An electric heat strip is a heating device that is often used to supplement a heat pump, providing additional heat when external temperatures decrease enough to prevent the furnace from maintaining the desired temperature. Electric heat strips are also referred to as electric resistance heat, auxiliary heat and emergency heat.
Electric heat strips resemble the coils in toasters and are housed inside air handlers of HVAC systems. Although electric heat strips are generally utilized as a supplementary source of heat, some homes use this heating mechanism as a primary heat source. Supplementary electric heat strips usually turn on when a building's inner temperature drops at least two degrees below the temperature that is set on the thermostat. These heat strips are also triggered on if a thermostat's setting is raised too quickly.
Energy experts advise against the use of electric heat strips as they can greatly increase heating costs. Electric heat strips require high amounts of electricity and are much less efficient than traditional heat furnaces. They work at 100 percent efficiency, while heat pumps work at 200-300 percent efficiency. Suggestions to avoid using heat strips include raising the thermostat temperature by only two degrees at a time and using a programmable thermostat, which changes the temperature based on user-specified settings.