Although at first glance seems impossible, this system uses well-known principle of latent heat.
At the conference Energy efficiency in buildings organized by AHK, Bojan Grujički from Viessmann presented, among other things, and an innovative heating system using ice. This concept is based on the exploitation of solar and geothermal energy through the buried ice tank filled with water in which the temperature drops until the crystallization and the use of energy in the tank does not create ice.
Ice tank is buried in the ground at a depth of about half a meter where there is a constant temperature. The secret of the whole system is just in the way of exploiting the ice reservoir since it draws heat from not only when the water is totally cool, but until it reaches its freezing, or crystallization, which maximizes the energy stored in it. Namely, the reverse process of melting of the ice requires the same amount of energy as the lifting of its temperature in the range from 0 to 80 degrees Celsius.
A reservoir of ice, pulls the heat that is used for the heat pump and provides heat for heating the hot water tank that can be used for domestic hot water and for heating the house. For a typical family home is sufficient system with icy reservoir of 12 cubic meters combined with a heat pump and solar collector systems with a total output of 7.5 kW, covering the needs of heating and domestic hot water.