Unlike conventional electric furnaces, which burn fossil fuels to produce heat, heat pumps simply move energy from the air, water or ground into your home. They’re one of the fastest-growing appliances in the world and are gaining popularity in an increasingly eco-conscious climate. And they’re much cheaper to run than conventional gas furnaces. But the technology requires a different sales pitch than solar panels and electric vehicles, and many HVAC contractors have pooh-poohed them in favor of fossil-fuel-burning furnaces. Canary Media has tracked the evolution of this efficient, cost-effective heating option and brings you this user’s guide to making the switch to heat pumps.
A heat pump extracts energy from the air, geothermal power stored in the ground or waste heat from a factory. It amplifies that energy to heat your home in winter and cool it in summer. The system’s efficiency is often four times higher than traditional furnaces or boilers, with the electrical energy consumed to operate it normally being several times less than that used by other heating technologies.
Heat pumps are based on the same refrigeration cycles as a refrigerator or air conditioner, but the process can be reversed to either heat or cool a space. The basic premise is that the temperature of the surrounding air or ground is almost always warmer than that of the refrigerant, which moves between two coils to extract and deliver energy.
The system is powered by an electric motor that drives a compressor to pressurize the refrigerant, turning it into a hot liquid. Then the liquid is drawn into an evaporator coil, where it evaporates at the sudden drop in pressure, releasing thermal energy to warm your home. The refrigerant is then returned to the condenser coil, where it reverts back to a hot liquid and the cycle starts again.
As this process goes on, the amount of electricity consumed is directly proportional to the amount of energy produced. This is why heat pumps are rated by their Seasonal Energy Efficiency Ratio (SEER) or Heating Seasonal Performance Factor (HSPF).
One of the best things about heat pumps, in addition to their efficiencies, is that they require no fuel to generate their energy. That means they have the smallest carbon footprint of any heating system, even when compared to oil- and natural gas-fired furnaces. And as the percentage of renewable and low-carbon sources in the power mix increases, that footprint will shrink even more.
There are several types of heat pumps on the market, including ductless mini-splits. These are perfect for homes that don’t have ducts, and can be an effective replacement for air conditioning systems in those spaces. The most common type of Heat Pump is a split-system that has an outdoor unit that looks like a regular air conditioner’s outdoor unit, and an indoor air handler. There’s also a newer version of the heat pump called a hybrid that uses an electric motor to drive a small steam turbine to create supplemental energy.