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Chris
Thanks. IDHEE site says “experiments are underway” but couldn't find conference program.
R4 early this morning featured a dairy farm in Dorset building a methane digester of German design and program said that in Germany they would feed bio-methane into the gas grid, not generate electricity at 30-35% efficiency. Gas output of farm mentioned would be about 1000 kW.
David.
It still might be worth doing. As much solar energy is available from say mid-February to late March as from mid-September to late October and even a Passive House still needs some heat in this period of spring.
As I said, electric backup may cost the homeowner next to nothing but each kWe of extra coincident peak demand costs many £1,000s in power station costs and grid reinforcement costs. What “makes sense” to an individual may not make sense to the UK and should not therefore be encouraged by Building Regulations or grant programs.
David.
Mark
Yes, I agree re. the need to make this clear if AECB gets outside support to write a more detailed/watertight version.
Those involved in the R2000 standard agreed that any combustion appliance with a conventional flue (this would include all wood-fired boilers) is at risk of backdraughting if a building is tight and uses exhaust ventilation. As usual, balanced flue gas/LPG/oil boilers (or possibly in future the same burning biofuels) give less cause for concern as they don't depressurise the house and interact with a MEV system.
It's possible that some ordinary UK homes are airtight enough (by accident) to cause health problems if they have an unflued appliance. A CO detector next to the woodstove or fireplace might be a good idea. Spillage is most likely when the fire is dying down, not when it's at full throttle.
David.
Mark
Have you tried THERM? Free from the USA, thanks to their enlightened Dept of Energy (Lawrence Berkeley Laboratory, Univ of California).
I used to use FRAME – free from Canada (written by Enermodal Engineering for the govt.) – but may have been overtaken by THERM. Was very user-friendly though.
David.
I've never heard of this co. but they probably quote this U-value for the centre of glass and ignore the frame and edge of glass. A typical economy with the truth I think. Whole window might be as high as 1.5 or 1.8.
David.
These are not the only two actually. You can also get top-hung (usually reversible) and pivoting. Windows in the rest of Europe aren't all tilt and turn – one finds a wide mixture.
Side-hung hinges don't usually permit a 1500 x 2400 mm opening light as some T&T hinges do. So you end up with more mullions, less solar gain and more heat loss.
David.
Mark
Sorry – 1995 was the paper age and CIBSE hasn't digitised its past publications at all.
David.
Mark
If you can get hold of the paper by me and Dr Bob Lowe in the 1995 CIBSE Conference Proceedings, we suggested such a holistic approach and also put forward the concept of effective window U-value (including the thermal bridges due to the installation.)
David.
Yes I got it too and they wasted 10 mins before asking for dosh.
D
For backup, use a storable fuel. Electric backup still leaves the same coincident peak demand, it just reduces the load factor, so is very bad from overall system point of view.
D.
Mark
It's very important actually. Optimising the fenestration for fewer, larger windows (near the limits of a manufacturer's technology) may reduce the heat demand of a new house by more than putting an extra 50 mm of insulation on the walls or roof. Also it can do this for negative cost – not added cost. My hunch which is unproven is that conservatories (people usually put radiators in them, using more energy per m2 than the rest of the house) would be less common if modern houses had (a) larger windows and (b) more generous floor areas.
David.
Mark
It's not so easy to remove the thermal bridging which is caused by the frame. The area of wall where the external insulation overlaps over the front of the window frame doesn't have the same low U-value as the rest of the wall.
AFAIK the Hanover House which I wrote about 10 yrs ago had Canadian fibreglass windows same as my house.
Someone needs to do the modelling in PHPP. I started but have too much else to do.
David.
Mark
On a current project, a new house actually, the M&E engineer wanted underfloor heating *as well as* the plumbing coil. This was felt to be OTT. The insurance policy, if there is to be one, is likely to be two blanked-off pipes so that the area in question (very heavily-glazed) could in future be fitted with a tiny radiator if need be. However, the design of that area of the building is subject to revision and if so the insurance policy may not be used.
Another project fails to achieve the 10 W/m2 despite good U values and needs three small radiators in addition to the warmed air.
HTH
David.
YOU MUSTN'T DIM NORMAL CFLs. (They come with a warning.) I suggest taking them out immediately.
The mechanism which is used to dim fluorescent lamps (high-frequency ballasts only) is different from the mechanism used to dim incandescents. The equipment needed is also different – and so you won't be able to just plug them into an existing incandescent socket.
HTH
David.
12 February 2007 at 4:31 pm in reply to: Cold bridges at the founds/ground slab interface and Sleeper walls #33547Mike
Yes; the published details refer to situations which may be applicable to “fairly advanced self-builders”. The AECB guidance is more focussed on trying to meet the U-values of 0.15/0.25/0.2/1.5 as in the Silver Standard (NB the 1.5 includes impact of thermal bridge between window and wall) and showing what the thermal bridges are.
David.
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