Thermal energy storage in buildings makes district heating more climate friendly
Phys.org, May 5, 2015. Image credit: PublicDomainPictures
District heating is a common for heating buildings and hot water in many Swedish cities. The heat is largely produced from residual products from forestry, household waste, or waste heat from industries.
But now John Kensby, a PhD student in building services engineering, has shown how it can be avoided in a cheap way: simply by storing heat in the buildings that are already connected to the district heating network.
In a pilot study, he investigated how the indoor climate is affected if the district heating system is allowed to provide the buildings a little more heat in the radiators at times and a little less at other times. It turned out that it is possible to store as much as 0.1 kilowatt hours of heat per square meter of a building without the indoor temperature varying by more than 0.5 degrees Celcius.
Thus it is possible to even out the load on the heating system. Faced with an expected peak, such as morning rush to the shower, the system can prepare by heating the radiators in the buildings a little extra for a few hours in advance. A five-minute shower “costs” about 2 kilowatt hours, which means that an apartment of 80 square meters can store heat energy equivalent of four showers.