Thanks for all the assistance have just caught up with this thread got a bit messy half way.
Things that we are going to be considering are:
Cellar, not for living. Superinsulation, Cat5 wiring
Just one Q's with superinsulation what kind of heating would you go for, were just a bit concerned that the house will be cold, (We tend to like the house warm)
"John Borrman" wrote | Just one Q's with superinsulation what kind of heating would you | go for, were just a bit concerned that the house will be cold,
In this month's Homebuilding and Renovating (or similar titled glossy) there's a Super E (?) airtight house built to canadian standards which uses ground source heat pump heating.
Owain
LOL!
Yeah - but Canadian electricity is cheap. I'd look at mains gas driven heat pumps as these are a lot cheaper to run, albeit more noisily.
In message , Frank Erskine writes
Can you laugh with a perforated tongue ?
Good opportunity to install a wall of solar flat plate space heating. Excellant payback. Alt.solar-thermal can help there.
NT
If it is genuinely superinsulated (walls to U value 0.1ish) and air tight, you will need a heat recovery ventilation unit. Uprate the ducting and have either an electric duct heater battery or a wet copper coil heated by a boiler which will also do the DHW. Forget underfloor heating as a superinsulated, or just well insulated, buildings don't require it. With electricity the capital cost is far lower for heating and DHW, than a gas boiler, and no annual boiler maintenance costs to offset the electricity costs. A boilers flue has to be taken through the roof in a solar house, so to prevent a large cold bridge via the flue through the wall.
Also install solar DHW panels on the roof and shower waste heat recovery.
Well insulated houses can have the room temperature lowered without any discomfort. Far less heat is being extracted from your body due to the high insulation.
I would consider superinsulation for one minute and then go for it. Get the basic shell right in insulation, thermal bridging and air tightness. All the rest after those three are aesthetic toys in comparison. You can fit a kitchen in later, but not change the insulation with major cost and disruption.
Join the Selfbuild list or group. They are much more clued up on this.
The message from "IMM" contains these words:
A scientific breakthrough?
To the accepted methods of heat transfer (conduction, convection and radiation) we will have to add another to account for the remote action of insulation. It will be only fair to call it the DIMM - distance-insulation-magical margin.
OTOH it is much easier just to accept conventional wisdom that dIMM will take a not entirely improbable notion, multiply its effect 100 fold and then come up with a completely wrong explanation which he will relentlessly promote in a vain attempt to wear down those who would challenge his absurd pretensions.
< snip drivel>
Babling misinformation.
Poor thing, everyone needs a hobby. Why not indulge hIMM ...
Mary
Am I being stupid but wtf was Roger going on about
You are not stupid at all. Roger is not quite with us in many ways. Ignore him.
Quite right Mary, Roger needs to do jigsaw puzzles 24/7.
No, but in fairness to IMM his first sentence is correct (provided the value of "lowered" is not excessive). The second sentence is also true, except that "far less" is something of an exaggeration.
Better insulation implies higher surface temperatures at the walls, which in turn, for any given air temperature, raises the mean radiant temperature and thus environmental temperature. Comfort is related to a combination of the air and radiant temperatures - not just the air temperature. It's a common experience that a room containing a source of radiant heat can feel quite cosy even though the air temperature is quite low.
It's called radiation :-)
The law of diminishing returns will have come into play on this particular effect though, well before you reach the 'superinsulation' category.
The message from Andy Wade contains these words:
I suspect the value of 'lowered' is very small indeed but the 2nd proposition is untrue and what's more doesn't follow from the first.
Comfort is the basis of the remark in the paragraph you snipped completely:- viz
"OTOH it is much easier just to accept conventional wisdom that dIMM will take a not entirely improbable notion, multiply its effect 100 fold and then come up with a completely wrong explanation which he will relentlessly promote in a vain attempt to wear down those who would challenge his absurd pretensions."
Feeling cold is by no means the same as losing heat. The better the insulation the smaller the temperature gradient across the room between heat source and cold sink and almost certainly in a well insulated house there will be none of those irritating little drafts that can con stationary bodies into thinking they are cold. However if the couch potato and the thermometer are in the same position then what dIMM alleges cannot take place. (In fact the reverse is true).
I'm not convinced that the marginally greater radiation from warmer walls would have any significant effect (see final para for the reverse effect) but to the extent that it does it makes diMMs conjecture even less tenable. The lower the air temperature (at which the body feels comfortable) the greater the temperature difference between it and the warm body and hence the greater the heat loss.
In which case it would not be another method.
Have you considered the fact that in a poorly insulated room there is much more radiant energy about that in a well insulated room?
A well insulated house will have fewer draughts (one would hope) so will feel more comfortable at lower temperatures. Not quite what IMM wrote, but some truth buried in there!
I'm having difficulty following your argument. I agree that the difference in surface temperature, at least in the steady state, is pretty small. If you compare two walls, one with a U-value of 0.4 W/(m^2.K) and the other with U = 2.2, assuming 21 deg. inside temp and
-3 outside, and using the usual value of 0.06 m^2.K/W for the resistance of the internal boundary layer, the difference in the inside surface temperature works out at only 2.6 K, according to my back-of-envelope calculation. However that 2.6 K difference is about 15% of the temperature difference between the couch-potato-body and the wall, so it will have a fairly significant effect on the heat flux. With intermittent heating in the poorly insulated place the difference will tend to be larger, due to the lag introduced by the thermal mass of (for example) solid brick walls.
By "warm body" here I presume you mean the heat source. In "the greater the temperature difference between it and the warm body" does "it" refer to the air mass or the (human) body? If the latter, it's at a fairly well-regulated 37 deg. or so and the air temperature doesn't affect the heat flow very much from the radiation point if view.
Well, no, my argument was constructed on the principle of there being less. Why is there more? It does depend on the heating source of course. A good blazing fire can make you feel quite warm in a very cold room, so in some cases you may be right, but so what? - it doesn't alter the radiation to the walls argument.
Good intelligent response by Andy.
< snip drivel by Roger >
A well insulated house can be like sieve. Air tightness and superinsulation don't always go together. When they do, the results are brilliant.
The message from "IMM" contains these words:
That's your argument demolished then Andy. Since dIMM agrees with you you must be wrong. :-)
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