I don't know what they're mostly using. I used a window mount $150 A/C mounted in a cabinet and then made some metal ducting along with a waterproof door so it would be sealed when not in use. Cheap. Efficient. Clean install and no extruding AC to cause more drag. I'd guess that's probably the most common setup for teardrops.

Here's how mine is. The picture was partially finished interior. But you can see where it lives. On window mounts it's pretty easy to modify the ducting behind it with normal HVAC ducting to vend to the outside cleanly so you draw in fresh air and exhaust the hot air.

I don't have a heater in mine. Never really had a need for it. It's small and insulated. But the AC in the southwest is pretty great.



The hatch panel door you see to the right of the entry door is where my ducts enter/exit for the AC. Most campers just use a louvered vent cover. But I go offroad in dusty conditions a lot and I like to keep it sealed when not in use. So I used an o-ring sealed door (hatch cover) and then have the vent grille inside of that. The only issue run into is if I forget to open the door. Then it just recirculates the hot air and doesn't work. But it doesn't seem to overheat or anything. One other bonus of the small window mount style is that it draws roughly 7amps at startup on 120v or 850 watts. So it runs well on a 1000 watt (2000 peak) inverter and I can run on my batteries for a few hours if necessary.



The other great idea I've seen if it's a small teardrop is to just carry a 10x10 instant up canopy. Put it over top of the camper when you park it - instant shade and keeps the camper much cooler.