We have finally settled on a design of connecting up all the earth tubes and getting the air in and out of them! We have 12 tubes all together, each one being 150mm (6inches) diameter internal) in order to provide time for the air to exchange its thermal energies with the surrounding thermal mass! The 12 tubes is equivalent to a single 600mm (2feet) diameter pipe!
After consulting with our friendly structual engineers, who advised us that our original design of using concrete blocks to construct a chimney and tunnel to pass the air down to the tubes, has potential problems at the joins due to the loading pressure from all directions but especially the sides, at 2.5m (8feet) depths! They advised the use of pre-casted concrete pipes segments to make the chimney and tunnel / chamber but this lead us to realise that we could route the tubes themselves upwards with 90degrees corners and terminate them inside the buildigs! This makes it so much easier and avoid mssing around with concrete blocks, pouring concrete around them and other reinforcing methods or drilling holes in the sides of concrete pipes!!
So Many Thank goes to our engineers at Burrell Partnerships of Norwich!!
