..... Another problem that can arise with very high levels of insulation and a well sealed house, is large amounts of condensation. In Scandinavian new builds I've seen this has been specially catered for.
El cheapo eh.
It is not!!!!
...insulated well below Germany, Scandinavia, north America and most of western Europe.
Go for 0.1ish
Precisely, and at a certain point negative returns are achieved.
In other words, when the last x mm of insulation takes more energy to manufacture, distribute, install, and eventually dispose of than it will ever save over it's expected lifetime, then it has a negative overall environmental impact.
This cutoff point will also be influenced by the average weather conditions of the locality. Those advocating movement towards insulation standards common in Germany, Scandinavia and parts of the North American continent should remember that they suffer much colder winters than the majority of the UK which will therefore push the environmental equilibrium towards installation of more insulation.
-- Richard Sampson
email me at richard at olifant d-ot co do-t uk
Nice try, but flawed logic. The cut off point is when you don't require a full heating system. That is simple. Then the gains start to really add up. What is not really taken into account is the cooling effect insulation can have in hot summers, which appear to be on the way. So, the gains, especially in comfort conditions in winter and summer, increase yet again.
Insulation to the point of not requiring a full heating system is a win, win situation all the way. All the knowledgeable experts who write on this subject all agree that superinsulation is well worth it.
Don't guess, find out.
It is safe to assume you will still want hot water, hence you still need a boiler. Yes you can fit fewer or smaller radiators but that does not represent much capital cost saving (given that you can install a full heating system for under 3K - you may only save 1K capital outlay). You seem to be recommending spending several times that cost in PIR foam alone before you get onto ventilation with heat recovery. It may take a lifetime to recover the capital costs in reduced energy usage.
Sorry - but this is nonsense. No amount of insulation will have a "cooling effect".
More insulation will reduce the rate of heat gain inside the house, but will also ensure that once it has gained the heat (which it inevitably will) it will be harder to dissipate it. It will only take a few days of hot humid weather to get the inside of the house unpleasantly hot - no matter how well you insulate it. You still need windows (which are not going to have u values of 0.1), you still get solar gain, and you still need to open doors to get in and out of the building, allowing air changes.
Not if you reach the point of never recovering from the environmental impact of building the thing, during the lifetime of the property. Not if you never recover the capital outlay in lower energy bills.
Where "knowledgeable" = supports your point of view no doubt?
You can generally find experts who will support any point of view you choose, so this is not really adding any weight to the argument.
Maybe.
£3K please get real. In a small terraced house, yes.You can do it with PIR foam, or a mix. Using PIR foam on the outer to reduce thermal bridging and cheaper insulation on the inside.
Nonsense. With a boiler you need annual servicing, assuming you get a pro to do it. With electricity you do not require servicing. Assuming a new build, or an extensive renovation, it is worth going all electric as the capital installation costs are far lower. With a superinsulated home the DHW cost will exceed the heating cost, so having roof solar panels to fully heat, and pre-heat, the DHW will reduce electricity running costs. Electric heating appliances are cheap to buy and install and not annual servicing costs.
In a superinsulated home, a partial electric heating system (which will be rarely used) and DHW backed up by solar heating will highly cost effective.
It keeps heat out and well as in, hence a cooler house. Very simple to understand.
The UK cools at night, so opening windows will disipate heat and the heat flow also will reverve from inside to outside through the walls
Stop making things up. Do some research. Many eco homes cost little extra, if at all to build in the first place. You have to get the design right, which is not difficult.
Do some research. Do some reading. Stop trying to be clever and making things up. My piont of view is based on hard facts, not a whim of a theory.
What a silly statement.
Well, sort of. But .............. Here in Canada with longer colder winters (and often heat leaching winds!) higher values of the insulation reduce heat loss and therefore the cost of heating ones home. Since the energy cost increases of the 1970/80s etc. much thicker insulation has been the 'standard'. Most wood frame houses now have
6 inch wooden stud outer walls filled with insulation and/or sheeted with foam boards, older homes 4 inch. But it is the 'vapour barrier' on the warm side of the insulation, whatever type and thickness it is, that is important. It prevents the warm air from seeping out into the outer walls and ceilings. Warm air is moist; when it cools down the moisture in it condenses into water and can cause rot, mould, damp/wet insulation and even condensation and water droplets in the attic. (Saw one roof where every nail in the loft/attic was rusty!) same thing, on a smaller scale, as occasionally happens in large stadia.during a temperature change. i.e. "It rains indoors". From time to time our National Government has provided incentives to increase insulation values, typically and easily by adding several additional inches to ceilings. Often easy to do using 'blown in' insulation. But emphasis is always on proper installation, adding to and not blocking off attic air circulation vents and stressing the use of proper vapour barriers and or/sealing leakage up into the roof space. An improper or missing vapour barrier in the ceilings and no attic ventilation can spell expensive major problems. See damp attics and peeling painted trim! One guy had 'mushrooms' (fungus) growing up there! Most new Canadian houses now to qualify for mortgage, are built to R2000 specification; this does require a 'sealed' vapour barrier house with extensive use of sealants around all interior wall apertures. That type of construction therefore requires an air/heat exchanger system which runs continuously using AC mains and also careful additional ventilation of bathrooms and cooking areas. Both my daughters houses each about 1500 sq. feet per one floor plus a 'full basement' are built to this standard are electrically heated and are very economical and comfortable. Efficiencies of up to 80% heat recovery are claimed for the air/heat exchangers but personally I doubt if that is true over a wide range of temperatures. Not having an air exchanger in this older more 'leaky' and less efficient house am not familiar with their operation in detail. They do produce condensate which is drained away by a tube and do need cleaning of the filters and heat exchanger core fairly often.. (How much water vapour does a human breathes out during a typical night? A litre or two? By the way, misunderstandings persists about not allowing the house humidity to get into the outer walls of older homes. Consequently one hears a lot of nonsense about 'Not being able to keep paint on my house", among older folks who built houses in the older traditional way. As to why paint blisters and peels on the outside lapboards of a painted house. What's happening is that without vapour barriers and or adequate ventilation moisture condenses as it meets the cold 'within' the exterior walls and then pushes the paint off! Houses finished with permeable stain permit that moisture, some will always occur, to 'breathe' out through the walls. This approach has worked for us in the two houses we built and have lived in ourselves since 1960. Some older houses that have been covered over with nice looking? but impermeable siding, such as vinyl, have suffered some rot within the walls! My neighbour had to replace most of one end wall of his less than 25 year old house!
It also makes the house air-tight reducing much heat loss in winter, and gain in the summer. The Canadians have the R2000 standard, which is one the most advanced in the world, if not the most. The Canadians, say "build tight, ventilate right".
The Canadians don't just slap up the VCB, as they do here. It is meticulously installed and properly taped up. The Canadians are implementing the R2000 standard in the UK and Japan. Canadian companies harve be involved with Uk companies, as the Uk companies just don't have the skills levels, or can concenrrate long enough to carry out detailed work.
impermeable
A lot of issues here which I'm not qualified to argue about, but all paint allows the passage of water vapour, while hopefully resisting water droplets. Some figures were posted here a while back which suggested that surface coatings offer virtually no resistance to vapour. I wonder whether paint would peel off new lapboards as easily. I think wood just deteriorates with age and becomes porous to the point where it cannot support a coating.
"stuart noble" >without vapour barriers and or adequate ventilation moisture condenses as
Oil based paint on bedroom ceilings will certainly act as a vapour barrier. Not a full one, but will certainly help.
Very interesting stuff, but of course in teh UK we don't get that much ultra cold waeather, and teh cost benefit of such a system as described below is not as great, if indeed it exists at all.
I certainly agree that hermetic sealing with heat exchange makes sense if the temperature outside is going down to -25C or lower, but n ts contry I am not conviced that the capital cost of that plus such extremely high levels of inulation and sealing is justifed on either straight economic or enegy saving basis: It does take a lot of energy to make the materials of such a house.
I keep harking back to teh mediaeval castle, with a kitchen at the base running chimneys up gians flues through teh walls to living quarters above.
The ultimate eco house probably has huge thick walls of simply earth, and ventilation via long shafts that run next to flues so a natural heat exchange would occur.
Yes, but the whole point that you ALWAYS fail to realise is that cost benefit analyse comes up with different answers for different climates.
In the Mediterranean and indeed in most tropical places, its well known that insulation is pretty useless unless you also install air conditioning, and its better to rely simply on shade (overhanging eaves) and a lot of mass to average out diurnal temperature variations.
Mediterranean houses seem to have rooves of triple layers of tiles cemented together, and concrete without insulation at all is the preferred wall material - or simple blockwork. Timber house get insufferably hot.
Yet in scandinavia, timer with massive insulation is the simple cheap way to achieve warmth in winter.
One size fits all is your mentality John, and its an ideological disaster everywhere its been applied.
What codswallop!!! Look what they do in Florida.
On Tue, 24 Aug 2004 17:43:25 +0100, "stuart noble"
Hi,
The problem with damp painted wood is that when the sun hits it the water may not escape through the paint fast enough and it gets almost steamed off :)
No, it won't change if it's protected by a coating, unless it's rotting away.
cheers, Pete.
Correct ventilation cures that.
What tripe! Look at what Gorki Deveci has been doing in the UK.
That is because you are ancient.
You mean build timber frame houses with insulation, dry lining and loads of air con?
The air coming out of the lungs is at 37C, 100% humidity. (the air coming out of the mouth may be a hair under this) This works out at 40mmHg, or maybe 1/20th of the atmosphere coming out. At 15l/min, that's .8l/min of water vapour, or 384l/night. As water, that's about 200ml or so.
However, it's only reasonable to insulate to the appropriate level. Canada gets a mite chillier than the UK. Insulating over what you need doesn't gain you anything, it just means you have to do extra cooling.
What tripe!!!! Do some reading. Find out, don't make it up.
Yes.
... and repeat after me three times "We're not in Kansas any more, Toto"
Do you tango in ruby slippers?
.andy
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