moonlightrunner wrote:
Gdetrailer wrote:
... there is no free lunch (or heat)...
Solar heat collectors come close. I mocked up Mother Earth News' Heat Grabber and it worked pretty good. I modified the Heat Grabber for Apartments to fit an RV window. Maybe over the summer I will build one that I can transport.
Solar AIR collectors only work during the day and provided there is not a lot of cloud cover. Doesn't help at all during NIGHT TIME when it is coldest. STRIKE ONE.
Solar WATER collectors can work during the night, PROVIDED you have enough collectors AND sufficient "storage medium" to store several days worth of collected heat. For a RV you most likely would need several HUNDRED GALLONS of liquid storage and an extremely well insulated tank and would want to use antifreeze so your system doesn't get damaged by freezing. You most likely would need to pump the liquids useing electricity in the process since gravity systems can be a bear to get working unless everything is perfectly level and plumb. Extremely heavy and bulky to make portable not to mention expensive even as DIY "project" you will easily spend several thousand in materials alone. STRIKE TWOOOO...
I personally think if you really want to camp in the winter time that you SHOULD be willing to spend some money on the heating portion and do so with the proper equipment instead of attempting to invent half baked ideas which have a very great possibility of buring down your RV or killing you with CO poisoning.
RVs do not have sufficient INSULATION, you have walls which are 1 1/2 inches thick often with 1" bat of fiberglass insulation, no vapor barrier. That insulation value is about R3, maybe R3.5 with high performance fiberglass (RV manufactures tend to use the cheaper lower cost fiberglass).
The roof is no better with 4 inches in the middle tapering down to 3/4" at the ends, average at best you might have R3 to R3.5 there.
The floor, well once again you have 1 1/2 space under the floor but instead of better higher performance of fiberglass they use low R polystyrene foam. For that space you are looking at R2-R3.
Most RVs use single pane windows which have less than R1 insulation and the doors and windows use aluminum frames with no thermal break. You have in effect ZERO R value there.
Put all the numbers together and your typical RV has a R value of 1-1.5 IF you are "lucky". A RV is nothing more than a "wind break".
My suggestion is instead of trying to create a bunch of half baked heating ideas perhaps try ADDING insulation, rework the windows and doors. These things will pay off big time.
Basically remove the outside skin and ROOF, FIR OUT the walls, add at least 1 1/2 inches to the walls and three inches to the roof. Then remove existing insulation and have professional spray foam sprayed into all the walls and ceiling. Then underside add firring under there and have it spray foamed.
Double pane windows and creating a thermal break for the doors and windows and now you have a RV that has the potential of R10-R15 and heating that will use considerable less energy to heat..
When I rebuilt my TT I used 1" Poly Iso (R7) and 1/4" (R of 1/2) foam (used under siding)and I can tell you this, turn off the heater and in several hrs the trailer is the same temp as the outside which is an improvement over the old R3 fiberglass which was less than 20 minutes...
