How Heat Pump Hot Water Heater Cold Climate Work in Winter?

The heat pump water heater can efficiently provide hot water to the home. What about in the cold winter? Can heat pump hot water heater cold climate work well? Yes, it can.

Cold air has heat

The heat pump hot water heater cold climate is specifically designed to work at temperatures as low as -25C (-15F) below the freezing point. Few people realize that the air below the freezing point has almost the same relative energy as the air above the freezing point. By understanding the concept that air contains energy, we can begin to understand the working principle of cold climate heat pumps. Only in a space with a temperature of -273 C (absolutely zero), there is no energy in the air.

Warm always turns to cold

This is the next principle used in cold climate heat pumps. Compared with cold air, warm air has more energy and more molecular collisions, and will naturally migrate into cold air until equilibrium is established. Therefore, using a colder liquid, such as freon, which will not freeze before -50, we can make the warm -25 C air transfer its energy to the colder freon in the heat pump.

Pressure determines boiling point

Different substances have different boiling points, which can be changed by increasing or removing pressure. The water boils at 100 C and 14.69 Psi (sea level). However, when we lower the pressure, it will boil faster. On Mount Everest, where the pressure is only 4.89 psi, the boiling temperature of water is about 71 degrees Celsius. This is because the pressure is less. The refrigeration cycle uses Freon, which changes from liquid to gas at a lower (cooler) temperature than water. By adjusting the pressure of Freon, we can control when this phase change occurs. Our heat pump uses a refrigerant called R410a, which is more suitable for storing energy in colder conditions. By reducing the pressure in the heat pump, the temperature of this refrigerant can reach -50°C.

The cold -50 Freon passes through the heat exchanger, and the warm energy of the outside air (-25 degrees Celsius) is naturally transferred to the colder Freon through the heat exchanger. This causes Freon to absorb energy. When it heats up, Freon begins to evaporate (boils) and becomes a gas, and then the Freon gas is brought to the compressor for compression, so that its temperature increases greatly as the volume decreases. This hot gas is then transferred through another heat exchanger, where the colder water/glycol is on the other side, and the energy is again transformed from hot to cold, and heats the water/glycol circuit in the home. The refrigerant loses heat, cools it back to liquid, and starts the cycle again.

This is the basis of the refrigeration cycle. If you understand these basic principles, you can master the working principle of the heat pump even at -25 C (-15 F). A heat pump is just a means of transferring energy from one source to another. This is the same principle used in geothermal, which extracts warm energy from the ground and transports it to the house through a series of heat exchange processes.