Buffertanks

A buffertank, also known as a thermal storage tank or hot water storage tank, is a type of insulated container used to store heated water. Its primary purpose is to decouple the heat source from the heat demand, allowing for more efficient operation of heating systems. Buffertanks are commonly found in hydronic heating systems, particularly those utilizing renewable energy sources like solar thermal collectors, heat pumps, or biomass boilers.

The core function of a buffertank is to absorb excess heat generated by the heat source when demand is low. This stored heat can then be released when needed, even if the heat source is temporarily inactive or producing less heat. This buffering effect helps to prevent short-cycling of the heating system, which can reduce efficiency and lifespan of components. For example, a solar thermal system might overheat the buffertank during peak sunlight hours, storing the energy for use during the evening or on cloudy days. Similarly, a biomass boiler can run at its most efficient rate, storing excess heat in the tank rather than shutting down prematurely.

Buffertanks are typically constructed from steel and are heavily insulated to minimize heat loss. They can vary in size depending on the heating system's capacity and the expected heat demand. In some applications, buffertanks may also incorporate internal heat exchangers, for instance, to transfer heat from a solar collector into the stored water. The controlled release of stored heat from the buffertank to the heating distribution system (e.g., radiators or underfloor heating) is managed by thermostats and control systems.