Guest post by Kevin Ahern
In my recent quest to understand the BFRC rating scheme, I seem to have misunderstood a lot of what the scheme is all about so I thought I would try to simplify my current thoughts in the topic.
The BFRC claim that A rated windows are net heat providers of your home. Ref. Giles Willson (at Glassex), Maurice Levitt (consultant and physicist), various correspondence, Graham Hinett (Fensa Times Dec 09) et al, and I am sure, many others, on numerous occasions, yet the BFRC guidance notes explain that the scheme is purely a comparison for windows and NOT an absolute performance measurement.
You see my confusion?
The document that explains the calculation of the formula (that has been peer, industry and academia reviewed) suggests that the sun provides more power in Aberdeen than it does in Plymouth. You see my confusion?
The same document goes into great detail about a Dutch reference house and quotes a number of British and European standards (and uses them negligibly) but does not state the reference source of the solar data that it uses. Calculations from the ASHRAE standards in the US suggest UK solar flux of up to 275 KWhrs/sq mtr (South facing) and 15Kwhrs /sq mtr (North), yet the BFRC manages to arrive at an average of 218.6 Kwhrs in their formula.
You see my confusion?
The scheme has been proposed as the only method of compliance to the 2010 part L regs, yet its administrators do not appear to grasp the issue of whether the WER is an accurate energy assessment or a marketing window comparison tool.
You see my confusion?
We are now being asked to pay lots of money to the BFRC for the privilege of having our products and businesses assessed to this compliance criteria in return for a colourful piece of paper, in which the resultant rating is neither a comparison or a net heat balance figure, or both.
You see my confusion?
Those amongst us who are actively selling A Rated windows to the public as net heaters of their property, could well be actually mis-selling and telling our customers lies (if the BFRC guidance notes 2007 are still valid). Could the customer sue you if your salesmen sold your windows as providing more heat than they lost?
You see my confusion?
Now the easy bit, this scheme has been purportedly government supported and designed to help the general public better understand the products we are selling them, ironically, along the way the BFRC appear to have forgotten the fundamentals of what their rating scheme is!
On the positive side, at least the scheme has the potential to be the only tool for the government to police our domestic replacement window industry, and a further benefit, by a strange coincidence (with the amount of solar gain claimed in the formula), it would also seem to offer an extended shelf life to some of the older generation Low E glasses, that, while not offering the best U values, let just enough more sun in to balance that problem out!
You see my confusion?
I have attempted to address some of these issues with the BFRC, but unfortunately, they give the impression that they are the scientists and therefore know best. The technical responses would appear to be based on the smoke and mirrors approach and actual answers very difficult to get to.
To summarise, I think the scheme has fallen between 2 camps, energy rating and window comparison, but wants to be seen as all things to all people. The problem lies in the application, accuracy and authenticity of the solar data , which for the purpose of windows in this heating dominant climate, is of limited value and should be thus be ignored anyway. The only data on the certificates, should be the window characteristics, (U and G values), and if the government wants to reduce fuel consumption it should insulate and use U values.
Any winter solar benefit (or summer overheating cost) is so dependant on specific site installation criteria (window size, orientation, trees, neighbouring houses and any other shading) that it has little or no place in a national window rating scheme for the installation of product into existing housing stock.
Ask yourself a question. Low iron glass, why ? Is this marvelous UV transparent product such a benefit to our society that we have long neglected it at our cost? Or is it just another gimmick to scrape a few more theoretical numbers on to our colourful pieces of paper?
Are we as an industry doing our bit to help James Strawbridge save the planet? Are we as an industry helping the government with the building regs 2010 Part L implementation?
Or, as some may argue, is the window industry taking the Mick out of Mr Strawbridge, the building regs, you and me, and worst of all, the consumer?
You see my confusion?
Kevin Ahern
Tags: A Rated Windows, BFRC, BFRC Rating Scheme, eco windows, energy efficient windows, G Value Windows, James Strawbridge, Kevin Ahern, Low Iron Glass, window energy ratings, Window U Values
RCG
Good points, well presented! As a wholesaler supplying the trade with a choice of window & door systems I have been watching with interest the whole WER situation over the last year in the hope that it would at some stage become clear so that I could align our product offerings accordingly. True, I am a simple Yorkshireman and 12 months on I am more confused than ever but would wage so is the majority of our industry!
In my frustration 6 months ago I thought b******s to this so now we supply as standard a soft coat, argon filled unit with a U value of 1.2 compared to a hard coat unit offering a U value of 1.7. I can get across the 30% better insulation and thats great. Although all our units have warm edge spacer bar I don’t mention it as this doesn’t effect the U value of the unit and if I do mention warm edge and I explain how fantastic it is but then have to explain that it doesn’t affect the U value of the unit everyone gets confused and credibilty, pardon the pun, goes out of the window!
Until there is clarity and more substance to WER’s, my view is that consumers will be more interested in saving heat going out because that’s what they are directly paying for. Yes, I know I’ve made a technically incorrect over simplified explanation by sticking just to the U value’s of the units, and its not representative of the whole window, but at least I can understand it and explain it – not something I can do with WER’s!
This is way too heavy for the 15th of December!
Well written Kevin – you clearly know your stuff!
As a specialist manufacturer of patio doors, which are not yet part of the WER scheme, I am grateful to be a late comer to this minefield. Even though patio doors are likely to score very well (being mostly glass) – U values are just so much simpler that I fail to see why the industry has been forced down such a complicated path.
In my ignorance I had thought that the BFRC was a government institution, owned by the government and not the GGF; more fool me! Perhaps I am technically wrong on this point – I’d be glad of a correction.
Following a long meeting with our glass supplier (we make vertical sliding windows too) I discovered how polictical the whole situation is and arrived at the following questions:
1. Krypton takes more energy to take out of the atmosphere than it will ever save by being part of a window – why is krypton used anywhere?
2. So confused is the issue that there are now two types of mass produced energy saving glass; one that gives the better U value and the other scores better on WER’s – what is the real point in that?
3. There are hundreds of thousands of units out there that have lost all the argon filling within only days / weeks of being made – I could get myself in trouble here so I’ll leave that point there – but we all know it happens with one particular very well sold system .. don’t we?
4. If the government is using WER’s to calculate any of the UK’s carbon reduction claims and if the same “type” of calculations are used in other industries across the economy, are we all chasing rainbows?
5. Are the Maldives still there – I fancy a holiday?
Ian
Thanks Ian
I have put quite a bit of time in on this as I am not one to stir for the sake of stirring , I have got some detailed research to back it up, but if it helps.
The BFRC is a wholly owned subsidiary of the GGF.
I have no real knowledge of krypton but I have no reason to disbelieve your observation.
I have my own theory about why the U value issue has become confused. I can’t prove that one but have strong suspicions. Can you thinK of any glass producer (that is in a UK trade federation) that produces an older Koated glass that may be mightily pleased that their Komparitevely high U values sKrape into the proposed tightened Part L regs on a solar gain Klaim ? Excuse the spelling !!
The Building regulations advisory committee have not actually investigated or technically questioned the WER scheme , they have taken the word of the BFRC that it is accurate, with peer, industry and academia approval . Apparently 1400 certificate sales illustrates industry acceptance! While the BRAC are not window people I am a little surprised that they have not independently scrutinised a scheme that carries such a responsibility in their legal documents.
I have heard stories about the disappearance of argon from units, but would love to see names named and test reports shown , we cannot continue to let fudged figures and claims be a staple part of the industry.
I believe appliance type rating systems actually specify the test conditions and performance tests used ie a particular wash cycle , or drying cycle with load criteria etc
The WER scheme does no such thing, it does not even work out which way a window is facing , average sunshine NSEand West , ridiculous !!!
I believe the Maldives are still there, but take your wellies with you ! but if we are still selling old low ‘E’ you may need your waders
…………….
With a life jacket and a boat .
Kev
I agree the new rules are complicated and there is potential for smoke and mirrors. It is also very difficult to advise your customers on the benefits to energy ratings when it is diffuclt to explain yourself. There are alternatives though!! the BFRC rated system does certainly work but can be unfathomable..at http://www.Synseal.co.uk we launched thermal inserts made from 100% recycled content. These are simple to understand ie they are recycled 100% pvc-u that is inserted into existing profile and does the following
1) its 100% recyclable
2) it increases thermal efficiency by breaking up air in the profile
3) they slot into any existing profile and can not only increase thermal efficiency but also the strength replaces steel up to spans of 3m
A new product for us but also a way to cut through the difficulties of understanding BFRC
see the below link for more info on thermal inserts and how they work in BFRC
http://www.lo-wercostwindows.co.uk/Thermal_Inserts_And_Thermal_Chambered_Frames.pdf
Cheers
Andy