HIU - how do they work?

[WC1]

I believe it's essentially a heat exchanger. Communal hot water is used to heat domestic hot water.

 

[Knappers]

I miss doing commercial work, I remember the first boiler that I serviced by suiting up and walking into with a broom to clean the chamber and circulating pumps that you lift into place with an engine hoist - proper work!

 

[alclark]

I'm just curious really. I did do a quick calculation based on 1500 apartments with the same heat loss and DHW requirements, plus a rough loss through pipework and it was like you say megawatts. I did have a quick Google on size of pipes required to carry this power but wasnt very successful. Like I said my experience is only on domestic properties, I would love to experience larger systems and definitely want to gain experience with commercial and industrial oil fired appliances. I'm not gas trained, oil is all we ever did.

they break it down fairly well here - full list of HIUs available