For properties with multiple buildings to heat or groups of houses where individual residents connect to the same heat source – a shared facility for distributing heat results in lower energy bills per property with lower maintenance costs.
How does it work?
District heating works by having only one boiler room; the size of the boiler depends on the total combined heat load of the buildings to be heated and we can install systems up to 1 megawatt.
From the boiler room, a heat main carries hot water to every building that it is connected to the system. It has a flow and return pipe exactly the same as you would find in a conventional heating system.
Hot water is distributed to the individual buildings where it cools and then travels back to the plant room to be re-heated by the boiler and sent back out.
Networking heat requires a plate heat exchanger (PHE) at each building instead of a boiler. This gives an indirect heat transfer between the water in the heat main and in your heating system. The PHE is much smaller than most domestic boilers and will normally fit in exactly the same spot meaning there is very little need to alter the pipework inside the property.
There are many different ways to connect each building. Generally, we either bring the heat main up inside the building underneath the wall and foundation, or to the outside edge with special elbows to connect through the wall above the damp proof membrane.
We use CALPEX heat main, selected because of its excellent thermal and mechanical properties. It is also corrosion-proof, chemically resistant and free of harmful substances, making it exceptionally environmentally friendly.
The heat main is typically set in a trench at a depth of 900mm. At the bottom we use an aggregate like pea gravel for drainage. We then lay a bed of sand on top. The heat main is laid, along with any additional ducting for control cabling – it is then covered with more sand until it is no longer visible. Once this is done, we refill with the spoil that came out of the trench. Any leftover spoil is removed from site.