What Are Heat Interface Units?

Courtesy of CIBSE

Heat Interface Units (or HIUs) are not new to the heating industry, however they are now becoming a lot more popular, especially in shared and district schemes. They are often installed in large complexes that have multiple dwellings where, instead of fitting each dwelling with its own boiler, one central boiler supplies all of the domestic hot water and heating energy to the whole complex. HIUs perform the role of a bridge between the hot water and heating systems of the individual flats and the central boiler itself.

Why Are Heat Interface Units Becoming More Popular?

One of the main attractions of HIUs today is the opportunity for renewable energy that they provide. With energy efficiency being more important than ever, HIUs allow energy conservation through the usage of energy efficient plants, with hot water being produced by a district heating plant and being transferred through heat exchangers to supply on demand hot water and heating. HIUs can be powered by sources of renewable energy and can deliver eco-friendly temperature controls to the occupants of the building. The district heating systems for modern multi-dwelling compexes can use sources such as heat pumps, CHP or solar heat which is more convenient than equipping individual dwellings with their own source of renewable energy. As hot water is supplied rapidly through a plate heat exchanger, the occupants of the building also enjoy higher comfort levels.

multi-unit district hot water and heating

Courtesy of Duty Point

Heat Interface Units supply domestic hot water on demand and require no cylinder storage. The flow rate is also much higher than that provided by a traditional combi boiler and therefore those living in the dwellings can enjoy a better quality of life. Heat Interface Units can also help to reduce the level of ongoing maintenance and investment costs. Instead of supplying gas to each individual apartment and installing a domestic boiler in each, heat interface units only need a single hot water riser to be connected to each apartment and the central boiler plant and this results in a significant saving. Because there is also no need to install a gas network across the entire building, installation and maintenance costs are reduced. Installation of HIUs is also easier than installing a traditional boiler, with no need for flues, ventilation routes or gas training qualifications for the installers themselves. This means that maintenance can be carried out by personnel who are not gas qualified which is a lot more convenient.

Cleaning And Flushing Heat Interface Units

Although Heat Interface Units require less on-going maintenance than some other types of heating system, it is still important to carry out regular cleaning in order to ensure that the system functions to its maximum capacity. Over time, debris and contaminants build up inside the system and this can result in reduced efficiency, higher energy bills and poor quality of heat. By power flushing the main system itself and carrying out separate flushes for each of the housing units, it is possible to ensure that the complex’s heating and hot water system operates efficiently and effectively, enjoying a longer lifespan.