26.08.2024
How does a combined how water tank for heat pumps work?
In recent years, air-to-water heat pumps have become one of the most popular types of heating in Europe and the Baltics, both as monoblocks and as split systems with split outdoor and indoor units. For both heat pump variants, there are several options for using the heat pump for hot water production in addition to heating, including indoor units with integrated hot water boilers or hot water boilers with an additional heat exchanger for connecting solar collectors or a high temperature heating system. In this article we will look at another type of tank for heat pumps - the combined hot water tank with two compartments.
This tank provides hot water in a similar way to a conventional boiler for heat pumps, by integrating a large area heat exchanger capable of heating the tank via a heat pump (or other low temperature heating source). In contrast, for combined heat pump boilers, a second, smaller tank, separated by a stratification plate, is located below this tank, which is used for the heating of the heating system circuits and acts as a storage tank. The stratification plate is necessary to minimise the heat exchange between them.
Due to its small volume, the integrated storage tank is only able to store heat for a short period of time, but for its main task of maintaining the temperature during the period when the hot water is being heated, its volume is more than sufficient. It should be remembered that an air-to-water heat pump with a separate hot water tank cannot heat the building and provide hot water at the same time, and during periods when hot water is being provided, the heating supply is switched off and the flow/return temperature of the liquid is reduced. The use of a storage tank in this case not only helps to maintain the heat during this short period, but also relieves the heat pump which would otherwise have to reheat the heating circuits - extending the working life of the heat pump.
When installing this type of tank, it is necessary to take into account their dimensions, which are larger than for conventional heat pump boilers. At the same time, they can be considered as a more compact solution than a hot water tank combined with a separate storage tank.
There are several models of combined hot water tanks available in our online shop, which can be found below:
- KOSPEL SWVPC hot water tank for heat pumps (250/60L);
- Dražice OKC/HR hot water tank for heat pumps (200/120L or 300/100L).