Pony Pack , AKA APUs by REX , are the worst pieces of Junk know to man. I know . I have one. I'll be happy to sell it to you . Make an offer ! Can't wait to get the dang Boat Anchor off my truck , and a Real APU on it. For what I've spent on in , in 2 years , I coulda bought a TriPac , and taken the wife on a two week vacation.
I know I'm partial to TriPacs, but they are absolutely great! They freeze you out in summer, and burn you out in winter. They are by far the quietest APUs around. I had a Carrier, and it was good, but not as good as TriPac! And they are undoubtedly noisier than TriPacs, also Rigmasters and Dynasys are really, obnoxiously loud. Go with TriPac- you won't regret it!
I owned a proheat/carrier unit. It served me but was noisy, required a lot of hands-on maintenance, the AC was not effective, the heater burned out early on. The generator part lasted me 3 years of constant use. I would definitely go with a Tri-pac if I had to do it again. Forget about any other type due to the limited service network. If you go with a carrier, you'll likely be thinking of going with a roof-mounted AC powered by the Carrier generator. Tri-Pac is very quiet and for that reason alone - never mind the other positive reasons - it is THE one to get. The little motor was very good on the carrier but the tri-pac motor is also excellent. Cheap solution: for summer heat a $100, 5000 btu window unit in the passenger window works well. I used an Idle-Aire template, cut the round hole out to a rectangular hole to fit the window unit and used duct tape for the rounded gap at the top. If you have space below the bunk, the window unit can be stored there - it is as easy to set up as an Idle-Aire head was. This can be powered by: a small portable gas generator or by a ProHeat/Carrier APU whose A/C system has failed. Other power sources can be used since a 5000 btu unit is low power draw. This requires no hole-cutting on the truck and no permanent or intrusive changes. For the guy sitting at a trade show, just stick the window unit in, and run an extension cord into the facility if you can. Total cost to you for this is probably less than $175.00.
Bought a HP 2000 in august and would not advise anyone else to do so.Have had nothing but problems from day one and the service for warranty work is very poor.Have had to go get mine repaired after every trip out and at times would be defective leaving the shop.Mine broke down after 1 hour of being installed,and the first week the exhaust system fell off,it overheats,has a/c problems ,fails to start all the time it is not reliable at all Buyer beware is all I have to say and do your homework on this thing.And good luck getting someone to work on it.