It seems to have been a long time since we began to install red pipework throughout the house as part of the mechanical heat recovery system. The details are given below in italics but this system allows all of the air coming into the building to be warmed by the air going out. The rate of flow is controlled and is set at a level which means that we need no other ventilation: no trickle vents in the windows; no other extraction fans; and no air bricks. Unfortunately the wrens and robins which currently roost and nest in the air vents in our mobile home will have to find alternative accommodation!
Last year we tied ropes around the 65kg heat exchanger to enable 4 of us to carry it up the stairs. This was quite a struggle and we then spent a considerable time trying to devise ways of raising it right up to its planned lofty position. Eventually we discovered that it was possible to take it apart and found that the two separate pieces were actually quite manageable!
Now we have finally installed the flexible, silver-clad insulated ducts which connect the distribution boxes to the heat exchanger, thus completing the system. To our great relief, the ducts just fitted in the very limited space which we had available. Another job can be ticked off our list!
We had delayed making this final connection because the white plastic pipework of the central vacuum system also needed to traverse the area. This carries dust and debris from 4 wall-mounted vacuum cleaner sockets to the static vacuum in one of the wardrobes. This central vacuum system is ideal for those of us with asthma as all of the exhaust air is channeled straight out of the house without reaching our nostrils or blowing other dust into the air before it has been vacuumed up.
Once again the Wikihouse build system has shown us its benefits and its challenges. The hollow plywood walls were ideal for feeding the vacuum pipes through vertically, but our structural engineers had advised against drilling any holes in the 9 frames which form the structure of the building. Therefore the main horizontal pipe crosses the house just beneath the ceiling which is above the top of the stairs and hallway and is hidden by the rolled-over plasterwork.
The details of our heat recovery system: 4 red pipes, from the kitchen, utility room, downstairs wetroom and upstairs bathroom, connect to one of the two distribution boxes located in a void above the entrance to our spare bedroom. Once the electrical supply has been connected, the warm air from these 4 rooms will be driven through a third box – the heat exchanger – before travelling along a large black pipe to the outside.
Incoming air will travel along a second black pipe, through the heat exchanger to the second distribution box and will be delivered, via more red pipes, to the remaining rooms.
The 2 sets of air never mix, but they pass either side a large, thin, metallic surface which conducts the heat from one to the other.
Central vacuum with exhaust to outside.
Black heat recovery pipes, white vacuum cleaner pipes.