condensing question

[Paul Barker]

Yes gassaver beats solar.

 

[Dan Robinson]

I have seen the Zenex unit running and it is actually very impressive. It's implementation leaves a bit to be desired, but then when you are directly interferring with the flue line of a boiler there is only so much you can do with the current attitude to things in the building industry.

The Dutch system of "classing" flue systems give much more flexibility and if we adopted that system (which I suspect is on the cards) such innovation would be much easier. It allows the boiler manufacturer to say - you can use (for example) flue product group A, E, and F with our boiler model X. How prevalent this is in other parts of Europe I can not say - I have only experience of the Dutch system.

As far as gas appliance efficiencies go, flue products are about the only avenue left open.

 

[htgeng]

The Dutch system of "classing" flue systems give much more flexibility and if we adopted that system (which I suspect is on the cards) such innovation would be much easier. It allows the boiler manufacturer to say - you can use (for example) flue product group A, E, and F with our boiler model X. How prevalent this is in other parts of Europe I can not say - I have only experience of the Dutch system.

I install Atag boilers and I have to say I haven't heard of this before. What does it mean in practical terms. I would have thought if you have 80mm flue it would work with any boiler which has the same diameter outlet.

 

[chrishutt]

A company called Zenex have a product called Gas Saver which sits on a boiler flue and harnesses more of the heat ... I fear innovative products like Gas Saver will be ignored.

I think it should be ignored. It's extremely expensive and of only limited value in recuperating heat losses. It cannot possibly be value for money.

 

[Dan Robinson]

I think it should be ignored. It's extremely expensive and of only limited value in recuperating heat losses. It cannot possibly be value for money.

It is as things currently stand, but as I mentioned earlier; that does not have to be the case - especially now that in-flue condensation is no longer an issue.


htgeng. Every boiler has differrnt internal resistances and that is what determines max flue length. We fit one boiler that can have over 100m of 80mm flue; yet another can only have 64m and another 60m. With a 5" flue the last two boilers have a maximum of 32m and 30m. using 50mm MuPVC the first and third boiler has 9m and 10m lengths.

Same flue products different boiler manufacturer.

Unless I am talking out of my hat in which case; in the morning I'll see things differently!? As I see it the UK manufacturer's treat most installers like idiots instead of giving a bit of creative room; although I do remember Ariston being fairly flexible at one point with thier fluing options - Italian though weren't they?

 

[simond]

Chris H

Gas Saver is expensive, but then so is solar. Solar is so expensive that it is dubious in most domestic situations that it will ever recoup the initial installation and capital cost.

When Gas Saver came out, I recall that they had some figures from the Gastec laboratory showing payback in about 6 years on a combi. Perhaps I am mistaken, please advise.

The Gas Saver also has the advantage of almost removing the plume, which would be useful in high density housing.

 

[chrishutt]

When Gas Saver came out, I recall that they had some figures from the Gastec laboratory showing payback in about 6 years on a combi. Perhaps I am mistaken, please advise.

We had a debate on this on the ARGI site when I looked into it. As far as I could see there was no published data that could be examined for credibility. They made various claims, as manufacturers do, but nothing that could be verified.

A Google search on Zenex Gas Saver will give some interesting information to note. The energy Savings trust were assessing this product back in Feb 2006 but appear to have decided not to include it in their list of energy saving products. Perhaps they know something?

It may or may not be that it's a better value investment than solar, but that doesn't make it a good investment. Insulation and draught-proofing are where we find real cost-effective benefits, but it's just not as sexy as big metal things with pipes.