Task: Drilling – update
Drilling continues at a pace having completed seven boreholes to date, and another two being drilled on day eight. Two of the twelve ground arrays are now completely drilled totalling 837m.
Once the borehole is drilled and flushed the 40mm pipes are added using the telehandler, lowering the pipe in from directly above whilst weight bars are fixed to the pipes to help the process.
An extra pipe known as a tremie is fed to the bottom of the hole, this is used to grout the hole from the bottom to the top filling all voids. The mixed grout is pumped under pressure to the bottom of the borehole. The thermally enhanced grout is mixed using sand and bentonite, the target for the mix is 1.78W/mK or greater to ensure that the ground array is kept within design conditions.
Project in a nutshell
- Design and install communal ground source heat pump systems into two blocks of three-storey flats
- Drill 40 boreholes to an average depth of 140m
- Manifold the boreholes to 12 individual ground arrays
- Trench back to the 60 flats
- Remove old inefficient night store heaters and hot water cylinder
- Replace with a Kensa Shoebox 6kW, a highly efficient hot water cylinder and a wet radiator system
- Install thermostatic and time controls to allow total control for residents with individual heat requirements
Read more about the background to this project here: http://www.kensaheatpumps.com/live-retrofit-project-blog-follow-trent-doves-latest-gshp-scheme/