Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Double versus triple glazing windows
Options
Comments
-
therightangle wrote: »Is it not similar to any other energy rating system? For instance A-rated houses can range from 0-75 kWh/sqm/yr
that's my point it confuses the average consumer
I agree that U-values are not the only consideration, but 'A rated' windows allow a variance from circa .8 to 1.5wm2k ???therightangle wrote: »I think it does, more so than the u-value alone does. If you want to comply with Part L alone, just look for good u-values. But if you want to get a good BER, get an A-rated window, as it incorporates u-value, solar transmittance, and air leakage, and all are essential for a good BER.
I don't dispute the benefits of 'A rated windows' from a BER rating perspective.. but the merits of this assessment process that is applied by the NSAI
yes there is an overlap..the OP wanted to know about Double v triple.. I was trying to explain (quiet badly) that double has its limits at circa 1.2wm2k and triple can continue down to below 0.8wm2/k. But I still fail to see your point. IMHO the WEP is just a half ass'd industry lead assessment method !!therightangle wrote: »Triple glazing does not start where double glazing ends, there is an overlap. Look at the DEAP (BER) Manual. Another reason to go by the window energy rating (WEP) and not get hung up on whether it is double or triple.
I disagree, by doing a spec the u-value, solar transmittance, and air leakage, the materials, the finishes, the ironmongery, the installation process, the overlap with wall insulation, the lifespan and required guarantees (but to name a few) can be written down and help to form a contract between the manufacturer/installer and customer. NSAI's scheme does not go far enough..therightangle wrote: »No need to do a spec - as long as the u-value gets you past Part L compliance for your glazed areas, just look for the window with the highest Rating Index when comparing prices, as per the link:
http://www.nsai.ie/Our-Services/Certification/Agrement-Certification/WEP-(Wind-Energy-Performance)-Scheme.aspx
absolutely i have been selective just as the NSAI have been 'selective' in their assessment methodology..therightangle wrote: »Selective reading and not the full picture....look at the line in the paragraph above:
"The WEP Certificate value combines the following characteristics to allow consumers to determine how well each window assembly will perform."
yes its an improvement but that's all...therightangle wrote: »True, but the Window Energy Performance (WEP) and the BFRC are big improvements than what we had - it gives the consumer a better handle on the true performance of the window and separates good products from mediocre products. It also saves everyone having to scramble for certification - if its on NSAI/WEP or BFRC then thats good enough.
IMHO the NSAI's scheme is flawed.. the 'A' rated scheme allows for vast differences in U-values and does not take a holistic approach methodology, for example the lack of embodied energy, lifespan or disposal considerations..0 -
-
-
Hope this discussion isnt going too far off topic, but Id like to address some points.sydthebeat wrote: »1. A window does not have to have a WEP certificate to access these values.
Actually, referring to the test certificates is a better means of determing these values than the WEP cert.
2. again, not correct. Any credible manufacturer will make test certs available to a discerning customer, and these should be used as part if the decision making process.
3. therigthangle, you appear to be implicitly stating that a window without a WEP is somehow substandard to a window that has a WEP. please clarify if that is your opinion?
4. i think bryan has dealt with this adequately above. I have been doing BER assessments for 4 years now and have never come across a situation where i have had to refer to a WEP cert. Actually, WEP seems to have a high majority of irish made windows listed, whereas when clients go looking for high spec windows, they tend to look towards teh continent. Thus, the test certificates tend to be the big equaliser when it comes to comparing windows, not a WEP.
5. if thats the view of a prospective customer, then they are significantly narrowing their market.
1. In my view, a WEP cert is easier to access than trying to find independently certified certificates for both solar transmittance and u-value for each window that you are trying to cost. Unless you have a very helpful salesman who actually gives you those up front and they are adequate for BER.
Syd, you would know that some certs are in the wrong language, incorrect testing standard, incorrect testing body, etc.etc. but the purchaser doesnt know this. The selfbuilder who buys the windows can be easily misled without a WEP cert.
2. I take it you are referring to the ideal world....
)
3. No
4. No one forces you to refer to it, but if its there and its easier....? Thats like saying you prefer to chase boiler certs instead of just looking up the HARP database. Imagine how many consumers would be getting ripped off if there was no HARP database for boilers? The WEP brings the same clarity of comparison between windows and makes the buying process easier for consumers, IMHO.
5. Possibly narrowing their market, but "narrowed" to over 60+ models of A & B rated windows and growing, all of whom are interested in supplying to Irish buyers as they have gone to the trouble of getting certified in Ireland.
Syd, Bryan, let me give you an example....and Id be surprised if you have not come across this already in your BER experience:
A cert from a large manufacturer down south is tested by an approved independent certifier for u-value and achieves 1.2 u-value. Job done you would think for the vast majority of consumers and many BER assessors.
But the cert fails to mention the solar transmittance standard. So now you can throw that u-value in the bin as regards BER, the consumer has wasted their money, the assessor runs the risk of getting penalty points via audit, and the house runs the risk of not complying with Part L Building Regulations.
If the window had been on the WEP list....no worries.0 -
-
Advertisement
-
-
-
-
-
-
Advertisement
-
-
-
-
-
-
-
-
This discussion has been closed.
Advertisement