One Big Heater, or Two Smaller Heaters: Calculating Electric Heater Efficiency

There are several easy ways, when purchasing heaters, to mathematically calculate how many watts it will take to heat up a room as well as plenty of online sites with calculators that are fairly easy to use. This information is your first step when looking for an efficient electric heater. Before figuring this out you will want to determine other information, besides the overall size of the room that needs to be heated.  For example, you will need to take into consideration how high the ceilings are, how well insulated your home is and how many windows are in the room when deciding on electric heater efficiency.

The first step is to take a look at the room you want to install a heater in and see how much insulation it has.  If your room has little or no insulation, you should figure 15 watts of heat per square foot. This would apply for rooms such as a garage where there is usually little insulation, or many rooms in older style housing. If you do have some built in insulation, but would not consider the room to be very well insulated you should allow about 12 watts of heat per square foot.  A well insulated room, such as most rooms in more modern houses, will only need around 10 watts of heat per square foot.

In a room with many windows, such as a conservatory or a living room or dining room with large windows or sliding doors, you will need to increase your estimated wattage by around twenty five percent. If the room has a ceiling higher than eight feet you should also increase your calculated wattage by around twelve percent for each additional foot of wall height.

One tip to help your room to heat up better is if you find you will need a 2000 watt heater, or more, buy two heaters as opposed to one.  Setting two heaters at opposite ends of the room is more efficient than just having one larger heater at one end.  Finally, when in doubt as to exactly how big your heater should be, err on the side of getting a larger heater as opposed to a smaller one. That way you will be sure to stay warm.