DG or TG windows??

jakko86

Hi all in the process of building a house and getting window quotes and I'm unsure of which to go with, I have no north facing windows, so I'm wondering does solar gain with DG outweigh the benefits of TG in terms of heat loss? House will have hrv so no vents on windows. Any help on this would be great.Is there anything else to consider?

fclauson

DG or TG - can you clarify what you mean by these terms

rockabaloo

I'd assume Double Glazed and Triple Glazed.

jakko86

fclauson wrote: »

DG or TG - can you clarify what you mean by these terms

Ya sorry double or triple glazed?

kieranhr

I've often compared Double-glazing and Triple-glazing in DEAP (the BER software) and the TG may save a few percent in overall heating costs. Very rarely saves a full 5%. It doesn't cost much to step up to TG, maybe 15%, but it doesn't make a significant difference either. My opinion is there's better places to spend your money, on isulation or HRV, etc.
The one place I do recommend TG is for noise reduction, with habitable rooms close to a busy road for example.

Certified

Its not a simple matter of saying triple is better than double as it all depends on the glass used, the gas used, cavity widths, spacer bars used etc.
It also depends on where the glazing is going to be positioned, will it get direct sunlight etc.

The selecting of the glazing should be undertaken following advice from your energy consultant.

kieranhr

Yes, very true. I should have qualified my post by saying that it's based on a U-value of around 1.2 W/m2K for double-glazing and 0.7 W/m2K for triple-glazing. Those are whole frame u-values, as opposed to glazing u-values, and I would expect to achieve these or better when buying new windows nowadays.

sydthebeat

kieranhr wrote: »

I've often compared Double-glazing and Triple-glazing in DEAP (the BER software) and the TG may save a few percent in overall heating costs. Very rarely saves a full 5%. It doesn't cost much to step up to TG, maybe 15%, but it doesn't make a significant difference either. My opinion is there's better places to spend your money, on isulation or HRV, etc.
The one place I do recommend TG is for noise reduction, with habitable rooms close to a busy road for example.

one of the real positives about triple glazed windows is one thats hard to compare mathematicaly... but its the 'comfort' factor.

• standing next to a single glazed window, the adjacent temperature is around 1°C
• standing next to a double glazed window (manufactured in the year 2000), the adjacent temperature is around 11°C
• standing next to todays low-e double glazed window, the adjacent temperature is 16°C
• standing next to a triple glazed window, with a centre pane U value of just 0.65, the temperature is 18°C

Theres no thermometer as sensitive as human skin....
you 'feel' colder the closer you are to double glazed windows compared to triple glazed

kieranhr

Another good point by Syd there. Anything more than a 4 degree temperature differential is perceived as a draught by human skin. You'll get that 4 degrees with double-glazing, but not with triple.
Yet another advantage is that you'll get little to no condensation on a triple-glazed window as compared to double-glazed. Though that shouldn't be a consideration if you have a proper ventilation system.

jakko86

Thanks for yer advice, front of the house is facing ENE and I have the conservatory to the southern end as well as kitchen and living room, there is 2200 in the difference between double and triple glazed, Just trying to figure is it worth the extra for the triple glazed.

sinnerboy

jakko86 wrote: »

Just trying to figure is it worth the extra for the triple glazed.

Most likely to be one of those cost-me-extra-but-glad-I-did-it items.

jakko86

Thanks eveyone for yer help and advice.

about2build

recently moved into my treble glazed window house and its heating capacity when the sun is shining irrespective of external temperature is palpable but more over that I have had a track machine working outside in garden last few morning and it hasnt woken me....they are almost impermeadle by noise and a great advantage. cost me 2000 extra on 34 pieces of window