From the Revd David Gibson
Sir, - The impressive geothermal heating system at Manchester
Cathedral (News, 25 October) will work
best if pipes have been introduced into the ground rather
than piles. The fluid pumped through these pipes will then extract
low-grade heat from deep underground, to be converted into usable
heat by heat pumps.
DAVID GIBSON
13 Rose Hall Gardens
Bungay, Suffolk NR35 1BJ