Our last post about heat, or lack of, got a lot of comments. I started to write a reply comment, but decided to just make it a post. All of the suggestions we received were pretty good, but...
We weigh 7600lbs on a 7000 trailer, so things that add weight are pretty much out. Also, while we love our location, it isn't necessarily permanent, so a trombe wall is out.
Our tiny house is pretty well sealed up. This is good. It means we don't have drafts. And that means we stay warmer. But it also means that using a wood stove would be a problem. Wood stoves suck air for combustion from there surrounding area. In a house with a bit of a draft and a lot of volume this is ok. In a well sealed tiny house, believe it or not, the stove would draw the oxygen out of your breathable air faster than new air would come in. So, you'd have to keep a window open when using it. And that might not be bad, but it might offset some of the gains of using it. A wood stove is also heavy and requires a lot of space around it. I'm not knocking wood stoves. I love them. But in this kind of small mobile space keep the trade offs in mind before installing one.
Refrigerators are another example of a small space fighting to hold its temperature against a larger space. Eventually, if the refrig is unplugged, the inside temperature will match the outside temperature. So you have to run the compressor to maintain the temperature. And we have to run our little heater to maintain our warmth. And actually, with our little stove we can get it up to 65 to 70 degrees, so it is ok. We just have to run it more than we thought.
I think one of the things Arlene wants to communicate is that if you are thinking of building a tiny house, be aware that it might not hold onto the heat as well as you might think. You do have to run the heater. Yeah, you could add more insulation, just be aware of what that might mean in terms of cost and weight and such. If you are in a very cold area, it is probably worth it to add a bit more insulation than we have. But up here we only have a few months of cold a year, and it isn't as cold as, say, Minnesota or Calgary.
In terms of heating, since September we have gone through one 5 gallon bottle of propane and are on the second. I figure that isn't too bad.