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BurbMan's avatar
BurbMan
Explorer II
Jan 12, 2015

UPDATE: UnderBed Insulation

We are on an unplanned camping trip, boondocking for 10 days in Southern KY. We got down here on Friday, it went to 10* at night and the queen bed was like sleeping on a skating rink. Needless to say the Queen wasn't happy....

Like most TT's we have a front queen bed with storage underneath and pass-through hatches on either side of the TT. The problem is that there is no heat going into this space, and those thin access doors don't insulate much. So the cold underneath the bed sucks the heat out of the plywood platform and in turn the mattress. We upgraded to a foam mattress when we bought the TT years ago, and while it insulates more than the cheap-o they give you with the TT, it's no match for cold weather.

After doing some research, I decided to add some insulation to the underbed compartment. The frame that supports the bed platform is 1x1 aluminum with thin veneer wood glued to the outside. I found some 3/4" thick styrofoam panels in the local Lowe's and cut to fit. That should stop so much heat transfer from the sides into the unheated space under the bed.



Next we the bed platform itself. The underside of the bed has 2x2 spars for strength:



I got a roll of Reflectix at Lowe's and stapled that across the spars under the bed platform. This creates an insulating air buffer and should keep the bed platform warmer.



Anybody do anything like this? I did this mod this afternoon, and now that it's dark and temps are dropping, the bed seems warmer already. Remains to be seen what if anything this does in the summer.

20 Replies

  • I'll say right off that you did a much better job trimming that foam that I could ever do. I would go a step further though and put foam between the reflectix and the bottom of the bed. You can use small carriage bolts through the bed platform and some washers and nuts under the foam to hold it up.

    I second the idea of the 12 volt heated mattress pad instead of an electric blanket. Link

    Oh and we want to know how well your first insulation job worked.
  • Hi BurbMan,

    I'd go 12 volt with something like this: amazon That was just the first one I found. Draw is about 7 amps. Use it to warm up the bed, then turn it off. It may have a timer built in.

    I agree 100% with not running a generator while sleeping. It is far too dangerous to do.

    BurbMan wrote:
    Don, no shore power, only the Honda 2000 which I don't want to run at night....we're still on the same trip I posted here.

    The 2 6v batteries go to bed at 100% and wake up at 60% after the furnace is done with them....I do have a 150 PSW inverter that powers an outlet by the bed and we talked about looking for an electric blanket or such...any good links on where to buy one?
  • BurbMan wrote:

    I debated putting the Reflectix between the matress and plywood vs under the plywood....decided underneath would be better, would is pay to add another piece?


    If you can live with a higher mattress, I believe that you would get more value for your dollar by putting foam under the mattress rather than Reflectix. Reflectix used like this (between two other surfaces) is only R1 (+ any reduction of convection....which can be eliminated with simple plastic sheeting). I think the main area to look at is where the bed is hinged as this would be difficult to seal from underneath.

    Keep in mind that battery capacity is reduced at cold temps. At 10 degrees, your battery capacity is only about 75% of what it is at 77 degrees. Of course, during just a night or two, the battery internal temp won't get this low, but it will still be reduced somewhat. Regardless, I wouldn't advise trying to add the load of a heated mattress pad to your batteries unless doing so allows you to significantly reduce your furnace run time.

    Keep warm,
    Steve
  • I added 1 inch thick insulation under our mattress, and packed insulation and sleeping bags against the inside of those access doors.
  • Don, no shore power, only the Honda 2000 which I don't want to run at night....we're still on the same trip I posted here.

    The 2 6v batteries go to bed at 100% and wake up at 60% after the furnace is done with them....I do have a 150 PSW inverter that powers an outlet by the bed and we talked about looking for an electric blanket or such...any good links on where to buy one?
  • Hi,

    If there is 120 volt shore power I'd use an electric mattress pad.
  • I was in a very cold area recently. It helped a lot to put the reflectics on the windows. Turn it up to 70-72 in there and keep changing the propane tanks. Now is no time to conserve!
  • I need to add some launn to protect that foam when we get home...these are on-the-road mods right now!

    I debated putting the Reflectix between the matress and plywood vs under the plywood....decided underneath would be better, would is pay to add another piece?
  • I did similar. But perhaps overdid it a bit......

    I added 3/4" insulation to the entire under-bed storage area (the front curved wall, the sides, and the ceiling of the pass-through area. I then sealed all openings (two electrical outlets that really leaked air) with spray foam and then covered it all with plastic and luan (to protect the foam from damage). Under the bed platform, I added 1" foil faced foam (but no luan as I didn't want to add that weight to the lift arms) and then insulated where the platform sets on the frame with camper seal foam to reduce air infiltration there. Lastly, I put a piece of 4' wide Reflectix between the mattress and the platform (foam would have been better, but I didn't want the bed to get any higher).

    At ~ zero outdoor temps, I noticed the bed was much more comfortable.

    Steve
  • We did the Styrofoam on the side and the bottom of the bed...and yes ours "seems" warmer also!