What Is a Heat Pump and How Does a Heat Pump Work?
Considering investing in a heat pump? Understanding what a heat pump is and how it works can help determine whether this HVAC system is suitable for your home.
Q: We’re looking to replace our HVAC system and saw an option to purchase a heat pump instead of an air conditioner and a furnace. What is a heat pump, and how will it work in our home?
A: Simply put, a heat pump moves heat from one place to another. It differs from other HVAC systems because it uses energy to pull heat from the outside and transfers it to the inside. It goes through a process of compression and exchange to increase the air’s temperature and reverses the process to decrease the air’s temperature.
This is what makes the heat pump notable: its ability to cool a house during hotter weather and heat it during the cold. This dual-purpose and energy-efficient system can save a lot of money in the long run instead of investing in separate heating and cooling systems.
A heat pump is a part of a heating and cooling system and is installed outside the home.
Air conditioners, furnaces, and heat pumps are all HVAC systems. The heat pump, however, can act alone and perform both heating and cooling. In certain situations, it may be ideal for pairing it with a backup system like a furnace, but it does have enough electrical power to transfer heat and cool air into a home.
There are a few types of heat pumps on the market, but most models have a larger unit installed outside the home and a smaller, more compact or wall-mounted unit inside. These types of heat pumps are called split-ductless. Other pumps have only one outside unit or have looped pipes beneath the ground.
A heat pump is capable of using air to cool or heat your home by redistributing heat.
No matter what the temperature is outside, a heat pump can gather heat located in the ground or air outside the home. The pump takes the heat into the system, compresses it to increase the temperature of a refrigerant, then pushes the hot air into the home. When the weather gets hotter, the system reverses and acts like an air conditioner; it moves heat from inside the home and transfers it outside.
Heat pumps use a variety of parts to run. There are two types of compressors: two-speed and scroll. The two-speed compressors help the pump reach an ideal temperature, and the scroll compressors work to compress the refrigerant to warm up the air. In addition, variable-speed motors are located on the system’s fans, either inside or outside, and they help maintain a steady flow of air from the unit to the home.
The two most common types of heat pumps are air-source pumps and ground-source pumps.
The main difference between an air-source pump and a ground-source (or geothermal) pump is the heat source. Air-source pumps have a unit outside the home and an internal piping system that extracts heat from the outside air and moves it indoors. This type of heat pump can also be paired with an air-source hot water heat pump to provide homeowners with hot water.
Ground-source heat pumps utilize a buried looped pipe system to gather and transfer heat from the ground. These types of pumps are better suited for larger properties where there is enough space to install the pipes into the ground. Ground-source pumps are also more effective in the winter because they draw from consistent thermal energy underneath the ground.
The most effective heat pump for someone’s home is determined by the specific purpose of the pump, the energy consumption rate, noise level, installation and maintenance costs, and the amount of space on the property.
Heat pumps are most common in milder climates where temperatures rarely drop below freezing.
While heat pumps can certainly keep your house warm during the winter, they may take longer in areas where the climate is colder and can drop below freezing. When a heat pump collects heat from outside, it becomes difficult once the air drops to a low enough temperature. The ground-source heat pumps will be more efficient during winters than the air-source pumps, but homeowners may want to consider a supplement to the heat pump if living in colder climates.
For those areas, the heat pump should be paired with a furnace. On the days when the temperature drops too low for the heat pump, the furnace will be used to heat the home. This can save money during the winter if gas prices are lower than running electricity.
Like with any part of a heating and cooling system, heat pumps need regular maintenance.
Dirty heat pump components, like coils, filters, and fans, can alter the air quality inside the home. It’s crucial to maintain a clean heat pump and ensure all parts are running correctly. If the pump does not get regular maintenance, the system can become damaged and eventually stop working properly, resulting in homeowners replacing it.
The heat pump filters need to be changed about every month, or more often if necessary, so the air coming through is clean and steady. Additionally, the fans may need to be dusted and cleaned, both inside and outside, as well as the coils.
Be careful when cleaning out the pump to ensure nothing is damaged or replaced improperly. If any issues arise, consult the manufacturer’s guide or consult a professional. Homeowners may have professionals come out to check for any leaks, damaged parts, temperatures or pressures of refrigerant, and airflow.
Always call a professional if you are experiencing issues with your heat pump.
Sometimes an issue may arise inside piping, under the ground, or inside a unit that a homeowner may not be able to see or diagnose. It’s essential to contact a professional who knows the inside and out of the system to help find the issue. Once found, they will be able to provide a solution and may also have advice for preventing it from happening again in the future.
If the air isn’t flowing steadily, the temperature isn’t rising, cool air is releasing instead of heat, or the system isn’t working correctly, it’s time to call a professional. Be sure to ask questions and seek help when needed.