discovery101
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Can anyone give advice on new triple glaze windows please? to replace existing ones.....what to go for, what to look out for etc.
thanks you in advance.
thanks you in advance.
New windows - can anyone give advice on new triple glaze windows please?
- Thread starter discovery101
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1. Don't be fooled by "A rated" or any other marketing hype. Look for passive house certification.
2. Remember the best windows poorly installed will perform poorly. Look to have them properly air sealed to the walls (using airtight tape, not foam)
3. The glazing area of the window is the most energy efficient. Therefore the higher the ratio of glazing to frame area the better.
4. Ask yourself if the window needs an opening (for fire escape, ventilation). If not, then consider none. The fewer openings, the better the window is and is cheaper to produce.
5. Read point 1 again
2. Remember the best windows poorly installed will perform poorly. Look to have them properly air sealed to the walls (using airtight tape, not foam)
3. The glazing area of the window is the most energy efficient. Therefore the higher the ratio of glazing to frame area the better.
4. Ask yourself if the window needs an opening (for fire escape, ventilation). If not, then consider none. The fewer openings, the better the window is and is cheaper to produce.
5. Read point 1 again
NoRegretsCoyote
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For insulation triple doesn't do much more than double.
Fitting is the key.
Fitting is the key.
For comfort, triple (passive certified) does a lot more than double ...assuming of course they're installed properly.
discovery101
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Thanks for the reply.....your thoughts on the following?
U value is 1.3w/m2.k on double glazed & 1.0w/m2.k on triple with passive frames.
thanks in advance.
discovery101
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Thanks for your reply......I take it the frames should be air filled as in passive and not foam?
S
Have no idea what you mean by this. The certification documentation will have all the detail. Basically, the frame needs to be thermally broken and insulated. The devil is in the detail.
True, but there is a risk of wasting money on highly efficient windows if the structure they're going in is in poor shape!
Hmmm, I wouldn't call it a waste of money if you have the money. If one is to upgrade a building element such as windows then should they not strive to do the best they can even if other building elements are not up to an equivalent standard yet? Other building elements can later be improved upon too.
In my opinion, what is a waste of money is to do an inferior job now only to replace/upgrade again in the future. I know, I've done it
discovery101
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ok is passive frames better then foam filled?Have no idea what you mean by this. The certification documentation will have all the detail. Basically, the frame needs to be thermally broken and insulated. The devil is in the detail.
Passive frames come in all guises, so it is not possible to give any definitive answer. As said earlier, ask to see the certification documentation.
I'd call it a waste if it could be better spent elsewhere to improve the overall insulation levels of the house.
Yes, but look at what is required to bring the walls up to near passive levels if that even possible. In this case, if the OP later decides to get external wall insulation done, the new windows will have to come out to be re-fitted within the insulation envelope. Failing to do that will lead to cold bridging and condensation and mould issues, and the increased shading will reduce solar gains needed in passive houses. However, relocating them will most likely damage the windows. Talk to many of the external wall insulation companies and most will refuse to touch the windows.
Much of the existing Irish housing stock will never be able to achieve near-passive energy ratings, so spending more on passive windows will not deliver value for money as they are a relatively small part of the building envelope.
The OP asked specifically about windows. It has now morphed into a discussion about wall insulation etc. All I'm saying is that passive units are far superior to non passive ones not only for their heat retention properties and energy balance but also for thermal comfort (radiation losses effect on skin). This positive benefit is real regardless of how other elements are insulated.
NoRegretsCoyote
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At Irish temperatures the cost in heating from moving from a u-value of 1.3 to 1.0 seems about €35 a year for a normal house.
I won't bore you with the calculations but does this seem completely out?
I won't bore you with the calculations but does this seem completely out?
You absolutely have to take wall construction and thermal properties into account. Walls are often a more significant factor in heat loss than windows. Passive grade windows and a decent but significantly cheaper window will yield pretty much the same result unless the walls are also thermally efficient, which in Ireland is rarely the case.