What is a heat pump, how does it function and what are its advantages?
Heat pumps for the heating of premises are universal high-tech climate devices that combine several types of equipment: hot water heating for the house, a source of hot drinking water and air conditioning.
The main task of any heat pump is to select the heat of a renewable energy source (air, water, soil, sun) and redirect it to the heating system of your premises. The advantage of this principle of heating in comparison with traditional sources of heat or cold is the ability to convert the renewable low-temperature energy of the environment.
The principle of the heat pump is as follows: with the help of the compressor, the scattered low-potential thermal energy is compressed. In a compressed state, the thermal energy of low-temperature air or water has a higher concentration and, consequently, a higher temperature. Thus, up to 75% of the energy needed to heat or cool the home, office, residential and industrial premises with the help of a heat pump is drawn from the environment. In turn, the energy costs for the operation of the circulation pumps and the heat pump compressor are the remaining 25%. The heat pump system has no limitations and is capable of producing heat using all existing energy sources irrespective of temperature. The carrier of thermal energy is any substance with a temperature above absolute zero.Compression and conversion of thermal energy with the help of a compressor makes it possible to obtain a high temperature. The main indicator of the efficiency of the heat pump is a high coefficient of heat conversion. The heat pump will utilise electricity exclusively on compression and transfer of natural heat, which is itself free of charge.Thus, heat pumps produce 10 kW of thermal energy, consuming on average only 1.5-2.5 kW / h of electrical energy.
Heat pump operation
The principal of how a heat pump functions
The propylene-glycol solution circulates in the external collector, absorbing the thermal energy of the soil, air, water or sun. The circulation pump ensures the propylene-glycol solution flows through the pipes of the external circuit through to the evaporator (heat pump heat exchanger). In the evaporator, the refrigerant boils, so that heat is removed from the solution. The refrigerant vapor from the evaporator enters the compressor and is pumped into the condenser. In the condenser a process occurs that is inverse to the evaporation. Under the influence of high pressure, the coolant passes from the gaseous state to the liquid state. This generates a lot of heat. Passing through the expansion valve, the refrigerant enters the low-pressure zone of the evaporator, effervesces and the cycle repeats.
Classification and types of heat pump circuits
The most common Geothermal sources for heat pumps.
Horizontal Circuit or Looped Circuit
The application of this type of external circuit assumes the presence of an appropriate adjoining territory, where drilling operations are impractical. It should also be taken into account that in the future, construction of structures and planting of trees is impossible on this site. A heat pump based on a horizontal circuit is a versatile device for generating both heat energy and cold. The air-conditioning system (fan coils, cold walls etc.) based on the heat pump provides an environmentally friendly and comfortable cooling of your home. At the same time, the preparation of hot water is completely free. Installation of a horizontal circuit involves laying a pipeline into the soil to a depth of 1.2 - 2.5 m, in which a non-poisonous liquid circulates. The minimum distance between adjacent pipelines is 1 m. In this situation, the length of the pipeline directly depends on the power of the heat pump. Approximately, 20 W of thermal power corresponds to 1 m of the pipe. Thus, to install a heat pump with a capacity of 10 kW, an earth circuit with a length of 500 m is required.
Vertical Circuit
The vertical power take-off loop is the optimal solution for areas with a small adjacent territory or landscaped areas where the integrity of the territory can not be violated. To install a vertical circuit you need a very small piece of land, but you need to drill. Regardless of external weather conditions, the soil temperature at a depth of 50-100 m is from +6 to +10 ° C. During the summer period, the use of heat energy is directed to ensure the operation of the air conditioning system. The installation of a vertical circuit involves drilling a series of holes in the ground up to 100 m deep. Probes - polyethylene pipes 40 mm in diameter, welded together by a U-shaped joint and filled with non-freezing, non-polluting liquid, are dropped into the holes. The depth and number of drilled holes depend on the power of the heat pump. So, for a heat pump with a capacity of 10 kW, 4 holes with a depth of 50 m each are necessary.The distance between the holes should be at least 6 m.
Water (Pond) Circuit
The presence of a reservoir provides the possibility of selecting low-potential energy of water. Advantage of this method: does not require significant investment (no drilling or excavation). In hot summer days, the issue of cooling rooms becomes particularly topical. With the optional equipment, the heat pump can operate in the conditioning mode. In this case, the cold is applied to the air conditioning devices (fan coils, cold walls, etc.). The heat generated during this process is sent to the preparation of hot water, heating the pool, etc. When installing the water circuit, polyethylene pipes filled with non-freezing liquid are laid on the bottom of the pond. In order that the pipeline does not float to the surface, the weighting agent is fixed at the rate of 5 kg per one meter of the pipe.
Groundwater Circuit
Groundwater collectors
Groundwater is the most efficient source of energy extraction due to a fairly high (+8 to +10 ° C) and stable temperature throughout the year. This type of circuit allows the operation of a heat pump with a very high coefficient of productivity (COP). In a warm period of time, groundwater is a source of energy for obtaining cold. In this case, the operation of the heat pump in the conditioning mode can be of two types: active conditioning and passive conditioning. When installing a heat pump circuit on groundwater, two shallow (up to 30 m) wells are drilled at a distance of 25-30 m from each other - the supply and the receiving one. With the help of a deep pump, water from the supply well is fed to the heat pump heat-exchanger, and after the heat is released, it is discharged into the receiving well.
Economical and highly efficient
The heat pump can reduce the heating bills due to the efficient use of energy (from 1 kW of electricity, the heat pump generates 3-5 kW of heat).
3 in 1 system
The heat pump is the only device that you need to install to provide the premises with heat in the cold periods, cooling in the hot season and uninterrupted hot water.
The main advantages of geothermal heat pumps:
- stable characteristics that do not depend on the weather or season, since the temperature of the soil or the well is constant;
- high efficiency, thanks to a high level of COP (up to 5);
- The well or bore hole occupies a minimum of the site;
- long service life;
- ecological method of heating and air conditioning;
- security;
- simplicity and convenience in management;
- possibility of setting modes, which saves energy;
- autonomy from any type of fuel, such as gas, oil or other.
Through the specialist installation partners of KETE-RVS you can choose and buy a geothermal heat pump for heating your premises at favorable prices. Our specialist installation partners will perform the sizing, specification, installation and configuration of a heating system to a high-quality and in a prompt manner.
