I've been trying to interest the boss in a whole house heat recovery unit for the old coach house we occupy as offices. Bearing in mind 15 of us lounge about there most of the day and manage to consume 80 units of electricity with PCs, shredders, kettles, microwave ovens etc and a lesser amount for gas I was a little surprised at the potential for savings compared with the other measures I've taken ( 65mm celotex drylining,
100+65mm celotex warm roof insulation. 50mm celotex under floor screed and new DG throughout).From my initial workings:
I need 36000litres/person/hr which is about 45kg/person/hr with an average difference in temperature from ambient of 10C and 15 people in occupation for around 10 hours I make that 18.75kWhr(t) needed to heat incoming fresh air with a cost of about GBP0.65625. Even if I get 50% of that heat back I'm not going to make much of a dent in our energy spend.
Have I made a wrong assumption or mistake?
AJH