Need recommendation for a window company
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We would like our patio French doors to be both R-5 and very well sealed. Can you recommend companies that make such doors and a sidelight to our front door that is of high quality like Marvin (and would look like a Marvin) but for less money? Thanks!
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Karen,
An R-5 door (U-0.20) is a tough standard for a patio door. (Presumably, you're talking about the U-factor of the entire unit, not just the glazing.) It certainly requires triple glazing.
I would check with a Canadian company that makes fiberglass windows and doors. Two that I know of are Thermotech fiberglass and Inline fiberglass:
http://www.thermotechfiberglass.com/slidePatio1.htm
http://www.thermotechfiberglass.com/slidePatio3.htm
http://www.inlinefiberglass.com/products/600patiodoors.html
http://www.inlinefiberglass.com/products/downloads/600patiodoors/600%20Series%20Specs.pdf
The Thermotech unit can be ordered with one type of triple glazing that achieves a whole-unit U-factor of U-0.21, equivalent to R-4.76. That's quite good, although it's not quite R-5.
By the way, I think you may be dreaming if you think you can get a triple-glazed patio door unit with the best thermal performance on the planet "for less money" than a run-of-the-mill Marvin.
I am looking into Thermotech doors too. The website is very limited in terms of information so, it will be very informative to call them and ask questions and to get their data sheets so you can know the data on the glaze as well as the frame.
I saw a Thermotech door swing patio door in person last month, it has a multi-lock system to ensure a tighter seal. The sliding patio doors are not as tight as the swing doors. I also heard that Marvin makes a lift and slide patio door now. It's great but the glass is not great.
that's all I know so far.
We went with a sliding patio door from Serious Windows. My memory is that the U factor is .17 for the whole unit. A year ago it was about $1000 less than the standard French door unit that our lumberyard quoted us on with much better performance. I've heard Serious' prices have increased since then.