Unlike a furnace, a heat pump doesn’t burn fuel to make heat, as it’s powered by electricity. During the summer it acts like an air conditioner and works by moving heat from the inside your home to the outside. In winter, the heat pump reverses this by bringing in heat from the cold outdoors with the help of an electrical system, and discharging that heat inside the house. Almost all heat pumps use forced warm-air delivery systems to move heated air throughout the house. A heat pump is an energy efficient way to cool your home in the summer and heat it in the winter.
There are two relatively common types of heat pumps.
Air Source Heat Pumps, also called reverse-cycle air conditioners, air source heat pumps transfer heat from outside a building to inside during colder months, and even from inside to outside during warmer months. They extract energy from the air (even at freezing temperatures) and transform it by a method called vapor compression refrigeration to heat, providing temperatures of up to sixty degrees Celsius to heat water, floors and radiators. They’re emission-free (so long as they don’t leak the refrigerant cooler) and thus eco-friendly. They’re also low maintenance, relatively quiet and cost effective, no matter what brand you buy.
Ground-source heat pumps, also called geothermal, GeoExchange, or GX, get their heat from underground, where temperatures are more constant year-round.
A ground source heat pump (GSHP) is a central heating and/or cooling system that transfers heat to or from the ground. It uses the earth as a heat source (in the winter) or a heat sink (in the summer). During the summer, geothermal heating and cooling systems absorb heat from your home and transfers it to the underground loop where it is then absorbed by the cooler earth. The geothermal heat pump uses the cool water returning from the ground to create cool, dehumidified air conditioning for your home.
When you need cooling the most, the outside air is hottest. A traditional air source heat pump must work hard to force the heat from your home into the already heat saturated air. In contrast, a geothermal heat pump consumes less energy as it easily rejects heat into the cool earth, making geothermal cooling significantly more energy efficient.
Air-source heat pumps are far more common than ground-source heat pumps because they are cheaper and easier to install. However, Ground-source heat pumps, are much more efficient, and are frequently chosen by consumers who plan to remain in the same house for a long time, or have a strong desire to live more sustainably.
Heat Pump Efficiency:
The Seasonal Energy Efficiency Ratio (SEER) is the measure of efficiency by which the cooling process of air conditioner and heat pump systems is rated. The higher the SEER number, the greater the efficiency, and therefore the greater the energy savings. Today, U.S. regulatory agencies require all new products to have a 13.0 SEER rating or better. The highest SEER rating for heat pumps is 20.0.