0 Helpful?

Are uPVC windows a good or bad idea at 7000' elevation and high solar insolation?

I am considering the purchase of Intus eForte windows for a new house. The windows would have be transported over several mountain passes up to 11,000 ft and then be installed at 7000 ft. This would require pressure relief valves that would vent the argon gas. Does this degrade the performance of the PH certifide window and would it become uncertifided? Also, the dealer recommends white or similar light reflective colors in Southwestern states due to the fact that darker colored PVC will expand and contract more causing more stress on the IGU to frame seals since even white PVC expands and contracts more than glass. White PVC is not what I want in the new house. (I tore out the white PVC windows in the current house and installed aluminum clad wood) Even though Intus is reasonably price, a house load still is a considerable investment and I'm very concerned about the two negative mentioned. Any one have experience with this problem?

Asked by Chuck Jensen
Posted Jul 17, 2014 9:29 AM ET


6 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.

The information you have provided is correct. There is no way that I know of to transport sealed IGUs (insulated glazing units) from a sea-level manufacturing plant to a high-elevation mountain location without losing the argon.

You can inquire at a local glass shop to find out whether there are any companies that assemble IGUs near your job site. If the IGU is assembled at a high altitude, you're all set. You can contract with a local glazing shop to install the IGUs into window frames purchased without glazing.

White vinyl will have fewer problems with expansion in hot weather than dark vinyl. Obviously, if you don't like white vinyl windows, don't buy them.

Answered by Martin Holladay
Posted Jul 17, 2014 9:55 AM ET
Edited Jul 17, 2014 9:56 AM ET.


Transporting windows across low to high elevations and across mountain passes is down all the time. The manufacturer, in this case Intus, would install breather tubes within the glazing to equalize the pressures that the windows will face. Here in the southwest it has been done thousands of times, no worries, no problems. The elevations out here change by the minute.

The loss of argon would have a minimal impact on the glazing U-Value. One can calculate what it would be but it would be very minimal and will not impact the PH certification. Remember, even the non-certified Intus uPVC triple pane windows are still installed in many homes that become Passive House Certified.

As far as the PVC color goes. White is the standard color but they offer upgraded colors and the laminates they offer actually protect the PVC frames. They use a special modified laminate that is factory applied and this laminate will deflect the suns UV rays and reflect the heat. The pvc frames are reinforced with a steel u-channel and remember, the glazing unit in an Intus Window is a floating unit and it is not part of the PVC frame. In essence what this means is that the glazing will contract and expand at its own rate and the frame will expand and contract at its own rate without compromising the seal between the glass the frame. The glazing is held in place with floating gasket on all sides and that is why the assembly is so air tight <0.03 cfm/ft² but the different materials can move as they choose without compromising the seal.

Like you, I was worried about the elevation (I'm at 5,000 feet) and the UV but after much research, there is NOTHING to worry about. Get the laminate color you like and don't worry, these Intus Windows are not your run-of-the-mill vinyl windows, they are top-quality engineered windows. Like you, I also don't want white frames so I opted for the laminate colors. The laminate they use is found here: http://www.renolit.com/exterior/en/brands/renolit-exofol-fx/

Here is some info on the laminate colors they use on the frames:
RENOLIT EXOFOL FX is a multi-layer film with an overall thickness of 170 - 180 μm. The top layer consists of a polyvinylidene fluoride film (PVDF), the second is transparent polymethylmethacrylate (PMMA) and the base layer is a solid colour PMMA. The base layer contains Solar Shield Technology (SST), to further decrease heat build-up of the film and the laminated components.

The 3-layer construction of the film ensures colours, retain their brilliance over the entire life of the film even when exposed to intense UV radiation. Because of Solar Shield Technology, RENOLIT EXOFOL FX protects profiles against excessive heat build-up. As a result, RENOLIT offers a guarantee of up to 22.5 years for this product – up to 15 years as a warranty on the film and another 7.5 years via RENOLIT's proprietary renovation service.

Answered by Peter L
Posted Jul 17, 2014 2:56 PM ET
Edited Jul 17, 2014 3:00 PM ET.



Wow, thanks, I really appreciate you sharing your research on the Intus windows. That's some new information and good news. I was starting to have doubts about the uPVC and the next option was to spec aluminum clad wood PH windows which is considerably more dinero. I will get the darker color I like and not worry. I think I will also take another look at the specs on the Arcade windows since I am not persuing PH certification at this time (too far out in the sticks - expenses).

Answered by Chuck Jensen
Posted Jul 18, 2014 12:25 AM ET



Here is a link showing the Architectural laminate colors they use:

I prefer the White Aluminium but the Thorium Grey & Grey Aluminium are nice also. You should request a color sample piece before you finalize a color. Seeing it in person is always better than a computer monitor since the color settings are never exact on a computer screen.

What color were you looking at getting?

Answered by Peter L
Posted Jul 18, 2014 11:15 AM ET



I had speced the Basalt grey which is a dark grey and that was my concern about expansion. I also like the Thorium grey and my go with it. It would be nice to see a real sample. The Inoutic website colors look different than the Intus website colors. I don't think the dealer has samples though.

Answered by Chuck Jensen
Posted Jul 19, 2014 9:53 AM ET



I would go with the Thorium or any color within the Architectural Laminates. The RENOLIT EXOFOL FX 3-layer laminate film is what you want. The Renolit FX laminates are what protect the PVC. I would make sure that the color you spec out is part of that Renolit Exofol FX laminate series. The MX, PX and MT are decent but the FX is the top-of-the-line film made for extreme climates like yours.

They should have samples as that is a very common request. I would contact the dealer and request it. You have to see it in person to make a proper decision.

Answered by Peter L
Posted Jul 19, 2014 12:13 PM ET
Edited Jul 19, 2014 12:38 PM ET.

Other Questions in Energy efficiency and durability

High-R Wall Design in a Wildfire Zone?

In Energy efficiency and durability | Asked by Will Welch | May 25, 18

Mitsubishi hyperheat multi-splits and modulation

In Mechanicals | Asked by Aun Safe | May 25, 18

Best Value Mini-Split for Cooling, Some Heating?

In Mechanicals | Asked by Lance Peters | May 26, 18

Insulating Wall Between two Different Slab Elevations

In Green building techniques | Asked by Jonathan Lawrence CZ 4A New Jersey | May 24, 18

Purchasing/DIY single mini-split

In General questions | Asked by Emerson | May 25, 18
Register for a free account and join the conversation

Get a free account and join the conversation!
Become a GBA PRO!