Air compression causes weather, also helps preserve vehicle tires

By Rudi Kiefer

Weather Wise

Most of what we call weather is caused by the compression and decompression of air.

An electric air compressor doesn't give all of nature's powers, but it has a lot of neat uses.

For example, it'll help save gas, providing financial relief and conserving resources as well as reducing air pollution.

The objective is to keep tire pressure at the proper level.

Anyone who has played with bicycles likely is familiar with the tough pedaling feel of underinflated tires.

A few pounds per square inch, or psi, added to the tires, and the bike rolls much easier again.

Automotive tires are sensitive to this also, with a great increase in what's called rolling resistance when they don't have enough air.

Having an air compressor, even an inexpensive one, makes it a cinch to maintain tires properly.

The side wall of each tire has the proper pressure printed on it, commonly 35 psi for cars.

It doesn't hurt to keep it at the maximum level listed.

But letting it go down to about 28 psi has been estimated to cause between 10 percent and 20 percent increase in rolling resistance.

This will happen if the tires are left unattended for a few months.

Rolling resistance is commonly assumed to average about 20 percent of the overall force needed to propel a vehicle.

Consequently, a small amount of underinflation like the example above causes 2 percent to 4 percent drop in fuel economy.

If driving an average car 15,000 miles annually, checking tire pressure weekly can save $50 to $100 per year.

That's in addition to longer tire life and a safer handling car.

But the air compressor also is handy for many other chores.

If we run into a gas shortage and a water shortage at the same time (think 2005), we won't be allowed to wash cars and other things with the garden hose.

In that case, compressed air is handy for blowing dust off a car, bike and garage floor.

Air-powered tools are preferable over electrical ones if working outside when it starts to rain.

There are no cables that can short out in wet conditions, and the raw power of air tools is surprising at first.

How much punch they pack depends on the flow rating of the air compressor.

A large shop unit will be happy with small jobs, such as inflating the kids' pool toys. A small one, however, can't run a large tool.

So compare the cubic feet per minute, or cfm, ratings on the compressors and tools.

An impact wrench, great for opening wheel lug nuts, may draw only 3 cfm.

But a grinder that runs for longer periods needs four times that.

Tires can be inflated with almost any unit.

If there's an alternative, though, don't place a compressor next to car wheels in the garage.

Many electrical motors put out small amounts of ozone that can make rubber tires deteriorate when ozone accumulates nearby.

Source : http://www.gainesvilletimes.com/news/stories/20070624/localnews/181225.shtml