Direct heat interface unit
Heat Interface Units (BG 62/2015) was written by Reginald Brown and published by BSRIA in December 2015. It states: ‘A direct HIU (heat interface unit) in this guide refers to an HIU where water from the heat network is circulated through the secondary space heating circuits. There is no hydraulic separation between the heat network and secondary space heating circuits. A direct HIU for residential consumers may include a plate heat exchanger for domestic hot water. This is sometimes referred to as a “hot water plate”. Alternatively, hot water may be provided from an indirect domestic hot water cylinder.’
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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