Electric space heaters are cheap, clean, portable and can be an excellent choice for supplemental heat; of course, they will not help during a power outage. When selecting an electric heater, be certain your home's electrical system will handle the additional load. Many older homes are inadequately wired and the use of one or more electric heaters may cause a fire hazard.

    There are three main heat sources that do not require electricity: wood stoves, portable kerosene heaters and unvented gas heaters. All three can be used as both supplemental and emergency heat systems. Let’s look at some of the advantages and disadvantages of each.

    Wood is a readily available fuel on most farms but for urban residents, firewood can be a significant expense. A wood stove requires a good chimney. If you already have one, stove installation is fairly economical. If chimney installation or repair is required, the cost goes up sharply. Wood stoves are somewhat difficult to regulate and require regular loading. There is also a certain amount of mess in the house from carrying the wood in and the ashes out.

    Unvented portable kerosene heaters have been popular for several years. They provide considerable heat from a small unit, can be moved from room to room and there is no cost of installation. They produce a radiant heat and work best when set near the center of an open room.

    On the negative side, they require regular fueling and you must have proper storage for several gallons of fuel. You must allow the heater to cool down before refueling and spilled fuel is a potential hazard. 

    Kerosene heaters are an unvented flame and they deplete oxygen from the air and produce waste gasses, even when operating properly. In most older homes, there is enough air infiltration to keep this from being a problem, but extra ventilation may be required in a tight, well insulated home. Proper maintenance of the heater is very important for efficient, clean burning.

    Unvented gas heaters have gained popularity in the last few years. They produce a large amount of heat from a small package. Installation is cheap and easy; they can be wall mounted or set on the floor anywhere that a gas line can be run. Hooking to a natural gas line or a large propane tank eliminates the problem of refueling.

    Some of these heaters have an electric fan to provide better air circulation through a larger area. The fan is not required for operation, however, so the unit can still be used during an electric outage. These heaters work best in a home with a fairly open layout to allow for heat circulation.

    As with the kerosene heaters, the flame depletes oxygen and produces potentially dangerous waste gasses. In addition, the potential exists for a gas leak. Always follow the manufacturer’s recommendations.

    Any of the above heaters can be used safely and effectively for supplemental or emergency heat. In all cases, the house should be equipped with smoke detectors and carbon monoxide detectors to provide you with early warning of a dangerous situation.