[ATeam]

All sleeper manufacturers will tell you how well their units are insulated. I don't know of one that will say theirs is poorly insulated. One thing to look at is the floor. ARI puts three inches of insulation in the floor, which is thicker than some.

The manufacturing process is different than some too. I don't recall the name that describes ARI's floor manufacturing process. The end result is an air-tight, pressure tested, leak proof floor. If you tour a sleeper manufacturer's plant, ask to see how the floors are made.

The Onan generator with roof unit setup is commonly used on RVs and RV trailers. They have way more space to heat and cool than a truck sleeper (multiple roof units are used on large RVs). Using the same setup on a truck sleeper, even a large one, provides plenty of reserve capacity. Also nice about that setup is the roof unit needs only power from the generator to work. It is otherwise a self-contained system that can be easily removed and replaced if it craps out.

We paid just over $1,000 for the roof unit brand new. Most any RV dealer can work on it. But at that price, it may be easier to simply pop a new one in if the old one fails.

When I read of things like generator refrigerant leaks, temperature control electronics that are not working but are not properly diagnosed, repeated trips to dealers to fix the same problem, and four-figure repair bills, splitting the functions seems to make more and more sense.

Use the generator to do one thing; generate electricity. Use the roof unit to heat and cool the sleeper. For truck engine warming in the winter, the generator can power an electric block heater and oil pan heater. For truck battery charging, both types of generators work the same way.

With components dedicated to specific functions, if a heating, cooling or temperature control (electronics) issue develops, the worst case is you will have to replace the entire roof unit at a reasonable cost. Plus, you will know for sure the problem is fixed because the entire unit is brand new.

For generator service and repairs, Onan dealers are easy to find. Most of them have been working on Onan generators on large RVs for years. They know their products and are pleasant to deal with.