I am looking for a convection heater around 5000 BTU or so with a gallon or larger tank. I'm looking for something to keep pipes from freezing, or to heat a single room, that can run for a LONG time witthout needing refueled, and something that would be small and light weight. Are there any modern heaters like this? I know of 10,000 or so BTU radiant designs, but I'm looking for something smaller, that is convection (because I find the radiants to have a bit more smell during running, and they take quite a bit longer to GET to a low smell state). I do like the designs that have the removable fuel tank, that would be a plus, but if it has a 24hr or so run time that shouldn't be too big of a deal.