So now the scaffold is down we have unfettered access to the outside of the house and can bring the ground source heat pump loops inside. The 32mm groud loop pipe has to be sleeved with closed cell foam for the last few metres as it approaches the house because it will be running at well below zero on the return side and could freeze the ground or any water pipes near it. Each 2 metre length of “Armaflex” is glued to the next with contact adhesive applied with a brush. You must use Armaflex because other plumbing products are not closed cell and will allow water into their structure which will freeze. Armaflex is available as a tube or a tube with a slit down the side. It is better to use the version without the slit and slide it on before you pass the pipes into the house if you can organise this.
We also decided to give some mechanical protection to the Armaflex by sliding 85mm land drain pipe over it. Not the easiest of jobs due to the natural curve in the pipe and in the end we cut the 3 metres of pipe we needed into three bits to slide each one over.
