Siting of panels for solar water heating

On Sat, 18 Nov 2006 17:28:06 -0500, Joe Fischer wrote:

But if the A-380 is ever used by airlines, fuel use all over the world will go up.

You really do have shit for brains don't you? Maybe you are a bitter Boeing employee with an axe to grind.
555 persons moved 15000km with 300000 litres of fuel which per person roughly equals 3.6 litres per 100m, or in dipshit Yank terms 65mpg (US), (78.5mpg in the civilised world)
Come back to me and claim your prize of a shiny gold nugget when the average fuel economy of ALL USA passenger vehicles i.e including SUV's gets to 50% of that level. Just to give you lard assed yanks a fair crack of the whip this offer holds good for the next 500 years. I doubt you'll qualify to collect.
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On Sun, 19 Nov 2006 10:24:50 -0000, "Mary Fisher" wrote:

"Dave Liquorice" wrote in message On Sat, 18 Nov 2006 16:25:16 -0500, Joe Fischer wrote:
Maybe you don't have hail storms, tornados, hurricanes or earthquakes?
We have all of those apart from hurricanes,
We've had the odd one .... and several tail ends.

We might have had hurricane force winds on the Beaufort scale, but technically, in recent recorded history, we've had no hurricanes in the UK and that includes both the 1987 and 1990 "windy events"
--

In message , Peter Parry writes

On Sun, 19 Nov 2006 17:44:52 +0000, John Beardmore wookie@wookie.demon.co.uk> wrote:
One development in the UK is state intervention in the market to accredit installers and equipment.
A great pity the accreditation didn't involve actual testing of devices to prove they worked and that their performance was at least close to the sellers invariably vastly overstated claims.

Too bad you don't know what on earth you are talking about then. That's precisely what the accreditation of equipment does cover !!

Neither of the only two "accredited" toy windmills in the UK has had to pass any performance test at all and the makers hopelessly over inflated performance claims for them now come appear to come with government approval (which of course may well be a poisoned chalice in its own right).

OK, if you want to change the subject to wind things are a little different, but my comment above was about solar - like pretty much the rest of the thread.
Moving on to something completely different - I've already pointed out the problems with urban wind, cited web sites investigating the extent of the problem and offered a report about it if anybody is interested, but I don't see it as a problem with the turbines per se, so much as with the fairly dumb desire to market them for use on houses.
As far as I recall the Windsave machine quotes a rated power at a given wind speed - and there is nothing wrong that per se, it probably meets that spec, though a proper power curve would be nice.
The real problem is that the quoted wind speed is 12 m/s, and there is a cube law between wind speed and the energy that can be extracted. This is something the public - and indeed many of the sales people at B&Q level may not appreciate.
I have also pointed out some problems with the wind hardware accreditation process, but that was in the closing days of Clear Skies, and while they agreed with me, they seemed content to leave it to the Low Carbon Buildings Program to sort out.
Cheers, J/. -- John Beardmore

In message , Joe Fischer writes

On 19 Nov 2006 meow2222@care2.com wrote:
I wanted to buy small heat pumps, and saw they are available in the UK, but couldn't find any here,

Interesting ! When I was looking for small heat pumps I got the impression that they were available in the US, but not in the UK.
What did you find in the UK ?

In the summer, I hear a lot of A/Cs running, I can't imagine what it would be like if everybody had heat pumps running in winter. But there are lots of days here when a heat pump is worthless, at about 10 or 15 degrees F, they don't do much.

Which is why water source and ground source are generally more popular than air source for domestic space heating here.

I would really like to build a combination ICE running on ethanol, driving a generator and a heat pump, and using the waste heat to run a still, and use the waste heat from the still to help heat the house. But I have too many projects now.

:) Know the feeling !
Cheers, J/. -- John Beardmore

In message , Mary Fisher writes

Given that the only realistic saving is in hot water (an optimistic 70%), not house heating (when it's REALLY required)
I wonder what is thought of as REALLY required.
Our thermostat is set at 10C - that is, the thermostat is wound to its lowest setting. When it comes on in the night, as it did last night when we had a frost, it's too hot for us.

Turn down the boiler then ?

or cooking
Cooking with fuel economy demands intelligence and planning. Strangely enough I was taught that in school in the very early 1950s. It works.

:) Excellent !
Cheers, J/. -- John Beardmore

On Sun, 19 Nov 2006 13:49:50 +0000, John Beardmore wrote:

In message x Joe Fischer joe@westpointracing.com> writes On Sat, 18 Nov 2006 raden wrote: if the A-380 is ever used by airlines, fuel use all over the world will go up.
Fuel per passenger will come down.

I read about it every week, and even with new engine technology, I don't see how the cost of 555 seats warrants the cost of the extra 400,000 pounds.
But trials are going on now.

Are you sure this isn't just a weak attempt at a protectionist argument ?

Not any more, I had been concerned though, not as much for the commercial activity as for keeping critical production lines and military equipment from being at risk.

How did mankind survive 200 years ago ?
Depends on where, eskimos wore skins, and ate lots of blubber for energy. Rural Eastern Europe lived in shacks with dirt floors, and on real cold nights invited the cattle and pigs in, and cuddled with them.
Hmmm... My family were never keen on getting a sheep...

A couple of months ago I met a man raised in southeastern rural Europe, and what he described for the late 1930s was not pretty.

I guess maybe in the UK, coal was being burned for heat.
Never very efficiently.

In the 1930s, I lived without electricity, but the coal mine was across the street, and the pot belly stove was often red hot, my parents should have given me instructions on how to get the most heat with the least coal.

or giving up income.
Well that's the rub - when you're living beyond your (ecological) means, you have to cut back
Unless Saudia Arabia keeps selling oil.
For how long ?

I think they are planning for 200 or 300 years at least.

similarly with energy consumption
I am all for planting every square acre in sugar cane, potatoes, beets, water melon, and everything that can be used to make ethanol. But that may not work in every country.
What proportion of US energy demand would that meet ?

The US is the second or third largest oil producing country, and burns almost no oil in power plants, so with conservation, the trend toward flex fuel and hybrid electric, and other transport energy efforts, I think ethanol could fill the gap if imported oil was cut off.
Incidentally, I think there is some distortion in US oil imports, I think a lot of oil is imported to the east coast, and Alaskan oil is sold to Japan to save them shipping costs.

... which needs a cunning plan, not people turning off their TVs and disconnecting phone power supplies
There is time, at least in the US, but I see Europe in a critical situation, with an urgent need to do something to assure that people don't freeze.
So why is the US situation so much better ?

The US produces or gets about 75 percent of the energy in North America, I am not aware of any country in Europe that has much fossil fuel that is available without ships or pipelines free of any political issues.

Even if there is a crisis, action will be fast, and a solution will be worked out (unless you are talking about sea level rise, which is going to happen anyway). My problems are just keeping warm in 2 rooms and bath
Well - solar DHW meets out bathing needs directly for about 6 months of the year. I commend it to you ! Cheers, J/.

Now you want me to start taking baths?
Joe Fischer

Joe Fischer wrote:

Roofs and flammability are a real issue here, with a lot of house fires and terraces being very popular. If we had cedar roofs there would be many more deaths - we learnt that the hard way in 1666. My, you have a long memory. :-)

It's called history :-)
Local people here still commemorate the victory by William Wallace and the Scots over the English at the Battle of Stirling Bridge in 1297.
Owain

On Sun, 19 Nov 2006 19:46:16 GMT someone who may be raden wrote this:-

Today, with the outside temperature at 6C (and overcast sky) we had water at 25C. That's not hot enough for Spouse's washing up or my baths but it's fine for hand washing and it means that the boiler won't need to be on as long to raise the water temperature to his acceptable level.
So, considering it's not really cold and your system's struggling

Solar water heating works on the sun, not the external temperature. The two do have some relationship, but the temperature from a solar system essentially depends on the length and intensity of the sunlight, the external temperature is largely irrelevant (except for frost protection in some systems).

not really very good then

Look at the subject and note that the manufacturers say that solar water heating will provide nearly all the hot water in the summer, assuming a properly sized system, but need some boosting in autumn, winter and spring, depending on the amount of sunlight. The hot water requirement does not change much with the seasons.
-- David Hansen, Edinburgh I will *always* explain revoked encryption keys, unless RIP prevents me http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

In message , meow2222@care2.com writes

John Beardmore wrote: In message , meow2222@care2.com writes John Beardmore wrote: In message , SJC writes
Solar thermal panels for space heating is one of the ways we can save lots of fossil fuels in the future.
I really doubt it !
Whys that?
Because I strongly suspect that there will be cheaper ways to achieve the same thing,
I'm all ears as to what those are. I've not yet found anything cheaper or with better payback than solar flat plate speace heating.

Well, the first problem would be getting planning consent to build one in the UK, but hands on experience of solar in dull winder weather just suggests that the watts aren't there !
I know of one or two people that get a good solar contribution, but they've used heat stores and huge collectors, had big capital investment, and still have to burn some other fuel.
I suspect that a COP5 or better ground source heat pump in a super insulated building with good PASSIVE solar characteristics would be a better deal, simpler and with less kit !

(with one possible exception that I dont like)

Do tell ?

because the UK doesn't have that many cold but bright days,
No need, we have enough insolation to make it work and pay its way.

I'm not convinced that we do in winter. I'd like to see your calculations on this if you've got any ?

Space heating performs significantly differently to the more well known dhw because the output temp is much lower, and much more efficient mesh absorber panels can be used.

And these are more efficient in exactly what sense ?

because the sun doesn't shine when we need space heating,
the sun shines every day, and there is a simple way to use it to provide evening heat.

Yes - but many of the work best in orbit.

because passive solar design is more cost effective.
Unfortunately that one is too vague to know what you mean

Well go away and look it up then !

http://www.builditsolar.com/ & http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm
Yes - and there has been some good work done at one of the Glasgow universities, and there is a Nu Aire system on sale in the UK that we have looked at installing for somebody, and the Carbon Trust have waxed a bit lyrical in some of their training about merging all sorts of streams of low grade heat to heat space, but all of these things seem to require a lot of capital cost and super insulated buildings to be viable,
maybe, but none of that is applicable to the solar space heating I'm referring to.

No - but they are all worth looking at.

and they also require buildings to use, in some cases, whole walls as solar collectors which again rather begs the question, would passive solar be cheaper ?
would what passive solar design be cheaper than what?

The sorts of buildings that seem to be shown on the web sites you keep pointing at.

Cheaper to install, run, or what?

Well - none of them should cost much to run if the sun shines should they ?

It also raises planning issues, which knowing the UK, may take decades to resolve.
Perhaps in some circumstances, but not across the board.

:) Build one then !!
Cheers, J/. -- John Beardmore

In message , meow2222@care2.com writes

John Beardmore wrote: In message , meow2222@care2.com writes
A decently designed solar space heating system would not be using water in the first place. Picking hydronic for space heating is pretty much a design death blow.
Secondly, an entirely different method would be used to maintain temp after dark.
I suspect the notion was that the water would be a heat store.
Thats a dead duck way to design solar space heating, so no.
There is a comfort zone, not just one fixed temp at which people are cosy. Heat to as high in that zone as solar power provides, and you have n hours after sundown of sufficient warmth. N depends on design details.
If you go down the high thermal capacity route.
Brick/block houses typically have enough, and we've got lots of those here.

We've got lots of water here, so what specifically is the problem ?
Cheers, J/. -- John Beardmore

In message , meow2222@care2.com writes

John Beardmore wrote: In message , meow2222@care2.com writes John Beardmore wrote:
I suppose thats true of professional installs on rooftops, I'm thinking more of diy installs, where the cost for a decent area of tubes is way above that of flat panels,
But that's my whole point. At least in the UK, the prices are now pretty similar.
Youre talking navitron? When I last looked their cost per sqm was an order of magnitude above flat panels.

So are you looking at home made panels ? How many UK householders want to make their own ?
And no - not only Navitron. I was comparing Zen flat plat (or Filsol for that matter, or Imagination) with Focus and Apricus.
As a fraction of an installed system price, the difference is pretty small.

Flat panels can give much better performance at ground level or on a flat roof, as 1 or 2 reflectors are easily added to give anything from 1-2 suns.
Not sure why the same can't be true of ET systems ?
Tubes are concentrating collectors,

Well some have mirrors behind them, but many don't. As a generalisation that doesn't seem too accurate.

Equipment on a flat roof ditto, mounting the panel either at an angle from roof to wall or else flat on the wall, reflector below.
I guess the bug bear with that is getting end users to keep the reflectors clean, especially if they are flat.
Why would you need users to clean panels mounted flat against the wall but not ones on a rooftop?

The glass is frequently self cleaning, but above all, is unlikely to tarnish. When inclined, leaves etc are also inclined to fall off ! My point was that you might need to "keep the reflectors clean", especially if they were horizontal.
Cheers, J/. -- John Beardmore

In message , Joe Fischer writes

On Sun, 19 Nov 2006 13:49:50 +0000, John Beardmore wookie@wookie.demon.co.uk> wrote:
Unless Saudia Arabia keeps selling oil.
For how long ?
I think they are planning for 200 or 300 years at least.

Seems implausible.

similarly with energy consumption
I am all for planting every square acre in sugar cane, potatoes, beets, water melon, and everything that can be used to make ethanol. But that may not work in every country.
What proportion of US energy demand would that meet ?
The US is the second or third largest oil producing country, and burns almost no oil in power plants, so with conservation, the trend toward flex fuel and hybrid electric, and other transport energy efforts, I think ethanol could fill the gap if imported oil was cut off.

My gut feeling is that you are wrong, but the US does have a much lower population density than the UK.
Anybody done the sums ?

... which needs a cunning plan, not people turning off their TVs and disconnecting phone power supplies
There is time, at least in the US, but I see Europe in a critical situation, with an urgent need to do something to assure that people don't freeze.
So why is the US situation so much better ?
The US produces or gets about 75 percent of the energy in North America, I am not aware of any country in Europe that has much fossil fuel that is available without ships or pipelines free of any political issues.

Well - the UK did with the North Sea, but reserves are declining here as in the US.

Even if there is a crisis, action will be fast, and a solution will be worked out (unless you are talking about sea level rise, which is going to happen anyway). My problems are just keeping warm in 2 rooms and bath
Well - solar DHW meets out bathing needs directly for about 6 months of the year. I commend it to you ! Cheers, J/.
Now you want me to start taking baths?

Any sort of bathing will do ! As in "the act of washing yourself (or another person)".
Cheers, J/. -- John Beardmore

In message , raden writes

In message , Mary Fisher writes
Today, with the outside temperature at 6C (and overcast sky) we had water at 25C. That's not hot enough for Spouse's washing up or my baths but it's fine for hand washing and it means that the boiler won't need to be on as long to raise the water temperature to his acceptable level.
So, considering it's not really cold and your system's struggling
not really very good then

Considering it's one of the three months with the shortest day lengths and the amount of fossil fuel required for DHW is still being reduced, I'd say it was doing OK.
Cheers, J/. -- John Beardmore

In message , David Hansen writes

On Sun, 19 Nov 2006 19:46:16 GMT someone who may be raden raden@kateda.org> wrote this:-
Today, with the outside temperature at 6C (and overcast sky) we had water at 25C. That's not hot enough for Spouse's washing up or my baths but it's fine for hand washing and it means that the boiler won't need to be on as long to raise the water temperature to his acceptable level.
So, considering it's not really cold and your system's struggling
Solar water heating works on the sun, not the external temperature. The two do have some relationship, but the temperature from a solar system essentially depends on the length and intensity of the sunlight, the external temperature is largely irrelevant (except for frost protection in some systems).

Heat losses from the collector to the air largely account for the performance difference between flat plate and evacuated tube systems, so air temperature does matter.

not really very good then
Look at the subject and note that the manufacturers say that solar water heating will provide nearly all the hot water in the summer, assuming a properly sized system, but need some boosting in autumn, winter and spring, depending on the amount of sunlight. The hot water requirement does not change much with the seasons.

I suspect we shower more in summer to avoid smelling bad !
Cheers, J/. -- John Beardmore

In message , meow2222@care2.com writes

John Beardmore wrote: In message , cynic writes
I was dubious about the effectiveness of having the panel vertical so I have used 4 "L" brackets to mount it to the wall. If I find it lacks performance when the spring comes round I can simply extend the bottom brackets with mild steel bar.
You should certainly be able to boost it some.
With vac tubes it makes no difference whether theyr flat to the wall or not, as long as the tubes run horizontally.

A requirement which eliminates all the cheap robust ones with heat pipes.
The ones I know of that can have the tubes running horizontally have thermally vulnerable glass metal seal. Not my preferred choices.

One simply rotates the tube to face the incoming sun angle,

The ones I know of that can have the tubes running horizontally also have them brazed into the manifold.
What makes do you have in mind ?
Cheers, J/. -- John Beardmore