Anglian Rated B Windows vs Local Firm Rated A

jchannon

Does that seem a good price?

cornerstone13

We've just been through a similar process and we've ended up paying £7000 for 15 windows and a back door. We went to four local companies (three of whom we discovered use exactly the same windows) and Anglian. The quotes came in at £10,600 (local, wouldn't budge), £8500 (Anglian), £7,700 (local, reduced to £7000), £7200 (local, reduced to £6400) and the lowest was £6400.

We went for the middle one as they have a good reputation locally and we felt "comfortable" with them - time will tell. All the locals offered A rated 28mm windows; Anglian were B rated 24mm.

jchannon

I'm wondering if I get A whether I would benefit from them because if I dont get sun then the A rated wouldnt perform as well and may only perform as good as the B.

What I also dont understand is that the Energy Index on the rating say that A rated gains 2 kWh/m2/per year whereas B rated loses 6. I thought the whole point of double glazing was that it wasnt supposed to lose heat.

Russe11

Theres more than one rating system out there, what was rated? the sealed units or the frames or the whole window. Was it rated new? was it rated over a period of time? was the rating for a gas filled unit?

Are you in a highly rated energy proof house? is there any point having top quality windows if you doors are draughty, no loft insulation, cavity walls that are not any good...

Its quite hard to compare windows if you are just going by what the sales people say, you need to find out who supplies the windows, what system they use and get like for like quotes.

jchannon

They use the BFRC rating system

sashman

The point of WER energy ratings is they compare the whole window, glass frames etc against another window of the same size.

Your thoughts that windows don't lose energy is completely wrong.

Single glazed lose nearly 6 units of heat every hour, old dg reduced this by half to 2.8 units. Since2006 the max they can lose (U value) is 2, and since oct 2010 it's been 1.8

That said solar gain helps balance heat loss. Only a rated gains more energy than it loses. With the price of energy everyone has to consider the best they can afford.

Triple may not be more effective. Our experiences suggest three sheets of glass loses too much solar gain. We made a customer 1.4 uvalue windows triple glazed that were only D rated on the energy scale

Try http://www.doubleglazingcompanies.com/knowledge/product-accreditations/WER/3 for more info

Sashman

sashman

Don't forget thick curtains. WER windows are great but a rated and no curtains? I'd have b wand very thick curtains.

jchannon

But if I dont get much sun I wont benefit from the solar gain so is it worth getting A Rated?

AlwaysSomething

I would stop looking at the A/B ratings, and just worry about the U value. As MX5 stated, the rating takes into account several factors, including solar gain. Solar gain has good and bad points. On a cold winter day, a window with high solar gain traps a little of the sun's heat. It might warm your house in the morning, and save you putting the heating on for an extra half an hour. On the other hand, on a steaming hot summer day, that window is going to make your house even hotter. Do you really want this? You might argue that it's no big deal - you can always open a window. That is not entirely the point though. The window still gets credit for all that (unwanted) trapped heat. It all goes into the mix when producing an energy rating. Your B rated window might make your house warmer in winter, and cooler in summer than an A rated window. Just like Sashman said - he made a D rated window that kept more heat inside the house than an A window. It just didn't turn the place into a greenhouse in Summer. If you look for a Low E softcoat glass, you can get a great U value, and you might be able to get a bit knocked off the price because it's old technology now. The glass companies made a great job of lobbying to include solar gain in the ratings so they could push a new product and charge extra for it.
Some of the latest glasses and coatings (as used in A rated windows) are not allowed to be used in air conditioned buildings because they consume too much energy to cool the building in summer.

AlwaysSomething

Sorry, my last replay was way too long and wordy. Here's the short version:
When it's cold outside, and warm inside, that's when you are spending money to heat your house. The window with the lowest U value will cost least to heat the house, and that might not be an A-rated window. Just look at the U value

That's better.