Alright, I’m sure I could find some discussions on this in the Archives, but I would like to gather some fresh ideas. I’m in the process of planning a house and initial cost is of concern. I was told, at one time, that double hung windows are more efficient than casment. Then the other day, the same building center employee told me that casements are the most energy efficent.
Which one is actually better with energy efficency???? Where could I find specific facts regarding this?? I know I can compare U – Factors, but that is simply the glass performance, right??? Not the entire window efficiency???
Specifically, i’m looking at Marvin Integrity windows, as the local dealer sells them and I have had a decent experience with them in the past. I would appreciate any facts regarding this.
upnorthframer
“If you think education is expensive, try ignorance!!!”
Replies
Discuss it with your Integrity dealer. A few things speak "efficiency" when looking at window performance.
One is air infiltration, another is heat loss, and there's one more, solar performance.
Marvin has test report documentation on all these, and your dealer can help you decide.
As regards air infiltration, logic would tell us that a casement leaks less air, because it has less "crack length" of weatherstripping than a doublehung window. But the doublehung design might have double rows, neutral pressure zones, and other things in its design, that might make it leak less air than a comparably sized casement.
Only your window manufacturer knows for sure.
Casements are like a door. They close into a gasketed frame and there are locks to pull it in for a tight fit. The problem with casements is they sag over time, heavy glass in a light frame. This can effect how they fit in the frame and contact the gaskets. Even the best windows are poor energy savers compared to a solid insulated wall. Window Quilts. insulated drapes or curtains make a big difference in cold climates, regardless of the type of window.
Beat it to fit / Paint it to match
With double hung theres a chance of balance spring problems. Casement may have alignment or latching problems. Casement are chosen to meet egrees codes.
There are double hung units that meet egress codes - tho in general they must be wider and taller than a casement in order to meet most egress requirements.
If egress is a concern, check with the local municipal and state codes for egress window requirements.
Edited 5/17/2007 2:23 pm by Jen
Most window catalouges have an indicator such as an asterisc of bolder lettering to indicate which of their units meet egress codes. Neither DH nor casements are more likely to meet codes there. It all depends on size and style of the window.If I were facing a high wind zone, I would consider the casements more efficient against infiltration.
if I were trying to ventialte a house using open windows a lot instead of AC to cool it, I would consider DHG windows more efficient, if used correctly.
There is no one size fits all rule.
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Upnorthframer, I have heard that the casement window is almost always superior to double hung windows for reduced air infiltration. Another casement advantage is that you can choose which side the hinge is on and thus funnel wind into the house from the prevailing or appropriate direction. A casement window will meet egress standards with a smaller overall size than a double hung.
I am thinking of using the Marvin Integrity windows on my persoanl home. I like the durability and rigidity of the fiberglass frame and the wood on the inside. I understand that the Building Scientists think very highly of the fiberglass frame.
You should also consider the style of your home and which type window is more appropriate.
Be careful on egress assumptions...it's the net opening code enforcers look for, not the gross opening or sash size. Also, check the SHGC numbers...and, if you're trying for some passive solar heat gain, might want to go with clear glass on the south, and that makes for different numbers.An Energy Star certifier can take your plans and steer you in the right direction.And, the Integrity casements seal quite well. Outside of the gates the trucks were unloadin',
The weather was hot, a-nearly 90 degrees.
The man standin' next to me, his head was exploding,
Well, I was prayin' the pieces wouldn't fall on me.
"the Integrity casements seal quite well."Quite right! One criticism of casements other than style is that they tend to sag over time and become difficult to operate. I think this is more true of the vinyl ones than of wood. I have worked on wood Andersens forty years old with none of that.But the Material Integrity uses for frames is so stable that I do not see it becoming a problem.
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upnorth
generally the casement will be more energy efficient..
to me the esthetic design and ease of use is my my primary consideration
don't forget the little details.. like screens inside on casements.. and outside on DH
handing and prevailing wind direction
eave overhangs
passageways in the swing of the window
etc, etc
aight- most of the posters on this site will recommend the marvins. You can go to the nfrc website and learn all about fenestration and how to tell which windows have the best ratings.
I encourage you to spend your money on the permanent things like windows. This will pay for itself in the long run.
that being said, you need to see the windows before you buy them, and you have 3 components to worry about. The frame, the seals and the glass package. IF buy quality in these areas window style wont matter. If you like DH's, if you like Casements it dont matter as long as you buy quality.
Watch out about Low E coatings if you have indoor plants, it can prevent them from getting what they need.
-worth exactly 2 cents!
I had heard that DH with storms is the most efficient. Then casements. Then DH alone.
I have not facts to back up this claim.
Making egress req's with DH makes for BIG windows, but that is not necessarily a bad thing.
I like the screens on the inside of a casement, and the pricing in my case was better for casement than DH.
From an architecural standpoint, I think DH would have looked better on my house, but the size for the upstairs BR's would have been crazy BIG for the room size. We went with a combo of fixed, casement, and awning.
All in all, a new window of either type should seal well. The energy differences between modern and new versions of DH and casements is probably negligible.
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Thanks for all of the input. One thing I saw mentioned a few times was that the casement has the screens on the inside. do you feel this is an advantage??? I have casements on my own house and , living in the country, have grown to get frustrated with the fact that I trap many bugs between the screen and the glass when i close them at night. nothing worse that mosquitos buzzing between the glass and the screen all night. just my 2 cents
upnorthframer
"If you think education is expensive, try ignorance!!!"
I think the tradeoff regarding interior screens is that they are easier to install and are less exposed to the elements.
If there was a difference I'd bet it would be insignificant. So much so, that I wouldn't sacrifice the aesthetics of the design to do so. Choose the type that is appropriate for the architectural style of your home.