Domestic hot water consumption in educational premises, apartment and office buildings

摘要

Investigations of domestic hot water (DHW) consumption and the consumption profiles have been carried out in many countries. Over-dimensioning of systems and equipment has been observed in the US. The last 15-20 years have seen drastic changes in people's DHW consumption in Estonia. Great changes have also taken place in top consumption. In Estonia it is customary to determine DHW design flow rates for schools and children's institutions, residential and office buildings proceeding from the sum of the standard flow rates. The design flow rate calculated by standard EVS 835:2003 for residential and office buildings, ordinary schools and children's institutions are considerably bigger than the actually measured ones. For determining the design flow rates for the determination of the water heating devices for schools, children's institutions, office and residential buildings calculation formulas are recommended. By the recommended formulas the design flow rates for ordinary schools are approximately 1 ... 1.2 times smaller than those calculated by the EVS standard, 1.1 ... 2.1 times smaller for children's institutions and 2 times smaller for office and residential buildings. Recommended calculation formulas reduce over-dimensioning both the DHW instantaneous heat exchangers and the flow rates of the district heating network.