U values for windows-Rationel

shakeydude · 19-04-2008 03:01PM #1

Hi,

I was looking at rationel windows and the U value for the glass is in the region of 1.2 W/Sqm K. I thought that they be able to comply to the Passive Standardss of 0.8 W/Sqm K. Am I missing something here, or do the rationel windows have to be treated further to achieve the necessary rating. If you look at Tomas O leary's passive home in Wicklow he would seem to have rationel. Any help is appreciated.

Shakeydude

holdfast · 19-04-2008 03:34PM

the glass may be 1.2 but you need to inlcude the frame and thsi maqy increased the overall u value. you can get what every glass you want but what the passive house design allows up to do is increase the insulation of the walls etc. to achevie the overall max spacing heation of 15kw/m2 per year. but in most cases triple glazing with is the standard.

sinnerboy · 19-04-2008 05:06PM

google SEI passive house suppliers

you will find very high performing window suppliers there ( 0.7 )

expect to pay + 50 to 60 % over windows at u value 1.1

U values for windows-Rationel

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