An unseasonably cold Winter is forecast for the Northern part of the US. That barely seems like news but it does cause unease for what you can do to stay comfortable or to head off the pipes from freezing when the power goes off. An ice storm can hack down power lines and block roads for days at a time. Unluckily oil and gas heaters need air circulation fans to circulate heat around a house. Most also need electrical power to ignite the fuel. Depending on your own circumstances and where you live a Winter power outage can be anything from discomfort to disaster.

Portable Coleman heater are a cheap and convenient way to keep a Winter power outage from turning into a nasty experience. Portable gas heaters come in several different sizes of heating capacity, so how do you resolve how many heaters you may need, and what sizes to get?

Here’s a back of the envelope method for answering the question about what size portable heater you will want to have. Portable heaters are rated in BTU. To define how many BTU you need to warm an enclosed space to a functioning temperature you must first calculate the volume of the room in cubic feet. The formula for volume is L x W x H. That’s the Length of the room x the Width x the Height to the ceiling. As an example, an 8×10 room with an 8 foot ceiling has a volume of 640 cubic feet (10×8x8).Next multiply the volume calculation of the room by what we’ll call an arbitrary ‘insulation factor.’ The normal interior room has an insulation factor of 2. A badly insulated room has an insulation factor of 4. So for our 8×10 room you would need a portable gas heater that was rated between 1,280 BTU and 2,560 BTU depending on your guess at the room insulation and how warm you wanted to heat it. If you just want to keep room temperature above freezing then you could probably go with a factor of 1.

You can get propane in one lb. cylinders which are available everywhere and are easy to store. You can use the same propane cylinder to fuel a Coleman propane stove. If gasoline storage is not a problem a portable inverter gnerator would provide AC electricity for lights, TV and radio.