APU with no space on the frame

Depends on what services you are wanting from the APU. A mini split or RV roof a/c operated off of lithium phosphate batteries can resolve temperature issues. If its battery charging while away doing hometime, then a solar panel on the dash kit with charger resolves that. Was there anything I didnt think of?

 

II keep getting Facebook ads for the HP2000 APU. Don't know anything about its reliability or cost, but it is compact based on the pictures.

Our fleet of newer gen volvos has just a typical Carrier APU behind the side fairing, but not sure the clearance difference and fuel tank size would matter too.

Here's the HP2000 though:

 

get smaller fuel tank to fit apu

 

I haven't posted pics because I still haven't mounted my outside unit but that's exactly what I've done. 560ah of lithium and a 2500 watt inverter under passenger side bunk and 9000 btu mini split. My truck already has a Webasto heater and factory inverter on the driver's side to handle heat and house needs.

The only thing I don't have is a coolant loop/block heater solution but I don't need it where I run. YMMV.

 

Depends on how creative you want to get and how much actual room you have. In many cases there is room to slide a fuel tank forward or you can remove the catwalk step. There is often room behind the ferrings you can use or you can as someone else recomended get a smaller fuel tank. You can directly mount them against the cab on the catwalk (this can be really loud though). RV ACs, battery powered mini splits and more.

Also some brands are much thinner then others. My green for example is a good 9 inches narrower then a comparable thermocant. I have even seen some guys cut their fender off and put a chunk of metal on the side of the APU and use the APU itself as a fender.

 

Lithium is definitely the way to go. Prices have come down considerably in just the last year. Epoch are now doing a 460AH heated battery for $2000. Guaranteed for 11 years too. Just put a dc to dc charger on to charge it. Pick up a roof mount 12v ac for under 3 grand.
Look at the van life crowd forums and you’ll get plenty of ideas.

 

If you're trying to save weight and increase space, why not just get a single 150 gallon tank on the driver side and free up the entire passenger rail? That's how our truck is set up, and we haven't run across any fuel problems running a team truck. It's also kind of nice not having to worry about the satellite pump every time we fuel.