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Old 07-22-2010, 06:42 PM   #225
Ran D. St. Clair
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Join Date: Apr 2009
Posts: 212
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To sleep, perchance to dream…

As with every other part of the truck, when completed it gets tested, so I have been testing the bunk beds most every night for the last week or so.

I was getting a little cold just before dawn, so I invested in a 12V heated mattress pad for $89.95

http://cozywinters.com/shop/ew-rvhmp.html

So far it works great. I wanted the heat down towards the foot end of the bed but it isn’t quite long enough to cover the twin mattress from foot to head, and the head end has heavy input wires that run the width of the mattress pad. I didn’t want those wires running under my shoulders, so I flipped it and put the head end of the pad at the foot of the bed. Since there are no heating element wires in the last 4” of the pad on that end I attached the pad to the ribbing on the bottom side of the mattress. That way the pad wraps around the foot end of the mattress and the heavy wires are between the bed frame and the mattress, not under my feet. Turning the pad head to foot forced me to extend the wire between the controller and the pad with some lamp cord, but that was no problem. I can solder and I have shrink tubing. I also replaced the cigarette lighter style connector with an Anderson Power Pole connector to match the outlets in my truck.

The instructions warn that it must be pinned to the mattress so it can’t bunch up and overheat. They provide large safety pins (like the kind you would use for a cloth diaper). I pinned it to the heavy ribbing at the edges of the mattress, not directly to the thinner areas of the mattress cover. It stays nice and flat that way. I can’t feel the top edge of the pad under my shoulders, or any hint of the heating wires inside. It feels like any other mattress pad.

It doesn’t get super hot like some 110V AC units but it does get warm enough to do the job. I like the energy efficiency of producing heat under the covers where it can keep me warm without heating the whole truck. I also like not being buried under a heavy pile of blankets. If you want to get into a nice warm bed, you need to turn it on full blast 30 minutes early though. It only draws about 6A when running flat out so that’s only 72W.

The heated mattress pad comes with a thermostatic controller, which is to say it has a single knob like most simple electric blankets. It doesn’t regulate the temperature of the mattress pad but it does provide more heat to the pad when the controller is in a cold environment and less heat when the controller is warm. This is the standard mode of operation for most electric blankets. It all works fine, but there is no light or led to remind you that it is on (or off) and you can’t see the numbers in the dark. I haven’t found this to be a problem though. The knob has progressive tension as it is turned on and you can literally feel how far it is on. Also, it has a very broad range of adjustment so I have not had any difficulty finding a comfortable setting even in the dark.

After a couple of nights I decided that the foam mattress I bought was just too firm, so I picked up a piece of 1½” memory foam and slipped it under the heated mattress pad. I also added a regular mattress pad on top of that to help protect the heated mattress pad and keep it clean. Also the heated mattress pad doesn’t have a full fitted skirt to contain the memory foam but the regular mattress pad does. The memory foam seems to have solved my problem and it is now in a range that I can live with.

Making the bed is still a bit of a pain, but I am figuring it out. At this point I am just jamming the bedding in between the mattress and the bed frame, which mostly means between the mattress and the wall. It seems to stay pinned there nicely, so I only have to make the bed when changing the bedding. I don’t tend to mess up the bedding when I sleep, though I know some people do.

I did go out and buy a bunch more sheets and blankets. I figure I need at least 4 sets of bedding so I can have 2 on the bunk beds and 2 available to be washed. I haven’t bought a heated mattress pad for the top bunk yet.

For the moment, the Platinum Cat catalytic propane heater isn’t installed yet. The truck is very well insulated, and once the heater is installed I may not even need a heated mattress pad. I do like the idea of being able to turn everything off at night though, at least everything but the heated mattress pad.

It does get very dark inside the truck at night. I have no windows and the only light that comes in is through the fan vent cover. Fortunately I like it dark. Pitch black is fine by me. I get plenty of light in the morning to let me know that the sun is up, almost too much for napping during the day.

I have noticed that the refrigerator is a bit loud. It’s not the compressor. It hums away pretty much as you would expect. It seems to be the boiling of the liquid in the evaporator that is making all the noise. It has an on again off again quality every few seconds that is annoying. I may have to give the folks at Sunfrost a call and ask if this is normal. It’s nothing I can’t get used to, but it is unexpected. I don’t remember it being this loud when I tested the fridge after I first got it. Then again things tend to seem louder when it is otherwise very quiet.

To be continued….
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