We're having a new back door. It has [i]about[/i] 0.5 sq m of glass.
If single glazing costs ~£40 and double glazing it costs ~£120, how long will it take to get the money back for double glazing.
2 years.
why the requirement for the new back door? Did you get your old one smashed in?
Depends, are you paying for it outright or did you take a loan?
I'd get 2 lot's of single glazing and save yourself £40
Also bear in mind your comfort... Depending on the layout on the house side of the door, the difference in feel could be noticeable and make the extra money money well spent.
I read somewhere (possibly here) that when you're doing heat transfer calcs, for a single glazed window you you an equation that involves heat transfer through glass while for double glazed the equation involves heat transfer through air (or whatever is in the window) and you ignore the glass as insignificant!
Not possible to make such calculations as it depends on too many variables. £120 seems a lot for a door glass in DG, get more quotes.
I read somewhere (possibly here) that when you're doing heat transfer calcs, for a single glazed window you you an equation that involves heat transfer through glass while for double glazed the equation involves heat transfer through air (or whatever is in the window) and you ignore the glass as insignificant!
You can find the U-values quite easily, but this won't help calculate the financial savings without knowing a lot more, starting with how much the op is currently paying, size of the glazed area etc. The cost of calculating all this will easily double or triple the cost.
If the rest of the house is double glazed, double glaze it. If not, get the whole house double glazed.
Double glazing should not be considered in terms of payback, you'd never have it done. 😐
get it unglazed, and then go to your local glass merchants,and say, " i want a double glazed unit made." you need the size width and height, also very importantly, [u]the thickness[/u], this will be a multiple of 2, the glass is 4mm, so you've got 8mm, then the space could be anything from 10-20mm. specify the colour of space bar you want, (the metal bit inside the window you can see, normally silver. easy, and should cost about 20-30 quid. good luck with finding out the thickness measurement, it is critical. to fit it you need 2 little plastic spacers, get them from the glass shop, and a soft hammer. put the unit on the spacers, to keep them up off the moisture that collects, put the plastic beads in, the last one will be tight, pop the corners in first, then tap it with the soft hammer.
Not possible to make such calculations as it depends on too many variables. £120 seems a lot for a door glass in DG, get more quotes.
It's 6 small panes which I think pushes the price up. The guy doing it will just pass on the cost of the glass to me but if he's over-estimated the cost of the double glazing he's probably over-estimated the single too so the sums should still work out.
It is currently the only single-glazed bit on the back of the house. Most of the front of the house is wooden framed single glazing (and in a conservation zone). Come the big lottery win, I'd like to get the [u]properly[/u] replaced.
Much as it pains me to say, I'd go for the single glazed if you're concerned about the cost.
😥
One door won't make a jot of difference to your energy then, go single.