Hey folks,

I'm going to be breaking ground this fall to build a new home here in Maine. I've decided to reduce the size of the house significantly from what I originally thought I needed, so I can justify going with a better built home with higher-end finishes, etc. I'm also committed to building a home that's very energy efficient, well-insulated and forward-thinking in its construction.

I've decided to go the route of triple-pane fiberglass windows with a good R-value (R-6). I'm considering two options and am quite interested in hearing of people's experiences with each. They're both Canadian companies. One is Fibertec (www.fibertec.com) and the other is Thermotech (http://www.thermotechfiberglass.com/index.htm). Both brands of windows are on the expensive side as windows come, so I don't want to make an impulsive decision about which brand to go with. [Please Note: Thermotech in Canada is not related to Thermo-Tech Vinyl Windows in MN.]

Is anyone out there using either of these fiberglass windows? How do you like them? Were they worth the extra money? Have you had any problems with them or the company? What was your experience like getting the windows made and delivered?

Thanks in advance for your input.

John

John,
I am anxious to see the answer to this question as well. I have looked at both too.

Any reason you wouldn't want to use an American company, such as Comfort Line FiberFrame out of Ohio? I'm a residential designer and am specifying them for an ICF house I'm currently working on. My own ICF house (in Virginia) has Inline out of Toronto—great window, LOUSY service (from the MFR, not the local distributer). Anyway, the East Coast options are still limited. So I found Comfort Line and the specs appear to be good. Plus, there's the issue of the weakening dollar. 2 cents worth...

I have been looking at all the windows mentioned here in this post. I heard from a dealer of Comfort Line brand that they have started to stray away from the window manufacturing and are focusing more on the patio enclosures. So I left them out of the equation based on the dealer's input. I'm just about ready to send out the bid documents to fibertec, inline and thermotec. I think price will be the deciding factor in the selection process. Hope this helps, good luck.

I wouldn't necessarily go by what a local dealer said. I spoke just last week with both the Comfort Line corporate office and a regional distributor and got NO such indication that they were giving up on their windows (and doors). Dealers may say such things only because they want to redirect you to the primary brand(s) they carry.

I spoke with a guy named Matt Frahm at Comfort Line today who actually suggested buying my windows from Fibertec instead! Apparently Comfort Line furnishes Fibertec with their lineals. His suggestion was based upon the fact that Comfort Line doesn't sell direct-to-consumer as both Fibertec and Thermotech do, and I made it clear to him that I'd like to buy direct rather than having to pay a cut to a middleman (who probably sells these windows once a year and adds no value to the process.)

Comfort Line windows may very well be great, but I'm not the least bit impressed with the company. Also, their website lacks the U-factor and SHGC info that you can readily access on either Fibertec's or Thermotech's websites. You have to jump through hoops to get it from them. It's just not good business.


John

Living/working in Minnesota, I've heard a lot of good feedback on Thermo-tech windows (the brand from MN, that is).

I wasn't aware that another brand exists with the same name!

From what I hear though, Thermotech's fiberglass windows are definitely superior to Thermo-Tech's vinyl ones.


John

Good info to know, John. I will make sure bidders on my project know about the Canadian options—though it will still be interesting to see how prices compare with Comfort Line.

Skia_d:

For the record, I just got an Excel file from Comfort Line with all of their U-factor and SHGC info for their windows.   Their numbers---even for Krypton-filled triple-pane low-e windows---are noticeably inferior to Fibertec's and Thermotech's.

Just make sure when you get pricing that you're comparing apples-to-apples.   The absolutely most thermally-efficient window Comfort Line makes is a triple-pane Krypton-filled 'picture' windows, with a U-factor of 0.18 (R-5.6) with most of their Krypton-filled windows being in the 0.20 (R-5) to 0.24 (R-4.2) range.  

Comparatively speaking, Fibertec has a double-pane Krypton-filled window with a U-factor of 0.10 (R-10).   Yes, an R-10 window.

Hope this helps,


John

John,
We are building in Indiana and after much research are also planning to use triple pane fiberglass windows. I saw your post on another site, then found it here, and was very interested to see what response there would be. It is relatively easy to learn about windows in general (frame material, spacers, coatings etc) through NFRC and other very informative websites, but difficult to try to determine the real life track records of specific brands from someone other than the manufacturer. We have been looking at Thermotech, Fibertec, InLine, Comfortline and Accurate Dorwin. So far, I've been most impressed with the information I've found for Thermotech, InLine and Accurate Dorwin, although it is admittedly little information. You might be interested in one item I found regarding Thermotech and Fibertec: http://www.passivehouse.us/passiveHouse/Articles_files/EDU%20May2007%20Postable.PDF
Sorry that I'm just tagging along with your post and not really providing information, but you've asked the same questions we have and I'll look forward to hearing what windows you decide to use.

Swmal:

Thanks for the note and for the link to the PDF. I was familiar with Katrin Klingenberg's original Passivhaus, but not this most recent one. It was particularly good to learn about this more recent structure and to hear of the owner's experiences with windows---specifically her views on Fibertec vs. Thermotech. I've heard of one other person who had similar experiences with Fibertec's windows, but you hate to make an assumption based on such limited information. The guy I've spoken with at Fibertec---Steven Hall---has been terrific and has assured me that most of the problems that have existed in the company's past have been ironed out. But who knows. It looks like this second Passivhaus was completed in late '06, which really wasn't all that long ago. . .


John

John,

I don't know either company, but someone cited to the thermotech windows the other day.  I read through some of the articles that they have on line, and found them interesting.  This one seems to relate to your high R value choice. 

http://www.thermotechfiberglass.com/Column2.htm

Good luck!
Larry

I just read the article ReadytoRetire mentioned. It's a wee bit deceptive in that it makes it seem that somehow their LOF glazing is superior. This one comment tells it all: "Note that the location of the Low e surface is different for the two options, but reflects where most manufacturers put the coating." Oh, really? When I ordered my Inline windows, I was asked to specify which surface to put the coating on. Surface 3 of course, based on my geographic location. On Cardinal glass. This is not a matter of Thermotech having better glazing, it is a matter of knowing the currect surface to specify for the coating. The example comparison in the article was NOT apples-to-apples, and Thermotech should be ashamed of the deception—if they really are a high-class company they ought not try to separate themselves from the competition in such a way. They should let their product and services speak for themselves. A more helpful article would explain what surface to put the coating on and why.

So, i'm the guy that wrote the article.

For those that haven't read it - in summary it says;
Windows are not walls. Windows are not only a source of heat loss, but also a source of heat gain. In the north,  best insulating value, doesn't necessarily result in the lowest heating bill.

While i've never claimed to be perfect, and it's been almost 10 years since i wrote the thing (some minor edits a few years ago, and probably needs a few more...), i think it holds up well.  In short i don't think it's deceptive.

Although i haven't looked lately, it is my understanding that most North American manufacturers still put their solar shading low-e on the #2 surface. I agree some don't. Some even offer a choice (even better). .....And just as most is not all, some is not most.

Putting a solar shading low-e on surface #3 instead of surface #2 does increase its solar gain -- it improves the ER about 2 W/m^2. This is not enough to bridge the gap of about 10 W/m^2 mentioned in the piece.

Yes, i agree the location of the low-e coatings can make a difference, but the type of low-e coating (solar gain/ higher SHGC or solar shade/ lower SHGC) makes an even bigger difference.



Stephen Thwaites P.Eng.
Thermotech Fiberglass Fenestration

Stephen,

I'm glad that you responded.

Did you run out of time to write, or are 10 years worth of articles posted somewhere else?

VERY respectfully,
Larry

Larry,

http://www.thermotechfiberglass.com/news.htm

This link takes you to the page on their website where you can access other articles written by Stephen..


Dave

I am building a house for a customer in Salisbury, MA, using the Thermotech windows.  If you want to look at the windows, I show them on the south side of the house in a slide show at this address: http://greendesignbuild.net/CurrentGreenProjectsWeAreWorkingOn.aspx  They are VERY heavy, as they are big, and they are triple paned glass.  We needed to install them with a lift gate on the back of a truck.  Several hundred pounds each!  Other than that, they seem to be performing well.  At this point, we are about to install closed cell spray foam, but even without the insulation, the house has been quite comfortable even on cold days with the sun out.  These windows are about R-10 depending on the loaction in the house.  And they have a SHGC of about .55, again, depending on the location.  They seem to be performing quite well.

One option I would consider though, is the Alpen windows: http://www.alpeninc.com/windows/index.htm  They have one combination with an R-20 center of glass rating!  However, as the rep told me this particular window has a green tint to it, which might be objectionable to some.  However, they have windows in the R-15 range that appear quite clear.  This is better than most modern "energy efficient" walls!  And then you add to that, that they absorb solar energy, even on the north side of the house.  So, in reality they perform far better than walls.  The rep told me you could expect to pay between $40-$55 per square foot, depending on configuration.  It seems to me that this is well worth considering, especially with energy price's constant climb into the stratosphere.  If you calculate the payback at today's energy prices, you will have to keep shortening the payback period every time the energy prices go up.  It's a no-brainer!

You may want to consider H Window too. Less money, better window. (www.hwindow.com)

Pringstrom:

I checked out www.hwindow.com.    Both the windows and the website seem mediocre at best.    They're extruded aluminum.   No fiberglass to speak of.    Thermal performance looks to be pretty middle of the road, too.

How did you conclude that these are better windows than what you'd get from Thermotech or Fibertech?    You don't happen to work for these folks, do you?


John