Electric building heating methods

Electric building (space) heating converts electrical energy into heat to keep rooms at a comfortable temperature. It is clean, needs no fuel storage or chimney, is easy to control with thermostats, and has nearly 100 % conversion efficiency at the point of use (heat pumps give even more heat than the electricity used). The main methods are:

1. Direct resistance heaters

Current through a resistance element produces heat (I²R).

• Convection heaters (convectors): an element at the bottom heats air, which rises and circulates through the room by natural convection. Oil-filled radiators work the same way using oil as a heat store.
• Fan heaters / forced-air heaters: a fan blows air over the hot element; heats a room quickly.
• Radiant heaters: a red-hot element with a reflector (bar heater, quartz/infrared lamp) radiates heat directly onto people and objects; good for large halls and outdoor areas.

2. Embedded (panel) heating

Heating cables or panels are buried in the floor, ceiling or walls. The large warm surface heats the room by low-temperature radiation and convection. Underfloor heating gives uniform, comfortable heat and no visible equipment.

3. Storage heating

Heaters with a block of high-heat-capacity material (bricks, ceramic) are charged at night with cheap off-peak electricity and release heat during the day, controlled by dampers. Flattens the utility load curve.

4. Central electric heating

An electric boiler (resistance or electrode type) heats water or air, which is circulated through radiators or ducts to all rooms. Suits large buildings.

5. Heat pump heating

A vapour-compression heat pump (reverse-cycle air conditioner) extracts heat from outside air or ground and delivers it indoors. It gives about 3 units of heat per unit of electricity (COP ≈ 3), so it is the most energy-efficient electric method, and the same unit cools in summer.

6. Infrared heating

Infrared lamps or panels heat people and surfaces directly, not the air; used in factory work bays, warehouses with high ceilings and loading docks.

Control: thermostats, timers and zoning switch the heaters on only where and when needed, which saves energy.