Indirect heat interface unit
Heat Interface Units (BG 62/2015) was written by Reginald Brown and published by BSRIA in December 2015. It states: ‘An indirect HIU (heat interface unit) in this guide refers to an HIU where there is hydraulic separation between the heat network and the secondary space heating circuits. The secondary heat distribution system must therefore include independent provisions for filling, pressurisation, circulation and water treatment. An indirect HIU for residential consumers may include separate plate heat exchangers for heating and domestic hot water. These heat exchangers are sometimes referred to as the “heating plate” and the “hot water plate” respectively.'
More details of the key features and construction of direct and indirect HIUs, including variations associated with domestic hot water production and storage, are given in Sections 7 and 8 of the guide.
--BSRIA
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