40kW gasifying log burner and 10 sq.m of solar thermal collectors both feeding into heat stores providing space heating and hot water.
The boiler the house came with was so arthritic no engineer would touch it. Manchester is a smoke control zone. The only kit with the DEFRA exemption was either too big or eye wateringly expensive or both, and its fuel – pellets was mostly shipped in from abroad, slightly denting the low carbon credentials. Sundance Renewables – a co-op in south Wales introduced us to the Atmos gasifying log burner. It burns logs, sucking the flames into a chamber beneath the logs which ensures a very hot clean burn with minimal ash. We got hold of the test data and it is well below the threshold for exemption so after 18 months we talked the smoke control officer into letting us install one – although with the caveat that he has the right to insist on its removal if he gets complaints. It does emit smoke, but only really an issue for the first half an hour then it calms down and the whole process of a burn is finished within 2 hours anyway, all the heat is dumped into 2 water tanks – thermal accumulators. They both have solar and hot water heat exchange coils in them. Cold water is pre-warmed in the lower larger tank first, then taken up to full temperature in the upper one. In summer the solar panels feed into the top tank first then when up to top temperature feed into the bottom. In winter they feed into the cooler lower tank. The top tank made by Consolar also has syphons in it that help make sure the store stratifies so that even when the heating draws hot water from the middle of the tank the top where the hot water is drawn through remains hot.
We had alot of help with designing and fitting the system from Richard Drover and also from Greenshop Solar, who sold us the control system.
We have put as many panels up as we could fit neatly to minimise the amount of wood we’ll have to burn. There are 80 tubes in 4 arrays running the full length of the ridge with a thin access walkway running beneath them that both masks them from the street below a little and allows safe access. These are the cheapest well reviewed ones we could find from Navitron on the basis that with so much water into which to put the heat we do not need expensive methods of dealing with overheating. We have an added overheat protection of an old radiator from the top of the house plumbed behind the stored wood in the cellar so that spare heat can be used to dry wood further – needless to say in a Mancunian summer there was only 1 day when it looked like it might divert from the 2 tanks to this.