Home heating with heat pumps

Heat pumps can heat your home during the cold season, cool it during the summer, and provide hot water throughout the year. They run on energy from various renewable sources, converting it into thermal energy using refrigerants.

The design of heat pumps provides for the presence of 2 parts: one is outside and absorbs the thermal energy of a renewable source, and the other — internal — transfers the received heat to the heating or air conditioning system.

Modern models of heat pumps allow you to save about ¾ of the money on heating or cooling a house that would be spent on the same purposes in the absence of a heat pump. Such high energy efficiency is possible due to the fact that the heat pump system performs cooling or heating using free sources — the heat of the soil, groundwater, exhaust air leaving the premises.

There are several cycles in the operation of a heat pump:

1) Evaporation. A closed complex of pipes located in the ground (outer part) absorbs the thermal energy of the soil, as a result of which the refrigerant in the pipes becomes gaseous. The refrigerant vapor is then sent to the compressor. It is important to remember that the pump pipes must be located below the freezing point.

2) Compression. The compressor strongly compresses the gaseous refrigerant, which causes its temperature to rise rapidly.

3) Condensation. Heated steam under high pressure is in the interior of the heat pump. It is used to heat water or rooms, while giving them their heat, the refrigerant returns to a liquid state.

4) Extension. In the expansion valve, the pressure of the resulting liquid is reduced. After that, all stages of the cycle are repeated.

The energy efficiency of heat pumps is higher than that of other heating devices, and is 300%. This means that the pump produces 4 kW of useful thermal energy, consuming 1 kW of electricity. However, energy efficiency figures may vary, for example, depending on the soil in which the external part of the earth pump is located. Sandy soil will reduce its energy efficiency by almost 2 times. Also, energy efficiency decreases at low air temperatures.

During the summer months, the heat pump can be used to cool and air-condition your home. The principle of operation of a heat pump in cooling mode is similar to that of a heating system, with the difference that the heat pump does not use radiators, but fan coil units. In the passive cooling mode, the compressor is not involved — the refrigerant simply moves between the well and the fan coils, i.e. cold comes from the well into the house. If it is not enough, then the compressor starts up and makes the temperature of the refrigerant even lower.

There are 3 types of heat pumps for domestic purposes:

• «Earth» or «ground-water», «ground-air». They are the most popular. The efficiency of these heat pumps, as well as the price, is higher than that of other types. Depending on the location of underground pipes, earth heat pumps are divided into vertical and horizontal. Vertical ones require the creation of a deep well for laying pipes — from 50 to 200 m. You can make several shallower wells at a distance of more than 10 m from each other, but even in this case their depth should not be less than 50 m. The required depth is determined depending on heat pump power: for example, with a power of 10 kW, a total well depth of at least 170 m is required.
• When installing a horizontal heat pump, deep immersion of pipes is not required — 1 m is enough. But you will need a fairly large area of ​​u200bu200bthe site — about 400 m2. The exact depth of laying the outer part of the horizontal heat pump is determined by the terrain. Pipes should be located at a distance of at least one and a half meters from each other. With a power of 10 kW, the total length of the pipelines should be about 350 — 450 m. «Earth» heat pumps are optimal for regions with a temperate climate.
• «Water» or «water-water», «water-air».
• «Air» or «air-to-water», «air-to-air». Suitable for areas with a mild climate, where the temperature range is small.
• It is worth remembering that water and air heat pumps are more prone to energy efficiency losses than earth heat pumps.

According to the power source, electric heat pumps and gas heat pumps are distinguished. Models of the first type are more widespread.

Combining different types of heat pumps will help achieve greater energy efficiency in adverse climatic conditions.

Heat pumps, like any other technique, have their pros and cons. Among the indisputable advantages are economy, safety, noiselessness and ease of use — in the presence of heating radiators and fan coil units, you can switch the pump from heating mode to cooling mode, and vice versa.

The disadvantage of heat pumps is the rather high installation costs. In addition, until recently, the coolant could only heat up to 60 degrees. In modern models, this problem has been eliminated, however, such heat pumps are more expensive.