You can save a lot of money on heating in winter by using heat pumps in cold climates. Due to their efficiency and environmental friendliness, heat pumps have become a popular solution for heating homes. The units work on the principle of transferring heat from one environment to another. In winter, when the temperature outside drops, the question arises as to how these devices can provide enough heat for a comfortable stay. Their difference from other heating devices is their ability to use the energy of the environment to heat air and water.

The structure of a heat pump

Heat pumps use a refrigeration cycle to transfer heat from the environment to the interior of the house. In winter, they extract heat from the outside air masses, even at low temperatures, and transfer it to the indoor unit, which then distributes the heat throughout the room.

The heat pump consists of several components:

  • Compressor: It compresses the refrigerant, increasing its pressure and temperature.
  • Condenser: A heat exchanger where the hot refrigerant gives off heat and condenses, turning from a gaseous state to a liquid state.
  • Expansion valve: It reduces the refrigerant pressure and causes it to cool.
  • Evaporator: The liquid refrigerant absorbs heat from the environment and evaporates, turning back into a gas.

How heat pumps work in cold weather

The principle of operation of a heat pump in winter is based on a process known as the Carnot thermodynamic cycle. The compressor compresses the gaseous refrigerant, which leads to an increase in its temperature and pressure. The heated refrigerant passes through a condenser, where it releases heat to warm a room or heat water. It then condenses into a liquid state. This explains how heat pumps work in winter.

The liquid refrigerant passes through an expansion valve, where its pressure and temperature drop sharply. The cooled refrigerant liquid passes through the evaporator, where it absorbs heat from the environment (ground, air, or water) and evaporates, turning back into gas. This cycle is repeated constantly, pumping heat from one place to another.

Types of heat pumps

Heat pumps are classified based on their heat source:

  • Air-to-air: Heat is extracted from the outside air and transferred into the room.
  • Air-to-water: Heat is generated from the outside air and used to heat water, which is then circulated through the heating system.
  • Ground-to-water: Heat is harnessed from the ground, which requires drilling wells.
  • Water-to-water: Heat from water bodies (lakes, rivers, groundwater) is used to warm buildings.

Efficiency of heat pumps in winter

The efficiency of a heat pump is measured by its coefficient of performance (COP), which shows the ratio of heat energy received to electrical energy consumed. Under ideal conditions, it can reach a value of 3–5, meaning that for every kilowatt of electricity consumed, 3–5 kilowatts of heat are produced.

In winter, as outdoor temperatures drop and outdoor units accumulate snow, the COP also decreases. However, modern heat pumps can still operate efficiently in sub-freezing temperatures. For example, at −10°C, a heat pump can achieve a COP of about 2.5–3.0, meaning it produces 2.5–3.0 kW of heat for every kWh of electricity consumed. This demonstrates the equipment’s efficiency compared to traditional electric heaters, which typically have a COP close to one.

At what critically low temperatures can the pump operate?

Modern heat pumps designed for cold climates can operate efficiently at very low temperatures. They typically perform well at temperatures as low as −20°C, and some models can function effectively even at −25°C or lower. However, as temperatures drop further, their efficiency may decrease, necessitating additional measures to maintain sufficient heating.

Can heat pumps freeze in winter?

Outdoor units of heat pumps are susceptible to freezing in winter. One of the potential issues is the freezing of moisture condensed on the evaporator coil. This can occur even in moderate cold conditions. To address this concern, most modern heat pump models are equipped with an automatic defrosting system.

Self-defrosting function of heat pumps

To prevent the evaporator coil from freezing during extremely cold weather, heat pumps employ a defrost cycle. During this cycle, the heat pump temporarily reverses its operation, transferring heat from indoors to outdoors. This process helps melt any accumulated ice or snow on the evaporator coil. The defrost cycle typically lasts a few minutes and is activated automatically when the system detects ice buildup, ensuring continuous operation without user intervention.

How to improve heat pump efficiency in winter

The efficiency of a heat pump during operation largely depends on how well it is maintained and managed by its owners. There are several straightforward ways to enhance the efficiency of a heat pump in cold weather without requiring specialized skills:

  • Regular maintenance: Keeping the heat exchangers clean and in good condition increases efficiency.
  • Good insulation of the house: Ensuring proper thermal insulation of walls and roofs and sealing windows and doors minimize heat loss.
  • Use of a buffer tank: Using this helps save heat energy and ensures more stable system operation in very cold weather.
  • Optimization of settings: Setting the thermostat and pump to correct operating modes also increases efficiency.

Advantages of using a heat pump in winter

Energy-saving experts advocate for the use of heat pumps in cold climates due to their many benefits:

  • Environmentally friendly space heating technologies
  • Reduction of heating costs
  • Stable operation even in winter
  • Heating in winter and cooling in summer
  • Durability and stability due to the use of inverter motors
  • Heat is distributed evenly throughout the room

Features of heat pump installation

The installation of heat pumps requires careful planning and high-quality execution. It is necessary to choose the right place to install the outdoor and indoor units, connecting pipelines, circulators, and expansion tanks. After that, power should be provided to the equipment. The electrical connection must meet the requirements of the heat pump. Electrical work includes the installation of thermostats, temperature sensors, and control systems to optimize the pump’s performance.

The installation is completed by checking all connections, filling the system with coolant, removing air, and monitoring the pump. Without experience, it is difficult to perform all these works under local building codes and safety standards. That is why specialists are invited to install, repair, and maintain heat pumps.

Rocky Mountain is your close, reliable partner

Our experts will take care of your comfort. We have a team of certified specialists and licensed equipment for climate technology. We provide installation, repair, and maintenance services for heat pumps. We will make the first launch and guarantee the stable operation of the equipment. If necessary, we will calibrate the system to achieve optimal efficiency.

Contact us now!