Vacuum tube solar collectors.

[The Natural Philosopher]

No.

If my wife can sleep with two dogs on the bed, she can surely put up with me. ;-)

Just a wash of the most offensive parts. As we used to do in the 50's

[The Natural Philosopher]

The people that is addressed to are the ones who don't have anything worth listening to, anyway.

Once it was double glazing salesmen: now its ecobollocks/greenwash salesmen.

[David Hansen]

On Wed, 9 Jul 2008 02:55:02 -0700 (PDT) someone who may be Andy Dingley wrote this:-

They should be more reliable than one with the water flowing in the tube, due to there being no water joint between the tube and manifold to leak water. Also if a tube is broken that just reduces heat output, it does not cause the water to leak out and thus bring the system to a halt.

The insulation of the tube depends on the vacuum between the glass, so no difference to a similar tube with water in it. The insulation of the header should be slightly better as there is no real possibility of water leaking into the insulation.

shows the top of a tube, with the heat pipe pulled out. Normally the white plastic bit is "corking" the tube and just the heat bulb sticks out. The top of the glass goes a fair way into the insulation and the heat bulb goes into a rubber pocket in the manifold, with heat conducting paste between the two. The end result is well insulated and conducts heat well.

You may see the arrangement of one design of tube to manifold joint in the (Microshit Word) document at

in the section which starts with "Collector Dimensions", in particular the photograph on the right. This has one half of the insulation removed so one can see the manifold. In that picture the black rubber cup has been removed from the bottom manifold position and the tube only pushed part of the way in. The top manifold position has the rubber cup which is normally in place and which provides a good seal.

It is a well engineered arrangement.

[David Hansen]

On Thu, 10 Jul 2008 17:07:25 +0100 someone who may be The Natural Philosopher wrote this:-

Ah, a convincing argument.

Do keep it up.

[The Natural Philosopher]

The ecobollox/greenwash man himself!

Learnt to do basic sums yet?

[Pete C]

OK I'll rephrase; you won't get any help from *anyone* by telling people to fuckk off, will you?

cheers, Pete.

[David Hansen]

On Thu, 10 Jul 2008 17:54:28 +0100 someone who may be The Natural Philosopher wrote this:-

Excellent, proof by assertion. Do keep it up.

Nice try. However, it fails as usual. I learnt to basic sums a very long time ago and then progressed to more complicated ones.

Do keep trying though. It is mildly amusing.

[David Hansen]

On Thu, 10 Jul 2008 08:49:52 -0700 (PDT) someone who may be Pete C wrote this:-

Probably not. However, you are making an assumption there.

What is more revealing, I think, are the numerous gaping holes in the arguments put forward by the anti-greens. For example the largest manufacturers and uses of vacuum tubes for water heating are the Chinese.

[Andy Dingley]

Bloody hell, that's cheap!

[Guy Dawson]

Looking at the figures from my gas and electricity supplier (eon) in Jan and Feb of this year we averaged 90kwh per day on gas to heat the house and hot water. In June we used a little under 20kwh for hot water so I estimate we're using 70kwh per winter day on heating.

Guy

[The Natural Philosopher]

Dunno. Sometimes it works wonders with those who agree with the sentiments ;-)

[The Natural Philosopher]

So what happened? senile dementia? Or are you just lying again?

[David Hansen]

On Thu, 10 Jul 2008 10:48:35 -0700 (PDT) someone who may be Andy Dingley wrote this:-

But still a well thought out product. Despite the discrimination against DIY with regard to tax and grants it makes it well worth doing as a DIY project if one is able/willing to do so. If not there are installers.

The unlike some models the tubes don't limit themselves, but the control system will do that and proper system design to minimise the effects of overheating deals with the odd case of control failure.

[Andy Dingley]

One thing that annoys me about solar at the moment is the back-biting and in-fighting between products. I used to live in Northern Ireland, where Thermomax is all too often portrayed as "The good, solid, god- fearing local product", in opposition to all these nasty Chinese imports that are stealing our good ideas. Except that when you dig deeper, the real innovations in solar over the last 20 years have come _from_ China.

Thermomax are also less than helpful on information and even less forthcoming with pricing. I really do not appreciate an attitude of "Best talk to a proper grown-up installer", when the market is still in its infancy and the people most likely to really understand what's going on are bearded amateurs who turn out to be surprisingly well- equipped with workshops, thermodynamics or control theory knowledge and numerate Oxbridge degrees.

An area I just haven't looked into yet.

I'm looking at South Wales. If I _can_ cook a tube with the Sun, I'll have it framed.

[David Hansen]

On Fri, 11 Jul 2008 03:04:03 -0700 (PDT) someone who may be Andy Dingley wrote this:-

One of the more odd assumptions about the Chinese is that they are backward and that their only thoughts as far as energy is concerned are how many coal fired power stations they can build. The "whatever we do in the UK is pointless because the Chinese are building X coal fired power stations a day/week/month/year or whatever" one.

In fact the Chinese have developed a variety of renewable energy/energy saving schemes and have lots of them installed. As you say, they have done a lot in the solar field.

This does lead to the question of whether one should buy equipment from a repressive regime on the other side of the world and transport it here. I don't have a simplistic answer to that question.

I agree. I speak as someone with a little idea about thermodynamics and control theory, having studied both at university. However, I wouldn't be as disrespectful to installers, some are very knowledgeable. Navitron welcome all sorts of people, their web based forum is a good source of information and they will sell bits rather than trying to force people into one of their kits.

IIRC there is a solar cooking forum area on the Navitron forums.

[Andy Hall]

Do you sell double glazing as well?

[Andy Hall]

Well... that would be reasonable since they are among the fastest growing polluters. We ought to try to get something back for that.

[geoff]

In message , Andy Hall writes

I thought that we did - a lot of their pollution comes from producing exports for the "west"

[Andy Hall]

So should we then be paying more for what we buy, producing goods closer to home and under cleaner conditions?

Currently the West speaks out of both sides of its mouth on this issue.

[geoff]

not if you're purely a slave to market forces

what are these production facilities of which you speak

having ceased to be economically viable in the past few years, many of them have gone forever

what do you expect ?