The cold return pipework on the comfort cooling system needs to be insulated. So conventional plastic 125mm diameter pipework gets  a sleeve made of thin bubblewrap with metal outer skin slipped over it. Joints are taped with the self adhesive metal tape used for a variety of ducting work on houses.

Here you can see one pipe coming into the ceiling of a bedroom, and another pipe on it’s way down to the lounge. This pipe will be hidden in a “fitted cupboard” as will the warm air pick up from the lounge which is at the other end of the cupboard.

You can also see the white overflow pipe which goes up to the chiller to allow any condensation in the chiller to be removed. This has a small trap (u bend) under the chiller. 

 There was just enough space in the eaves to fit the heat recovery and the comfort cooling units. The comfort cooling unit on the right re-cycles air in the room, passes it over a heat exchange matrix which uses the cold return feed from the heat pump to reduce the air temperature by about 7 degrees. So the return side of this has to be insulated (the sliver stuff). The heat recovery pipes only have to be insulated where it goes into “cold” spaces such between the rafters above the sheepswool insulation.

 One of the options that attracted us to the Ground Sourced Heat Pump was that you could also use the return feed of cold water to cool the house in the summer. Although 2007 and 2008 have hardly been blistering summers, only three years ago everyone was talking of summers getting hotter and hotter. So two comfort cooling units were added to the heat pump order to cool bedrooms and the lounge.

But having decided to fit a heat recovery system since we bought the comfort cooling units we have to think about how we duct the whole system. After considerable discussion with those in the know, we have decided to duct the comfort cooling system separately. The Heat Recovery system has a “summer bypass” that is a thermostatic switch which cuts out the heat recover element if the ambient temperature goes over a certain level and we will set the comfort coolers to cut in at that same point – hopefully!

Of course all this means our super tilt and turn windows and trickle vents will be unnecessary and the idea of living in a house where you do not need to open windows is not going down well at present. Only by living with it will we see how it performs.