The pacbrake backs up some of the heat while the engine idles, thus its faster to warm up... Understand that when your driving down the road going down hill and the brake is on... it will back up some heat... but we've not noticed that on a gauge... there is so much air moving through the engine compartment at 50 mph that it just takes it away...
The air compress we offer is a volt air I think its called... . its as large as a compressor as what you might see on a class 7 or 8 truck... . will supply 5 or so CFM at 120 psi, cuts on at 120 or below and cuts out at 150... . uses cables about the size of battery cables on a small car... . and can draw up to 90 amps just before it shuts down... it will run a 1/2" air wrench and is about 10 in deep, by 18 wide and 18 tall. . fits nice in front of the wheel well and can be bolted to the floor... . sells for 895 I think and we've sold many of these to farmers for field use. . a switch on the dash turns it on or off and it has a cycle pressure switch... .
We don't use this on our trucks. . our trucks have the stock pacbrake, tank, air horns, and air bags... . with controls. . I think that answers all the questions...
Jim