the energy a heat pump uses is from the environment. However, the heat content of the air is around 3500 times less than that of the water. Also, a massive amount of heat is needed for heating when the air is particularly cold: in winter. This means that the heating output is also the lowest. Therefore, an air source heat pump makes the most sense in passive houses and other very well-insulated buildings that can be heated with a low flow temperature, says the building consultant.
There is another problem with air source heat pumps in winter: Temperatures around or below zero degrees, ice forms on the evaporator heat exchanger. This has to be removed regularly by supplying heat. A heating rod is integrated into the system for this. The consequence is higher electricity costs.
For example, alternatives are systems in the ground with geothermal probes that protrude up to 100 meters into the ground. Because at a depth of around 10 meters, the groundwater is about ten degrees warmer in every season. Or flat-plate collectors are laid in a serpentine shape and horizontally relatively close to the earth’s surface.
For the latter variant, a correspondingly large property is required. For the geothermal probes, the owner needs a permit for deep drilling and groundwater use. According to the expert, these are not simply granted at every location.
The geothermal systems work like refrigerators, but in the opposite direction: A cooling liquid is pumped through heat collectors or probes in the ground. It absorbs heat through the pipe walls and evaporates in the process. The gas is compressed and heated under high pressure by a heat pump. There is a transfer of heat in the heating system, and this occurs in the heat exchanger.