You may already know that heat pumps work by transferring rather than generating heat: they move heat outside in the summer and into your home during the cold season.
The second part may seem tricky. How do heat pumps work in winter? More specifically, how do they extract warmth from outdoor air when it’s significantly colder than indoors?
How Do Heat Pumps Work in Cold Weather?
Heat pumps are efficient reversible operation systems designed to keep your home comfortable in both hot and cold weather. Their setup allows heat extraction even when outdoor temperatures plummet.
How does that work? Thermal energy exists even in cold air. Heat pump refrigerants have extremely low boiling points (usually under -15 °F), so they can still absorb heat from frigid air. The refrigerant flows through the outdoor coil, pulls heat from the air, and turns into gas.
The heat pump’s compressor then compresses this gas, raising its temperature in the process. As the hot gas moves into the indoor coil, the heat exchanger extracts this heat and moves it into your home. The refrigerant turns liquid again, and the refrigeration cycle begins once more.
What If the Weather Gets Extremely Cold in Selma, TX?
Now you know the answer to “How do heat pumps work in winter?” However, you may still wonder, “Does it matter how cold it gets outside?”
Cold climate performance in heat pumps suffers when the temperatures drop below freezing. This happens for a few reasons. First, there’s less available thermal energy in extremely cold air, and the compressor and other heat pump components may struggle to transfer heat.
Moreover, when it freezes, frost and ice may settle on the outdoor coils, causing the heat pump to go into defrost mode and reducing its energy efficiency. Overall, standard heat pump models won’t work as efficiently when it’s below 25-30 degrees.
This is less of a problem in the San Antonio area, which rarely sees hard freezes. Nevertheless, you may need a backup heat source for the coldest winter days.
The Defrost Cycle
The defrost cycle is a critical part of “How do heat pumps work in winter?” When a layer of ice covers your heat pump during a freeze, the defrost cycle will start. This is a key function, since frost and ice won’t allow heat pumps to pull heat from the air as effectively.
During defrost, your heat pump will briefly switch from heating to cooling, reversing refrigerant flow. As the warm refrigerant flows through the outdoor coil, it melts the ice and restores heat pump efficiency. The entire process should take up to 15 minutes.
If your heat pump keeps going into defrost mode, or if it doesn’t activate defrost even when a lot of ice accumulates on the outdoor coil, call our heating repair services in Selma, TX.
Do You Need a Heat Pump Inspection Before Winter?
Although households in Selma, TX, enjoy mild winters, we still recommend scheduling a heat pump inspection before the cold season kicks in. A fall tune-up will address any wear and tear after a summer of hard use and uncover issues that could harm your heat pump’s winter performance.
The HVAC tech will replace the air filter, clean the coils, check the refrigerant levels, lubricate moving parts, and ensure that your system runs smoothly. If they discover any issue, you’ll have enough time to have it fixed while the weather is mild.
More Tips for Heat Pump Winter Use
Thankfully, heat pumps don’t need much maintenance beyond a biannual tune-up. Your unit should serve you well throughout the winter as long as you:
- Change the air filter according to the manufacturer’s instructions (usually every 1-3 months)
- Remove ice, grass, weeds, dry clippings, or any debris that might clog your outdoor unit
- Keep a two-feet radius around the heat pump’s outdoor unit clear from any vegetation
- Make sure your thermostat settings are correct and use a programmable or smart thermostat to save energy
- Pay attention to any performance issues like uneven heating or unusual noises
- Improve your home’s insulation, e.g., seal cracks around windows and doors, to prevent energy waste and excessive strain on the heat pump
Heat Pump Issues? Call Apollo Air Heating & Cooling, Your Trusted HVAC Service in Selma, TX
Whether you’re asking “How do heat pumps work in winter?” or need to fix a furnace with a cracked heat exchanger, we at Apollo Air Heating & Cooling are here to provide fast, efficient, and dependable HVAC services in Selma, TX. Text us or book a call online.