capacities ranging from a few watts to hundreds of watts. One chiller called TRITON is designed to provide auxiliary cooling for Navy ships. It has a cooling capacity of three tons (about 10 kilowatts), meaning that it can convert three tons of water at 32 [degrees] F to ice at the same temperature in one day. Garrett expects this first-ever large-scale thermoacoustic cooler to have an efficiency within 30 percent of that of conventional systems (and become better in future generations) and to have comparable size and weight. The Penn State team has also built a solar-powered thermoacoustic engine that produces 120 decibels of sound, which may drive a thermoacoustic ice maker in the near future, and another unit that looks and operates much like a domestic refrigerator.

For my doctoral work at Purdue University, I have been working under the guidance of mechanical engineering professors James Braun and Luc Mongeau. Our research efforts have aimed at developing an optimizing design tool (software) and a low-cost prototype. This research seeks to validate modeling and to prove the technology for a light air conditioning system. While the current prototype has achieved some cooling, it is not yet fully operational.

The applications of thermoacoustics are being extended in various directions. At the University of Utah, systems have been built for use in cooling electronic microchips. Several other laboratories are working on innovative improvements to heat exchangers, electrodynamic drivers, and system configuration. They include research teams at Ford Motor Company, the University of Mississippi, and Johns Hopkins University.

Sound ideas

Is cooling by sound a sound idea? It’s certainly appealing for a variety of reasons. Besides being environmentally friendly, sound can be used to make a refrigerator with no moving parts, except perhaps for a moving coil and a piston or diaphragm vibrating at low amplitudes. No lubricants or sliding seals are required, promising high reliability. A significant performance advantage is that there is no on/off operation of a compressor–to lower the temperature, just “crank up the volume.” The pressure changes experienced in the system are actually quite a bit lower than those experienced in conventional vapor compression systems, helping reduce noise problems.

On the other hand, thermoacoustic systems have an important disadvantage relative to vapor compression systems: They typically require extra heat exchangers and a secondary fluid for heat transfer between the gas in the system and the air outside. Moreover, designing the driver, the stack, and the heat exchangers presents a number of nontrivial challenges. For instance, the electrical and mechanical characteristics of the driver must be “tuned” to cooperate well with the acoustic system. Garett’s team at Penn State, in conjunction with a company called CFIC Inc. (of Troy, New York), has developed a sophisticated driver at about 88 percent efficiency, but the prototype is still fairly expensive.
Computer models (verified in some cases) suggest that thermoacoustic systems can be made to operate efficiently and can be competitive in several markets, including domestic refrigeration. But these predictions have not yet been realized with the few existing prototypes. In addition, most prototypes have been costly and have involved incremental changes from previous systems. Because of the simplicity of these systems, however, it is reasonable to expect that when production moves to larger scales, they will become cost competitive with conventional systems.

Thermoacoustic technology is in its infancy, and the research monies spent to develop it are pennies compared with the amount spent on other refrigeration technologies. The investments already made in existing technologies tend to make industry more inclined to intensify efforts on current system improvements than to spend resources on new and uncertain technologies. The best opportunities for development therefore tend to come from new cooling ideas for niche markets.
How long will it be before thermoacoustics is commonly used in a commercial product? That is unclear, but it will likely take several years of significant research and development to bring the technology to the mainstream. It is a matter of obtaining adequate financial resources to develop the technology and, perhaps just as important, a matter of attracting talented people trained in a wide array of disciplines. While these are substantial hurdles, the potential of thermoacoustic technology suggests that not only can it help with existing cooling needs but it will probably offer solutions for cooling, heating, and energy-recovery applications yet to be identified.

Heating and Cooling Cycles

The technologies used in most of the world’s cooling machinery are based on cycles (called thermodynamic cycles) of heating and cooling what is called a “working fluid.” In each cycle, the fluid (which may be a gas or a liquid) undergoes several steps:(1) compression, which raises its pressure and temperament;(2) heat rejection (expulsion);(3) expansion, which lowers its pressure and temperature; and (4) heat uptake from the material to be cooled. Work is done on the fluid to make it move heat energy from a region at a lower temperature to one at a higher temperature.

When the system operates, the working fluid may either remain in the gaseous form or undergo phase changes (“vapor cycles”) from liquid to vapor to liquid again. In the latter case, the fluid is referred to as a refrigerant. During evaporation, the refrigerant absorbs heat; during condensation, it loses heat. An advantage of using refrigerants is that during phase changes, heat transfer occurs at constant temperature. Moreover, the energy transferred per unit mass of liquid is high. Such vapor cycles have long been employed in most domestic refrigeration and air-conditioning systems.
Conventional systems using gas as the working fluid include those that operate on what are called Brayton and Stirling cycles. (Modern Stirling systems include pulse-tube systems.) Thermoacoustic systems also use gas. Brayton cycles, which often use air as the working fluid, are employed in airplanes and modern European trains, where reliability and weight are more critical than cost and efficiency. Stirling system have been around for a long time and offer high efficiency by a high cost, and they have some reliability problems. They are widely used in low-temperature applications, such as gas liquefaction.

Stirling and thermoacoustic systems both use sound energy. But while the former use sound in the form of traveling waves (see main text) and require large piston displacements, the latter use standing waves and need only small (or no) piston displacements. The compression and expansion processes occur at near-constant temperature in Stirling systems but not in thermoacoustic systems. Brayton systems circulate all of the working fluid from cold to hot temperatures, so the fluid experiences large pressure changes, and expensive equipment is needed to achieve efficient compression and expansion processes. In thermoacoustic systems, each fluid element operates between temperature and pressure ratios that are much lower, making compression and expansion processes simpler and more efficient.
Brian L. Minner is a doctoral student in mechanical engineering at Purdue University. His field of research is thermoacoustics.

Sounds that cool spark hot ideas part 1

The developing technology of thermoacoustics is showing that sound energy offers a relatively simple and environmentally friendly means to drive refrigerators, air conditioners, and other cooling systems.
A sound system has been catching the ear of refrigeration people, physicists, engineers, and business people the world over. No, it’s not the stereo of the future. It’s a system that employs a loudspeaker to power a refrigerator. Based on an approach called thermoacoustic refrigeration, it makes use of the energy in sound waves to provide cooling.

Most of us rely on cooling systems to preserve food and to provide comfort control at work and at home, as well as in cars, planes, and trains. There are numerous other applications, ranging from cooling tiny computer chips to large, industrial machines. While these are important applications, there is concern that the already enormous energy demand for cooling purposes will only increase as nations raise their level of technological development. In addition, there is the concern that many established cooling systems operate, with refrigerants that, if leaked to the atmosphere, may contribute to ozone depletion and global warming.

In response to these concerns, new technologies that are both energy efficient and environmentally friendly are being sought. Impetus in this direction is also being driven by international bodies that have initiated agreements to phase out the production of refrigerants with high ozone-depletion potential (ODP). After the expenditure of hundreds of millions of dollars, new refrigerants have been found that have zero ODP, but they all have nonzero global-warming potential (GWP), suggesting that they, too, may be phased out in the future. A suitable new refrigerant must satisfy numerous additional criteria related to such factors as the temperatures desired, toxicity, flammability, materials compatibility, and cost. The list of potential refrigerants becomes very short when all these factors are considered, making it clear that other technologies should be explored.

In this light, the use of sound energy to drive cooling systems is attractive because it is inherently clean and simple, working with environmentally friendly fluids and materials (having zero ODP and zero GWP). A variety of prototypes have shown that this approach works in real systems, though typically not yet as well as computer models predict. One day, refrigerators, air conditioners, and ice chests might run on sound produced by electrical power or by heat from the sun.

Looking back

People first recorded their observations of naturally occurring thermoacoustic effects almost 150 years ago, when they noticed that a cool glass tube would often sing when brought in contact with a hot bulb This effect, wherein heat energy is converted to sound energy, is the reverse of a thermoacoustic cooling process. Researchers began investigating these effects in the 1960s, and a Swiss scientist, named Nicholas Rott developed most of the theory that is now used to model thermoacoustic systems.

The development of thermoacoustics for practical refrigeration began in the early 1980s at Los Alamos National Laboratory (LANL) in Los Alamos, New Mexico. The first carefully instrumented thermoacoustic cooler system was completed in 1985 as part of Tom Hofler’s doctoral work at the University of San Diego, with guidance from LANL researchers Gregory Swift and the late John Wheatley. It achieved temperatures near -80 [degrees] C (-112 [degrees] F).

Since then, several generations of prototypes have been built, including the first domestic refrigerator (in the early 1990s) at the Naval Postgraduate School (NPS) in Monterey, California. Each new prototype achieved some new performance targets and provided a wealth of information used in developing the next. At NPS, early efforts focused primarily on prototypes providing low-temperature, low-capacity cooling, while at LANL, much of the work involved making large, thermoacoustic engines, using heat to generate sound, and sound to generate electrical power [see “Cooling With Sound,” The World & I, September 1992, p. 292].

The development of thermoacoustics for commercial applications has accelerated since researchers at LANL made software available that performs calculations and predicts the behavior of thermoacoustic systems, enabling an increase in the number of newcomers participating in the field. Thermoacoustic refrigerators have been or are now being developed for a variety of purposes, such as cooling medical supplies, tropical fruit cargo, and seismic instruments in the earth’s crust, as well as for liquefying natural gas.

About sound

About 300 years ago, Newton surmised that the transmission of sound through a fluid was characterized by “pressure pulses” moving through particles of the fluid. He was right: Longitudinal pressure waves travel through an elastic medium at the speed of sound, jostling fluid elements back and forth (at fluctuating velocities much slower than the speed of sound) in the direction of the wave motion. (This differs from transverse waves in a string, where string motion is perpendicular to wave propagation.) The local changes in pressure, which are small compared with the total pressure in the fluid, lead to changes in local density and temperature, and these changes enable thermoacoustic phenomena.

There are different kinds of sound-wave fields. Waves that are confined to small spaces are reflected at the boundaries, leading to the formation of “standing” waves. On the other hand, if most of the sound energy is absorbed at the ends and reflection is negligible, the result is a “traveling” wave field. The timing (or “phasing”) between pressure fluctuations and displacement of fluid particles depends upon the type of wave. This phasing is important in systems that employ sound for useful thermodynamics. Thermoacoustic systems primarily employ standing waves, while conventional Stirling systems (see Heating and Cooling Cycles) employ the phasing of traveling waves.

Sound does not travel indefinitely–it dissipates. The dissipation is quickest near solid boundaries, because of(a) friction between fluid layers, and (b) heat transfer caused by temperature fluctuations of fluid elements next to the solid. In designing thermoacoustic systems, we seek to reduce sound dissipation by the former mechanism and to enhance it by the latter. Useful heat pumping can be done only near solid boundaries in thermoacoustic systems.

A simple thermoacoustic heat pump has an acoustic driver (loudspeaker-like power source) attached to one end of a rigid tube that is sealed at the other end. The tube, whose diameter varies along its length, contains (a) a stack of thin, parallel plates, which functions as a heat-pumping element, and (b) hot and cold heat exchangers, perhaps with finned tubes. The sealed tube also contains the working fluid, which is normally an inert gas such as helium or argon or their mixture. The gas is pressurized to about 300 pounds per square inch (20 atmospheres).

People often think they could solve some noise problems by putting such sounds to useful work. But thermoacoustic systems use pure tone (single-frequency) sound, often (but not always) around 200 hertz (near middle C). This tone is called the system resonance frequency–the frequency at which the response is highest for the given power input. If more tones are added, the performance degrades. The whole system acts as a resonator. By using damping techniques, however, the exterior noise level will be below that of conventional systems.

As the driver operates at the resonance frequency, it produces relatively large pressure fluctuations that oscillate the fluid back and forth. Only the fluid near the stack participates in the relevant thermoacoustic effects. Each acoustically driven set of fluid particles close to a surface in the stack undergoes a thermodynamic cycle (see sidebar), absorbing work while repeatedly mow ing a bundle of heat energy from a cooler location in the stack to a warmer location. When many gas particles contribute to the process, significant amounts of heat can be moved, making one side of the stack cold and the other side hot.

The thermoacoustic system described above has a fairly simple appearance, but designing a machine raises many questions. For instance, what should the frequency of sound in the pump be? What gas should be used, and at what pressure? What would be the best designs for the stack, the heat exchanger, and the container tube? How should the acoustic system interact with the mechanical and electrical systems of the driver? These and other questions have complicated answers. To design a useful system, computer modeling is required to figure out the many trade-offs.