roof lantern triple glazing worth it?

[Gazman16]

Roof drafts?
I was standing in one of my conservatory's yesterday in the 100+ MPH winds and not a peep of a draft.
Mind I do tend to seal everything

 

[s60tsy]

theres normally a gap in the ridge that air can pass through, id didnt mean draughts as such. Most roofs have parts that are not thermally broken and not much seperating the inside and outside eg bottom of the sheets

 

[andrewf75]

i manufacture roofs and we do a roof that can accomodate the 36mm glass units, we have done quite a few. The gains from triple glazing may be lost with the roofs draughts etc. id say get the best dg 24mm glass for the difference in price compared to money saved along time

Hi, thanks for the reply

So you mean draughts where the lantern is fixed to the upstands? Is there any way of preventing this?

and surely those losses would still be there with double glazing as well?

I'm slightly confused...

This is the lantern I was thinking of getting
http://www.reflexglass.co.uk/triple.html

 

[s60tsy]

im just not sure if the gains for 24mm to 36mm would be worth the price difference.

 

[andrewf75]

im just not sure if the gains for 24mm to 36mm would be worth the price difference.

OK, thanks, but in terms of u values its twice as efficient. Down to 0.6 from 1.2. I'm confused as to why insulation seems to be all about u values but no-one seems to think its worth halving the u value in a piece of glass covering a huge part of the roof! Presumably the roof is where a large part of the heat would be lost from a room.[/b][/i]

 

[s60tsy]

the glass may have a good u value but the roof holding it in place is not part of this, the gains may not be as good as they look on paper

 

[andrewf75]

Thanks, but as I understand it the u value includes the frame as well. I guess its where the lantern is fixed to the flat roof where some losses could happen.

 

[s60tsy]

u value is the glass only

 

[s60tsy]

ill rephrase that before i get shouted at, the u values you have seen seem to be just for the glass

 

[andrewf75]

ah thanks, I thought when it had w/m2 it was the frame as well, will have to find out the whole unit

 

[s60tsy]

best to check, because a poor roof will not help

 

[andrewf75]

Just discussed the lanterns woth reflex and the triple glazed has a whole unit u-value of 1.0 (glass only is 0.6) and the double glazed is 1.4 (1.0) so I'd say the triple glazed is a pretty big difference and it doesn't seem to be a poor roof.

Its only £300 extra so I'm thinking may as well go triple, will probably make that back in heating bills over the years.

 

[ey143]

Does anybody rate Roofmaker Ltd as a decent supplier of roof lanterns?

 

[andrewf75]

as my old thread has been ressurected, I got it from a company called Lumina design in the end. Great product (and didn't bother with triple glazed - double is completely fine in our climate)