Lifting the lid on an HIU

Heat Interface Units (also sometimes known as Heat Boxes and Consumer Interface Units) basically fulfils the same function as a gas boiler in a property when used as part of a communal heating network. Each home or apartment has its own HIU installed, which uses heat distributed from the central network to provide heating and domestic hot water (DHW) – completely replacing the requirement for individual boilers in each property. To the end user it’s just like having a boiler as normal but without the flame. Our units are extremely compact in size and will even fit into a standard 600mm cupboard unit.

At Mibec we sell a range of Heat Interface Units (HIUs); however not everyone will be familiar with their inner workings and the advantages they can bring. This short article gives a quick run through of the key components inside our new Hiper HIU:

Plate Heat Exchangers – two plate heat exchangers one for heating (CH) and one for hot water (DHWS).the plate heat exchangers are extremely easy to access from the front and unlike many boilers can be removed for cleaning in seconds by the service engineer.

Circulating pump – The unit comes with a high quality, proven and reliable Wilo pump for the central heating system. The product is low energy Erp (Energy Related Products) compliant.

PID Control Unit (Proportional Integral Derivative) – maintains the efficiency of the HIU. Provide stable temperatures under varying load conditions. Unique algorithms constantly recalculate the amount and the speed of modulation required for maximum efficiency.

Integral PIC valve (Pressure Independent Control) – with electric actuator giving proportional modulating control as instructed by the PID Controller. Unlike many other HIUs, further control valves (for example Differential Pressure Control Valves) are not normally required.

Expansion vessel – a small tank used to protect the closed (not open to atmospheric pressure) water heating systems and domestic hot water systems from excessive pressure.

Strainer – uniquely design strainer with increased surface area for longer operation without blocking or reduced performance over a standard pattern Y Strainer.

Pressure Controls – includes a low pressure switch will stop the circulating pump should the secondary system drop below 0.7 Bar. The HIU is fitted with a Safety Relief valve set at 3 bar for high pressure protection.

Insulation – the HIU panels are all fully insulated including the backplate to prevent overheating of the surrounding area.

Metering – prepayment billing can be accommodated with an accessory kit to shut down the unit when the tenant is no longer in credit.

If you would like to find out more please visit our Heat Interface Units product pages where you can download our latest technical brochures. At Mibec we offer a full free of charge specification service covering the whole of the UK, designed to support architects, specifiers or contractors, helping you to select the right heating solution to meet your needs. Please feel free to email or call our support department on 01948 661639 where one of our highly trained advisers will be happy to help you with any HIU or communal heating queries.