Heat Pumps: How Energy Efficient Are They?
As compared to air conditioners and furnaces, heat pumps are more energy-efficient. Heat pumps transfer heat instead of producing it from fossil fuels. Used in heating and cooling your home.
What is a Heat Pump
A heat pump is a two-component, stand-alone appliance that provides heating and cooling for households, businesses, and other applications using refrigeration technology and electricity. A heat pump is made up of two parts: a condenser unit that usually sits outside of a house and creates heating and cooling, and an interior unit that normally sits on a wall and passes hot or cold air into the home.
Heat pumps are often referred to as “mini-splits” because the condenser and air handler are separated by a refrigerant line, like what a mini-split air conditioner has. Heat pumps have very high-efficiency ratings. They have the ability to provide heating and cooling without the use of ductwork in homes, that’s why they are referred to as “ductless” because they don’t need ductwork.
Understanding Efficiency
You can determine the efficiency of heat pumps by how effective they keep your home cold or warm.
The amount of energy a system provides to your home versus the amount of energy it absorbs is referred to as efficiency. The most efficient devices produce several times more energy than they absorb.
Energy is produced by burning fossil fuels in furnaces and boilers. The efficiency of these systems ranges from 78 to 98 percent. Instead of using fossil fuels, a heat pump uses electricity. And so, it is more energy efficient than most heating and cooling systems
Toasters and electric heaters are both 100% efficient. This suggests that they provide as much heat as they absorb in terms of energy. A heat pump, on the other hand, will provide up to 300 percent of the energy that it consumes. Ground-source heat pumps, which depend on the steady temperature under the earth’s surface, may achieve higher efficiencies.
What Makes Heat Pumps So Efficient?
Heat pumps collect heat from the air outside or underground and send it to the house instead of producing it. Heat pumps also absorb excess heat from their own fans and return it to your house.
A heat pump’s efficiency is determined by the cost of fossil fuels versus electricity. For example, most Americans favor an electric heat pump over a boiler that runs on oil or propane. In the United States, the cost of these fossil fuels is very high. Since natural gas is less expensive than electricity, some still prefer a natural gas furnace over an electric heat pump.
If you are living in an area where electricity is affordable, it is best to choose a heat pump. Solar-powered & Geothermal heat pumps are even more efficient at transferring energy from the outside to the inside of the home.
Grading A Heat Pump’s Efficiency
Heat pumps have two efficiency ratings since they both heat & cool your homes. Residential heat pumps are rated using various metrics by manufacturers.
The efficiency of a heat pump in cooling mode is measured by the SEER (Seasonal Energy Efficiency Rating). A device with a higher SEER rating is more effective. The SEER ranking is calculated by dividing the amount of heat removed from your home by the time the machine was operational during the cooling season. The method takes into account temperature variations during the cooling cycle to ensure accurate ratings.
14 SEER is the average SEER level for heat pumps, according to the Department of Energy.
High efficiency heat pumps have a SEER of 18 or higher, they may even have a Energy Star rating of up to 27.5 SEER.
The Heating Seasonal Performance Factor, or HSPF, is a measurement of how much heat a pump transfers to your home and how much electricity it absorbs. A high HSPF indicates greater efficiency.
Manufacturers should consider the changes in outside temperature when calculating HSPF. The least efficient rating for a heat pump is 8.2 HSPF. The HSPF rating of most Energy Star-rated heat pumps is between 10 and 13, according to the Department of Energy.
Geothermal Heat Pump Efficiency
Geothermal heat pumps rely on the heat on the temperature underground, instead of relying on the air outside. They are more efficient compared to air-source heat pumps. The efficiency ratings of these heat pumps vary from those of traditional heat source pumps.
The efficiency of geothermal heat pumps during the cooling season is measured by the EER (Energy Efficiency Ratio). It’s similar to the SEER Rating for air source heat pumps, except it’s focused on a particular temperature instead of varying temperatures.
The efficiency of geothermal heat pumps during the heating season is measured in COP (Coefficient of Performance). It’s similar to HSPF, but it’s calculated at a specific temperature. The COP ranking is based on a set temperature. Since the temperature of the ground or water does not change, COP is a more precise measure of the system’s efficiency.
The minimum cooling efficiency for geothermal heat pumps is 16.1 EER, according to the Department of Energy. Some systems have an EER of 30 or higher, indicating that they are extremely effective. The Department of Energy suggests a COP ranking of 3.1. The COP in certain systems is 4.5 or higher.
Factors Affecting the Efficiency of Heat Pumps
Heat pumps, according to the Department of Energy, will cut home electricity use by more than half. Heat pumps get their energy from a variety of sources, each with its own set of benefits.
During the heating system, air source heat pumps convert heat from outside your house. Electricity is used to fuel them. Split-system heat pumps have outdoor & indoor units. This is an ideal option if you are looking for a low cost heat pump, but is less efficient compared to geothermal heat pumps.
Electricity is used to fuel mini-split ductless heat pumps. These devices also absorb heat from the outside air and pass it to your house. They’re most efficient when you just need to heat one room.
Geothermal heat pumps are the most efficient as they draw heat either from the ground or from water. These heat sources are fairly constant. Geothermal ground-source heat pumps transfer heat to or from the ground and to or from your house, depending on the season. Although these systems have high efficiency, they are relatively expensive to install.