Elevations affect on Air Blast
What effect, if any, would geographical elevation have on Air Blast and what are some considerations to keep in mind?
There are four factors to consider when understanding the effects of altitude on air compression:
1. Air density- the amount of gas particles at sea level, per cubic foot, is higher than in an area such as Denver, Colorado.
2. Air pressure- also known as atmospheric pressure. The higher altitude locations have less gas particles (less density) pushing down on you, so this causes less atmospheric pressure. When flying you notice your ears popping as your elevation increases. At sea level the air pressure is 14.7 PSi, and at 5,000 ft. (Denver) the air pressure goes down to 12.1 PSi. That's an 18% reduction!
3. Air compression- because the air has less gas particles in it at higher elevations, the compressor struggles to give you the same amount of air at the higher pressures required to do air abrasive blasting.
4. Engine power reduction- engine horsepower is reduced by less air density, and can amount to a 20% reduction of power at 5,000 ft. Reduced engine power can result in the engine bogging down causing the RPMs to go down. This results in fewer compression cycles per minute, and therefore less compressed air output. Often the air compressor manufacturers can help with this by increasing RPM's of the compressor module by changing belts and pulleys, or adjusting on-board control computers to give the desired amount of air compressions to match output requirements.
Needless to say this can be a challenge, with a possible air pressure/volume disadvantage. By understanding this higher elevation issue, one can manage to overcome it by using the right air compressor that is set up to compensate for job conditions.