I am discovering this year that my furnace actually runs very well and is actually pretty efficient. The problem is NOT with the furnace. The problem is with all the duct work running under the floor. From my furnace I have 3 runs of duct work. None of it is insulated. I suppose it's designed that way so heat will go to the underbelly, thus qualifying the camper to have an "Arctic Package".
Since we have no water in the camper after winterizing, there is no need for a heated underbelly. This year, I decided to pull the one of the ducts directly off the furnace and just let it blow from there. I can do this with the way my furnace is installed.
By removing only 1 duct, and letting one line blow directly into the middle of the body, the difference in how much the furnace is running is unbelievable! It so much less. (we are still using our camper in the drive way at home every day and sleeping in it every night).
I'm off work all next week(Thanksgiving), and am planning on doing some DIY remodeling of the furnace area, to turn the furnace from a ducted system to a central system by cutting a new return hole, and separating old return to become a new forced air - out, and simply removing the existing ducts right at the furnace. So, if we want, I can reconnect the the original ducts back to the furnace any time.
As far as the front bedroom? (this is the line I unhooked), it stays warm with no problem. Actually, it stays warmer with the central air now, than it did when air was coming through the duct in that room. We don't like it so hot at night in the bed room area anyway, but even with that line disconnected, the bed room was warmer than with that line connected. THAT's how much heat loss is going into the underbelly!
I suggest before you invest in a new heating system, that you re-negotiate your existing furnace. Close off, or reconfigure your duct work system, and try to divert heat from going to places you really do not need heated. You'll be surprised at how well your on-board furnace actually does work.
