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guydewdney
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« on: November 16, 2009, 11:09:41 PM » |
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Mum has bought a smallholding (15 acres, Somerset).
Current house is 1930/40? extended upteen times badly, bungalow.
Current plan is to knock down south face of house, and re-build face with mostly glass (sort of passiv haus) - then an extension the same size as a new build, doubling the size of the house - again mostly glass on the south face.
No gas in the area.
Hill top location - but neighbours locally - so wind probably out.
No water :-( so hydro out.
the question is:-
Heating - she seems to want GSHP - but as has been pointed out - you are converting the most expensive form of energy (leccy) to heat. I assumed that a bale / log batch boiler would be better. She's in her 60's - but fit and agile. Hubby is similar. They are not overly happy about lugging logs about....
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billt
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« Reply #1 on: November 17, 2009, 08:27:50 AM » |
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If they can get the insulation levels up and use a heating system with low water temperatures (UFH or very large radiators) I'd say that a good GSHP is a reasonable solution. I completely understand their lack of enthusiasm for all that manual handling, and, if they haven't got wood themselves, that could get expensive.
Overall efficiency of a good GSHP system properly run should be about the same as burning fuel directly in an efficient boiler and the running costs should be similar to mains gas.
I'm not really a fan of heat pumps; I think a lot of salesmen exaggerate their efficiency, if power fails your heating system fails, it adds an unnecessary process between burning the fuel and using it and it adds undesirable load to the grid. But they are a good solution in some cases and this sounds as if its a good example.
If they go for GSHP they'd want a good solar thermal system for hot water so they don't have to use the heat pump in its most inefficient mode.
They're going to do so much work on the house, may be it would be worth rebuilding completely with very good insulation and reduce the heat demand to almost nothing. Of course they probably don't want the aggro, or don't have the resources for that.
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welshboy
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« Reply #2 on: November 17, 2009, 10:03:10 AM » |
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Hi Guy,
We used to have a large conservatory SE facing in our last house. The thing would overheat rapidly in the usable period which was Valentines day to Guy Fawkes but in the winter was useless.Perhaps not totally useless other than storage and a form of insulation for the stone walls.
If starting from scratch with a south facing property I would go for
2 lots of pipework for underfloor heating .
1 would be for gshp
1 wold be for solar. This second set of pipework would be heated from a trombe type wall with pipes embedded. Could even have some pipes embedded in tarmac drive/concrete patio.
Loads of insulation under the floor and the building perimeter paths laid with pumice concrete as the base - 15 times more insulation value than normal concrete.
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renewablejohn
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« Reply #3 on: November 17, 2009, 10:12:56 AM » |
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Guy I would just go for a swedish house with mechanical heat recovery. The insulation is so good you would not require a heater but for the rare occasion or as a focal point have a pellet stove. http://www.scandia-hus.co.ukWe were going to buy one of these 15 years ago and even then they had triple glazing while everybody else was jumping on the double glazing bandwagon. |
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« Last Edit: November 17, 2009, 10:16:04 AM by renewablejohn »
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brackwell
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« Reply #4 on: November 17, 2009, 10:22:21 AM » |
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Unfortunately they will not always be 60 and fit and agile and putting the GSHP in when the digger(an expensive part) is already there seems a good solution.
We already know about insulate,insulate ..... but with so much modification/expansion it must ask the question of rebuild but no doubt you/they have thought of this.
I dont suppose they take extra long showers so what about a solar thermal panel feeding a inline water heater. The heater will get little use ( if you keep the tank smallish ) but is always a guarantee. Perhaps not the best if they are bath people.
The all glass south facing wall needs to be built with a specific amount of roof overhang or you will get too much thermal gain in summer. My house has this feature and would recommend to anyone.
Ken
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dhaslam
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« Reply #5 on: November 17, 2009, 11:41:47 AM » |
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There could be some problems insulating the existing building, particularly the floor, it might be better to knock it all down and build exactly to requirements. Solar gain is very important but the south facing windows have to be shaded to avoid overheating in summer. I am getting temperatures in the sitting room which is central in the house and south facing of between 20C and 23C most of the time with just solar and passive heat. However in the evening it it is nice to turn the thermostat one degree over the current temperature to have a warm floor. Bathrooms, even if the air temperature is low, can feel very comfortable if the underfloor heating is on for an hour or so before use. A very small stove would be useful in winter as a focal point and to top up DHW water temperatures but a stove can over heat a well insulated room.
A ground source heat pump should be fine as the main heat source. The buffer tank and the size of pump needs to be adequate to only use off peal electricity. The buffer tank should be built into the core of the house so that heat loss is contained in the building. It should be possible to heat a well insulated house as well as DHW preheating for about £1 per day, using off peak electricity.
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guydewdney
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« Reply #6 on: November 17, 2009, 03:37:20 PM » |
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Unfortunately they will not always be 60 and fit and agile and putting the GSHP in when the digger(an expensive part) is already there seems a good solution.
We already know about insulate,insulate ..... but with so much modification/expansion it must ask the question of rebuild but no doubt you/they have thought of this.
I dont suppose they take extra long showers so what about a solar thermal panel feeding a inline water heater. The heater will get little use ( if you keep the tank smallish ) but is always a guarantee. Perhaps not the best if they are bath people.
The all glass south facing wall needs to be built with a specific amount of roof overhang or you will get too much thermal gain in summer. My house has this feature and would recommend to anyone.
Ken
Ha - yes - the planners wont let them knock it down, and build something nice - they have to keep the existing building to keep the permitted development rights. Crazy. Mum takes huge gert baths.... He has a power shower! Loads of solar going in. Will ask about overhang for glass. |
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renewablejohn
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« Reply #7 on: November 17, 2009, 03:50:50 PM » |
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guy Sign up to be televised "Grand Design" Submit green plans to council, Turn up at council planning meeting with camera crew and hey presto plans passed.  Or is it not supposed to work like that.  Seriously get a good land agent if your farm is over 5 hectares then the council will find it very difficult to refuse a new build and knock down of the old as the accommodation is required as part of the farm. If the building was listed then it would be different. |
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« Last Edit: November 17, 2009, 03:57:38 PM by renewablejohn »
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brackwell
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« Reply #8 on: November 17, 2009, 05:16:05 PM » |
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I agree with renewable john a friend of mine did just that making the volume,i think 40% bigger under permitted development rights ! Ken
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martin
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« Reply #9 on: November 17, 2009, 05:32:48 PM » |
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Dealing with reticent planners - Tactic 1 - "the cr*p bulldozer driver" - you employ a bulldozer driver to help with your work, and he "accidentally" knocks down something major and structural........oh dear, what a shame, never mind! 2) You have the new (far too small) plans agreed, the inspector pops round, measures up, and ten minutes after he's gone, the silly sod with the bulldozer pops back, has another unfortunate accident, and the walls are rebuilt next day in a slightly different (by at least 10') spot..... 3) If 1 and 2 are ineffective- The brown envelope/holiday/car/membership of cherished golf club/brotherhood...........  |
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Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk |
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guydewdney
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« Reply #10 on: November 17, 2009, 05:50:57 PM » |
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They have had meetings with the head of planning - who catagorically stated that if they knocked it down, they could only re-build to the same volume. If they extend it - they can increase by x% (40 or 50%) I said - why not knock up a bodge house increasing the current volume by 50% - then bulldoze the bloody lot, and re-build to the same volume as the previous bodge build? Thats out of the question...  They have professional planning getter types working on it... |
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martin
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« Reply #11 on: November 17, 2009, 05:52:54 PM » |
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that'll be a variation on tactic 3 then!  |
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Unpaid volunteer administrator and moderator (not employed by Navitron) - Views expressed are my own - curmudgeonly babyboomer! - http://www.farmco.co.uk |
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desperate
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« Reply #12 on: November 17, 2009, 07:45:11 PM » |
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Guy If your folks are undertaking such a large project, why not lots of solar thermal and an interseason store, Noelsquibb likes digging holes so I am told Desperate |
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daftlad
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« Reply #13 on: November 17, 2009, 09:42:27 PM » |
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Don't forget thermal mass if you are going to put in so many south facing windows, maybe a masonry stove could be part of that thermal mass?  see ya |
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I WILL KEEP BANGING ON ABOUT MASONRY STOVES
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guydewdney
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« Reply #14 on: November 17, 2009, 09:47:41 PM » |
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I WILL KEEP BANGING ON ABOUT MASONRY STOVES
LOL
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