Heaters capacity and needs

The capacity of a heater is measured in BTU’s (furnaces, gas heaters, kerosene and propane heaters…) or in watts (electric heaters).

BTU and watts

A BTU is the acronym for British Thermal Unit. By definition a BTU is the amount of heat necessary to raise by 1ºF the temperature of 1lb of water.

To get – in BUT’s – the equivalent of the power of an electric heater, you have to multiply the number of watts by 3.41: a 1500 watts electric heater means a 5.115 BTU’s heater (1500 watts x 3.41).

Some references

Typical central furnaces can be rated 80,000 BTU’s. Many gas heaters have a rating around 39,000 BTU’s, while kerosene heaters power is often around 15,000 BTU’s.

Most electric space heaters have a much lower heat output than gas or kerosene heaters. Their capacity range is 1kW – 3kW (1,000 watts – 3,000 watts), that is, 3410 BTU – 10.230 BTU).

Many of the more potent electrical heaters have 1000 watts, 1,500 watts, 2,000 watts and 3,000 watts heat settings.

Your heating needs

Your heating needs and the size of your heaters depend largely on elements like your climate, the size of your rooms and home, your home’s insulation and air sealing, and… your goals.

For a small or medium sized room, a 3.000 watts heater is already a powerful unit… But not powerful enough if you have a large house, and intend to heat a large core of it.

Insulation and air sealing

A tightly insulated home, properly air sealed, will need smaller heaters: that’s why you should bet on insulation and air sealing, before compromising with heating systems…

The size of the rooms

A general rule, when selecting a space heater, is to have into account the size of the room. Do not bet on oversized heaters. Just take into account sizing tables. Most heaters come with them….

Goals

Anyway, size also depends on the type of heater and your goals.

If your goals are just heating a small room, for a short period of the year, then a small heater is a good solution. Pay attention, in this case, to the sizing tables.

If your goals is to get a good heat stream, directed to you, in colder days (without heating the whole room) then a small radiant heating is also enough.