Well, I was only there for 33 hours, and I never got further than a very small part of Glasgow surrounding the exhibition centre, so this is obviously not a review of Scotland as such, but I did talk to a lot of people and heard some fascinating stories.
I was approached by two sets of people commissioning Passive Houses, one couple in Aberdeenshire, and a man called Ian who is involved in a plan to build 6 at Findhorn. Passive House really does seem to be in fashion now - lots of people have heard of it and it's gradually moving into the vernacular, although I am still not convinced everybody understands what it really means. The couple from Aberdeen wanted to know the best way to heat a Passive House, and I said I thought the jury was still out but that many people's old favourite, the wood burning stove, would probably blow a hole in the airtightness requirement. Anyone else any thoughts?
I met a couple who run a very proactive Project Management company called Quantum Forth. I was impressed by the service they offer.
And I caught up with Charles Stewart of SIPS Industries whose boundless enthusiasm never ceases to impress. The guy now has SIPS plants in Western Australia and South Africa, as well as his original business in Fife. Charles hails from Zimbabwe and is still very active in raising money for schools in southern Africa, and is also planning to fly across Africa in an Autogyro this summer. Check out Heli2Africa.
Perhaps the best story I came across was a Mr Disgruntled of Edinburgh who is planning to undertake a flat modernisation in that fair city. The job involves putting in an en-suite bathroom and he is in dispute with his building inspector who is insisting that the door is wide enough for wheelchair access, which, for one reason or another, renders his en-suite bathroom unviable. It just so happens that the bedroom door — which you need to go through to access the bathroom — isn't this wide (but then it's already there). And the flat just happens to be on the third floor and there is no lift. But will the building inspector yield? No way. The new door must be compliant. It's good to know that common sense is as thin on the ground in Scotland as it is elsewhere.
"The couple from Aberdeen wanted to know the best way to heat a Passive House, and I said I thought the jury was still out but that many people's old favourite, the wood burning stove, would probably blow a hole in the airtightness requirement. Anyone else any thoughts?"
ReplyDeleteAt the risk of seeming ignorant isn't the whole point of a Passive House is that it doesn't require heating?
Absolutely not. The key metric is that it only requires 15kWh/m2/annum for space heating. If it didn't require any heating, this figure would be 0kWh/m2/a. The question is "How is this 15kWh/m2/a best delivered?"
ReplyDelete"the wood burning stove, would probably blow a hole in the airtightness requirement. Anyone else any thoughts?"
ReplyDeleteNot sure about that. We installed a 4kW stove in our 'airtight' SIPs house. The airtightness test was the best (by a long way) the engineer and the building inspector had seen (below 2 whatever the units are). As the stove is less than 5kW it needs no airbrick or any independent air supply. It works fine, lights & burns easily.
Steve,
ReplyDeleteI have no doubt that this sort of arrangement works - indeed I think you may have already explained your system in some detail to me if you are the Steve L in Haworth that I am thinking you are! But a regular SIPS house isn't a "Passive House" which requires an airtightness score of 0.6 or less.
Which brings us full circle back to an unresolved issue, as far as I can see. Which is that it may be better to build a near Passive house which is heated by a wood burner (distributed by MVHR), than an actual Passive House which requires electric heating.
According to Wikipedia - so it neds checking - the heating required is in the range of 800 to 1,500 Watts, and then only on the coldest days. So a 4Kw stove would provide much more heat than required, and wouldn't be very controllable either, potentially leading to overheating - then, I suppose, opening the windows or using more electricity on the MHRV to remove the excess.
ReplyDeleteAnyway, far more energy would be used heating the hot water than in heating the building, so perhaps heating that with a wood pellet boiler might be a better solution (as a back-up for solar, of course). Some of the water could then be fed through a heat exchanger in the ventilation duct on the few days when its required.
Maybe a house warming party would be the answer...
ReplyDelete