I have a couple or three of those kerosene heaters like JW is using. I use them for emergency heat if a natural gas furnace goes out in an apartment until I can get it repaired if the electric circuits are not up to the task of electric heat. I also use them about once or twice a year when the temperatures in my area fall below zero for extended periods for overnight heating in basements to prevent frozen pipes. I have never been able to get rid of that kerosene odor, and I would not want that in my house or an apartment longer than necessary. There is less soot and odor with a smaller flame, but the heat output over all is lower as well and I have never tried to measure the efficiency of heat out vs. fuel consumption. I would find it difficult to believe that it is healthy to breath in the products of incomplete combustion which always seem to be present to some extent. Here the kerosene is rather expensive. It is cheaper at gas stations and pricey at home improvement or hardware stores, but I don't think it can compare with natural gas in my area on price. I paid about $50 per 5 gallons or so this year from a store when needed some. Electricity is three times as expensive as natural gas here by unit of energy, so kerosene might have a chance there, but I don't generally use electricity for heat except in my home where my solar and re dumps to electric heat in the winter, or in an emergency in an apartment if a furnace goes out. I keep a stock of 1500 Watt heaters for such occurrences though.
I have a supply of used olive oil, maybe 50 gallons or so, but I have never been able to get it to burn successfully through a wick, even with cooking it dry prior to use, so I never bothered to try it with the kerosene heaters. I thought about making biodiesel and trying that, but after this thread I am thinking that would be a waste. In the vegetable oil form it will keep for a long time so eventually I will find a use.
