Ideas on Air Compressor , not the usual questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

El Campo · 09-07-2013, 08:01 PM

Recently bought a big (for me) Devilbiss compressor with an approx 200 gallon tank and a big pump on it. Now my other little cheap Homey depot 3.5 HP 80 gallon compressor shelled out on me before had chance to plumb in the big compressor. Thinking about running line into smaller tank and using it as an extra reservoir. What would be a good distance from the big compressor to do this? The big compressor turns slow (around 700 RPMS) if I remember correctly so it shouldn't build up too much heat the way that smaller high speed compressors do but would still think that the auxiliary tank (the 80 gallon) would assist in cooling the air possibly. Thoughts?

_Ogre · 09-08-2013, 01:10 PM

yes, the added tank will help cool the air

some of the heat is from friction of the compressor, most of the heat is from compressing the air.
even a slow rpm compressor will build heat and blister your skin if you touch the compressor head.
using the ideal gas law, PV=nRT is a ratio. as pressure increases and volume stays the same, therefor temperature increases (ignoring nR for now).
as you compress air, you concentrate the moisture in the compressed air. some of the water condenses in the tank.

as you use air thru a pressure regulator, using the same ideal gas law PV=nRT, pressure decreases, volume increases and temperature decreases.
it is this cooling at the regulator that condenses the water vapor in your water lines.

many compressors have a radiator in the line from the head to the tank with cooling fins and use the compressor pulley as a fan to get the heat out.
the next best thing is more radiator, the best radiator for a small shop is your steel or copper air lines.
run a sloped loop on the wall of your shop after the regulator to a drop with a drain valve.
then go to your main header in the shop, individual drops come out of the top of the header.
this should solve any water coming out at the drops.

this is a basic schematic of how i ran the air in our shop.
yes we have a refrigerated air drier, but most of the water is condensed out in the loop.

boy... am i a geek

El Campo · 09-08-2013, 01:19 PM

Wow great info here! I appreciate it!
Posted via Mobile Device

09-07-2013, 08:01 PM	#1
El Campo Registered User Join Date: Jul 2011 Location: El Campo, Tx Posts: 1,246	Ideas on Air Compressor , not the usual questions Recently bought a big (for me) Devilbiss compressor with an approx 200 gallon tank and a big pump on it. Now my other little cheap Homey depot 3.5 HP 80 gallon compressor shelled out on me before had chance to plumb in the big compressor. Thinking about running line into smaller tank and using it as an extra reservoir. What would be a good distance from the big compressor to do this? The big compressor turns slow (around 700 RPMS) if I remember correctly so it shouldn't build up too much heat the way that smaller high speed compressors do but would still think that the auxiliary tank (the 80 gallon) would assist in cooling the air possibly. Thoughts? __________________ 72 Chevy blue LWB, 99% original Oklahoma truck, 28,000 miles 72 Chevy SWB: http://67-72chevytrucks.com/vboard/s...d.php?t=486626 (Attempt/Mistake #2) 2003 Harley Davidson Dyna Superglide with 2007 Street Bob front end 2000 Ford F350 Powerstroke 4WD CCLB, 310,000 miles running great (STOLEN St. Patricks Day 2014 AND NEVER RECOVERED) 2002 Ford F250 Powerstroke 4WD CCLB (To replace stolen one) Hook em Horns!!!

09-08-2013, 01:10 PM	#2
_Ogre Registered User Join Date: Jan 2012 Location: Motown Posts: 7,677	Re: Ideas on Air Compressor , not the usual questions yes, the added tank will help cool the air some of the heat is from friction of the compressor, most of the heat is from compressing the air. even a slow rpm compressor will build heat and blister your skin if you touch the compressor head. using the ideal gas law, PV=nRT is a ratio. as pressure increases and volume stays the same, therefor temperature increases (ignoring nR for now). as you compress air, you concentrate the moisture in the compressed air. some of the water condenses in the tank. as you use air thru a pressure regulator, using the same ideal gas law PV=nRT, pressure decreases, volume increases and temperature decreases. it is this cooling at the regulator that condenses the water vapor in your water lines. many compressors have a radiator in the line from the head to the tank with cooling fins and use the compressor pulley as a fan to get the heat out. the next best thing is more radiator, the best radiator for a small shop is your steel or copper air lines. run a sloped loop on the wall of your shop after the regulator to a drop with a drain valve. then go to your main header in the shop, individual drops come out of the top of the header. this should solve any water coming out at the drops. this is a basic schematic of how i ran the air in our shop. yes we have a refrigerated air drier, but most of the water is condensed out in the loop. boy... am i a geek __________________ cool, an ogre smiley Ogre's 58 Truk build how to put your truck year and build thread into your signature shop air compressor timer

09-08-2013, 01:19 PM	#3
El Campo Registered User Join Date: Jul 2011 Location: El Campo, Tx Posts: 1,246	Re: Ideas on Air Compressor , not the usual questions Wow great info here! I appreciate it! Posted via Mobile Device __________________ 72 Chevy blue LWB, 99% original Oklahoma truck, 28,000 miles 72 Chevy SWB: http://67-72chevytrucks.com/vboard/s...d.php?t=486626 (Attempt/Mistake #2) 2003 Harley Davidson Dyna Superglide with 2007 Street Bob front end 2000 Ford F350 Powerstroke 4WD CCLB, 310,000 miles running great (STOLEN St. Patricks Day 2014 AND NEVER RECOVERED) 2002 Ford F250 Powerstroke 4WD CCLB (To replace stolen one) Hook em Horns!!!



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