OT:Windmills

[Roger Chapman]

Even in your world you need a model before you can apply your fudge. What makes you think there is a model?

[Roger Chapman]

That hardly needs a model. The interglacial will be coming to an end shortly unless global warming manages to delay it.

Forgotten why I asked? You need to go back thousands of years to find a warmer world than we have at present.

As I always try to tell the truth I would be very surprised indeed if you claimed you did.

[Steve Firth]

[snip]

58mm x 1800mm

25mm.

This is the black pipe with a blue stripe along it suitable for potable water. [snip]

I've been considering either a swimming pool or a large underground tank of water for use as an intermediate thermal store. I have a suitable

2000 litre tank on the farm at the moment.

[The Natural Philosopher]

build a triple glazed conservatory, and a ground source heat pump. Both far better solar collectors.

[The Natural Philosopher]

All my hot water needs in summer can be supplied by cupful of kerosene.

[nightjar]

In Antarctica, in particular, it is better than shrinking

Which I find a bit of an odd statement, given that we have been told that Arctic ice is thinning, based upon radar measurements.

...

Which could be due, at least in part, to hystersis.

....

It seems to be unusual enough for a number of observers to suggest it could be the prelude to a cooling cycle.

Colin Bignell

[Dave Liquorice]

I've told you a million times to stop exaggerating. B-)

300ml of kero only has enough energy to run a 3kW kettle for about an hour.

[dennis]

So the idea its caused by the ozone hole is just another guess portrayed as fact then. I suppose you will just start quoting it as fact just as you do with everything else you post in this thread.

[Roger Chapman]

snip

It is a theory based on the available evidence.

[Jules]

GSHP would be nice - I'm sort of waiting on that one for a few years until there are a few more documented 'homebrew' systems around, though (plus I want to monitor ground temps at different depths to work out how deep to put the loops). I expect I can do a lot of the work myself (loop installation in particular, which seems to be where a lot of the cost goes for a commercial install just because of the labour involved).

Conservatory's an interesting one; does that imply that heating water via a thin glass 'sandwich' is far quicker than doing so via opaque tubing? Maybe a glass front, 1/2" or so of water space, and a reflective backing... I might do some experimentation there sometime (I've got some

8'x5' glass sheets that I don't need, but I'm not sure what would work best as backing and which wouldn't either be toxic or disintegrate fairly quickly... but maybe toxicity doesn't matter if it's run through some form of heat exchanger)

cheers

Jules

[Jules]

Hmm, that's more than I expected - but that's just gut feeling rather than actual research on the matter :-)

Aha. I suppose I could use the irrigation stuff and run it via some form of exchanger - but even then I'm not sure of its longevity (plus I'd have to drain it down in the Winter). That irrigation stuff's only 1/2" dia but it is good for experimentation - it was less than $10 for 50'.

I meant to do some testing this Summer, filling some section with cold water and monitoring temperature rise, but never quite got the tuits together. Next year, hopefully!

Useful. I have space for such a thing here, but I don't have anything suitable handy. Plus the climate here is consistent temps in the 70s and

80s during Summer, but 30 below in the Winter, so anything with water in it needs to be laid pretty deep to avoid freezing (our well water comes in around 7' below ground level)

cheers

Jules

[Roger Chapman]

nightjar >> Some areas are melting, but others are freezing, with the overall effect

I am not sure about that. I presume the report is primarily about sea ice rather than glacial and the Antarctic has much less capacity for sea ice than the Arctic due to the large land mass currently stationed at the South Pole.

Only recently some brave chap has returned having conducted an on the ice assessment of Arctic sea ice thickness, apparently, to a much better standard than Sonar from a submarine. Perhaps that was ground radar of a type similar to that used by archaeologists.

Much of the Northern ice sheet is now only first year ice which melts in the Summer without the chance to thicken in subsequent winters.

Very probably. Oceans substantially lag atmosphere so the continued emission of oceanic CO2 with provide a forcing agent for many years to come (always assuming CO2 is a significant greenhouse gas :-)).

link please.

>

[The Natural Philosopher]

Yes, that's what my hot water needs are per diem.

about 40 minutes of 3KW immersion heats a 250L tank, enough for all washing needs for two people - more in fact if large baths and showers do not feature.

Let's see. 250Litres of water at say - 10C heated to 60C is 12.5M calories. About 14KWh for a completely cold tank to 60C.. Now we very very seldom use all of that in a day.. Only if my wife decides she is filthy from gardening and fancies a 30 minutes full blast shower, AND I take a filled to the brim hot bath at the same time, neither of which are common events. In reality its more like a 3 minutes shower and a bit of hand washing now and again.

I know, because in summer the ONLY thing our boiler does is heat water. It is NEVER on for more than 20 minutes, and its a 12KW output boiler.

In mid-winter, to heat the house, its seldom OFF.

[Steve Firth]

So where did you get the 100% efficient generator from, and are they a reasonable price?

PS. Stinky stinky you are stinky, poooo!

[The Natural Philosopher]

Its well documented. About a meter nets you nearly all the gains you are ever going to get. More than that is a waste.

? I expect I can do a lot of the work myself (loop

Yup. Digger in, and then lay the pipe. BIG loops at least a couple of meters apart, and in the wettest soil you can find. Clay good. sand bad.

No, I mean in winter you will get more solar gain from a south facing triple glazed window than from a solar panel on the roof. It wont heat water, but who cares? heating water is the least of your worries, it WILL heat the house. FAR more cost effective.

Don't worry about water heating, that's my real message. Unless you live in an urban environment in a very highly insulated house, of small dimensions and are obsessively clean, hot water is the smallest energy use you are likely to have. You probably use more making coffee and cooking.

And lighting, in winter.

You certainly will use far far more on space heating, if the house is of sensible dimensions, unless its designed to a very high standard.

even in my 'meets 2000 specs' house, the dominant heatloss is ventilation. THAT I AM REQUIRED TO HAVE. without going to heat recovery ventilation, adding much more insulation would not achieve a great deal.

That's fairly calculable in terms of air charges per hour, specific heat of air, internal and external temperatures and and volume of building.

The physics of heating show that whilst soloar, and heatpumps are very good at raising largish masses a little, they are not very good at raising smaller masses a lot. Hot water nearly always wont reach 60C or whatever the temp needed to guarantee no bacteria, on solar or heatpump alone.

As data point, a sunny winter day into my southwest facing heavily glazed room results in about 3-5C rise in it.

As another one, my 12Kw oil boiler, given the right UFH and a modded upstairs heating circuit, could be replaced by a 3-5Kw heatpump and still do the job.

[The Natural Philosopher]

I calculated that a cubic meter of water in an insulated tank here could supply my heating needs for 3 days if heated to boiling point, and with a lower cutoff of 60C..very simple heatbank.

spherical is best (greatest volume to surface area) but a cube aint bad.

[Jules]

Well, it must vary be region...

Hmm, having just dug some post holes we seem to be sandy stuff down to

30", but I'm not sure what's down deeper than that.

Aha - gotcha.

Ha. 1940's wood-framed single-glazed French windows which leak air like a leaky thing ;-) The loft insulation's good, but no idea what the walls are like; it'll all be 2x4 dimensioned lumber framing, so no more than

3.5" of insulation, and who knows what crap they threw in there when the place was built. Couple that with Winter temps of 20 or 30 below...

Having said all that, the bill wasn't too bad last cold season. Maybe $450 for the 'leccy heaters and a similar amount for the propane tank. Spread across the year it's not bad considering the harsh Winters here and having a daughty old house.

Yes, I wouldn't expect it to do the whole lot. But cold water from the well seems to be consistently around 50 degrees F through the year, so anything that can raise it a bit seems to make sense *providing there's no big financial outlay to do it* (which is where so many of these schemes seem to be crap, because the commercial outfits charge through the nose for supply and install)

It certainly made a noticable difference here last Winter; the south-facing glass would get considerably warmer than the rooms even when there was a few feet of snow on the ground. (heh, something to monitor glass temp and just say "hey, go open the darn curtains now" would be useful ;)

cheers

Jules

[The Natural Philosopher]

well in terms of heating, even an oil boiler does 75%-80%.

No, I just dont waste money on hygiene I dont need..

You may be obsessive compulsively clean: I see no need to use 100 liters of hot water a day to wash of less than a gram of dirt and sweat.

But letst take solar heating. 10 sqaure meters of panels can deliver an average of 13Kwh a day.

Thatst enough to heat my tank. Its roughly equivalent to 1.3 litres of oil a day.

So lets say 500 liters a year. Around 250 quid. at 50p a liter Now how much does it cost to install and maintain 10 square meters of solar water heating?

the price I saw was £2500 for just 3 square meters. So lets say £7500.

About 3% ROI. I can get more by leaving it on deposit in the crappiest bank. Now add a likely maintenance cost of whatever, and a probably sub

25 year lifespan, and the thing is hopelessly and completely uneconomic, and furthermore, since the cost of it by and large reflects the energy in to make it, its also worse than carbon neutral Its carbon POSITIVE.

I.e. I use less carbon by burning the oil, than buying the solar heating system.

Now that's not to say if you cobble something together from scrap, its not a better use of that scrap and probably YOUR time,than simply doing something worthwhile, but there you go. I live in the real world.

[The Natural Philosopher]

No. what you are looking for is the level at which the annual temperature variation is relatively small.

In general summer to winter variation is massive for the first few inches, and then it simply tails away. a few tens of feet there is NO variation at all. If you are in siberia its permafrost down to many feet, before geothermal heat takes over, for example.

Oh. You may need a lot more pipe then. up to 2.5 times more.

Ok, I am not much different, except my walls are stuffed full of rockwool. Should have used celotex really.

Plenty of scandinavian houses use the name.. the secret is to rip out the cladding and insulate up 0oh and 2x4 is not enough to make a house out of. Id suspect at least 6x4's for main framing.

Draught proof and use thick curtianns or DG or TG for windows.

Try nearerd £2200 for electricity and oil here..

exacterly.

At the least, you could e.g. take the well water through ventilation shaft heat exchangers to use the internal heat you need..;like biuld a ccvhimeny and lowe level iar input and let teh hot ior out via a coipper spiral pipe in teh chimenty sortr of thing.

yup.

[Steve Firth]

The 25mm pipe was £100 for 100 metres, so about £15 for 50ft. I'd say that you need much more than 50ft based on my experience. The use was an accident - I temporarily laid an averground length of pipe to the barn in the spring then as we got into summer my wife started to complain about getting scalded by the cold water feed. We buried the pipe in a trench to avoid that, and used the spare pipe we had around (about 100 metres) to use as the hot water supply. It works even as late in the year as November, but it goes very cold quickly at night.