Very cold weather is forecast for the Northern part of the US. That scarcely seems like news but it does cause unease for what you can do to stay tepid or to prevent the pipes from freezing when the power goes out. An ice storm can hack down power lines and obstruct roads for days at a time. Even oil and gas heaters need air circulation fans to circulate heat around a house. Most also need the power grid to ignite the fuel. Depending on your personal circumstances and what temperature zone a Winter power outage can be anything from discomfort to disastrous.

Portable Coleman heater are a cheap and convenient way to keep a Winter power outage from turning into a disaster scenario. Portable gas heaters come in several different sizes of heat output capability, so how do you determine 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 may need. Portable heaters are rated in BTU. To figure out how many BTU you need to heat an enclosed space to a livable 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 x 8 x .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 poorly 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 estimate of the insulation factor and how warm you wanted to heat it. If you just want to keep pipes from freezing then you could probably go with a factor of 1.

You can get propane in one pound cylinders which are available almost 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 camping generator would provide AC electricity for lights, TV and radio.