A Window for us New Englanders?

9 years ago

I'm looking to replace two windows (in finished attic), most likely in the spring of 2015 and really love all the info. I'm reading about OKNA windows.

I'm trying to learn as much as possible about windows and didn't see coming of all the types, options, and Energy Star numbers...etc.
Now that I've acquainted myself with all the U-Value, SHGC, VT, AAMA Rating, Air Infiltration numbers (to name a few), it's hard to find a window for us New Englanders that need a higher SHGC (Solar Heat Gain Coefficient) rating.

I'm thinking of going with the OKNA 500 (or 5500 depending on if I do a full frame replacement...I don't want to lose window area).
I want the MOST natural light as possible.

The Dual Glazed Clear Glass seems to be the best option with it's 0.60 SHGC and 0.63 VT (Visual Transmittance).

If I go with the window with the Energy Saving Package (Low-E), then my SHGC drops to 0.30 and my VT drops to 0.54, letting in less light and reducing FREE solar heat in the winter.

I don't use air conditioning in the summer so the heat gain in the summer would be pretty much the same (if not a little lower) than the 20 year old Weather Shield windows I'm using now.

All the info. I'm reading is for us in the Northern parts of the US, should use windows with a high(er) solar gain but there aren't any.

I just came across WASCO windows while writing this and they have a LoE 180 Glass by Cardinal and they say:

WASCO's standard Solar Gain glazing is tailored to Wisconsin's climate, where heating loads dominate our energy bill. This glass has a high solar heat gain coefficient (SHGC), which allows in passive solar heat, reducing annual energy costs in our heating-dominated climate. This free renewable energy more than offsets the tiny increase in heat loss over low SHGC glazing, and yields better overall energy performance. This package is standard on all WASCO windows.

EnergyStar (TM) has calculated that an increase in 0.05 in SHGC is worth a decrease in U-Factor of 0.01 Btu/ft2Ã¯Â¿Â½F in our northern climate. WASCO's engineer has independently verified this tradeoff, and LoE 180 glass does even better!

Cardinal LoE 180 reduces radiative heat transfer out of your house, while allowing free solar energy into the house, reducing heating bills.

Two layers of double strength glass, 3mm (1/8") thick, along with SuperSpacerÃ¯Â¿Â½, keep WASCO's windows extraordinarily quiet.

Now has anyone dealt with WASCO windows and are they as good as OKNA?

I want a low profile frame...the most amount of window and least amount of framing around it.

Could WASCO be the answer for those of us that want a high SHGC?
It seems they are more of a "local" company Southeastern Wisconsin but they have shipped to Vermont.

UGH! This is frustrating.

Can anyone shed any light on this subject? (no pun)

Comments (12)

PRO
Windows on Washington Ltd
9 years ago
Don't get too mired in the numbers.

The short answer is that any reduction in passive solar heat gain are going to be accounted for with massive reduction in radiant heat loss during the heating season.

This is why I recommend triple pane to folks as a default now. 99.99% of the consumers out there do not have a Passivhaus style home that is built or intended to take advantage of passive solar.

Unless you have interior finishes that are designed to absorb and store (dark finishes with good thermal mass...i.e. stone, tile, etc.), the result is going to be negligible.

Now...I don't want a dual pane window with Low-e 3 (i.e. 366 or 5527) but double pane Low-e is fine and triple pane is still good.

The coating that Okna uses is perfect for your region and again, I would recommend triple pane in your area.

Yes...you will have less passive solar but you will have much less radiant loss.

I can't comment on the Wasco window but I assure you there are better window with the Cardinal Low-e 180 if you are looking.
georgect
Original Author
9 years ago
Thanks WoW...I think I understand what you're saying.

It's just strange how a lot of web sites are saying we need to still have a higher SHGC in colder climates.
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PRO
Windows on Washington Ltd
9 years ago
...ideally....yes.

Is your home designed optimally to take advantage of it...? Not in about 99% of the cases that I see.

If you want to go with Low-e 272 on the South facing elevation, that should be more than good enough.
Karateguy
9 years ago
The wasco window is nothing special in any regard, not in the same league as Okna by any measure. Cardinal 180 glass is widely availble in many products (all those that offer Cardinal glass), and those that use an alternative glass manufacturer have a similar high solar gain option.

WoW's recommendation is spot on regarding this glass package. It is excellent in the proper application when a home and its surroundings are designed to take advantage of it, however as mentioned, it will be less efficient if improperly applied. For the typical home, a good balance between moderate+ shgc and great u- factor is ideal. It looks like Wasco is trying to capitalize on "something different" to offer, and disservicing their clients in the process. This is no better than those companies that offer a very low solar gain glass package in a cold climate just to "artificially" get a better u-factor. Again, not the most efficient option overall and they know it.
georgect
Original Author
9 years ago
@WoW...(or anyone with experience with OKNA windows and FULL screens).

How do the full screens attach to the out side of the window?

I know they have a standard locking half screen but I would opt. for the full screen...how do they work?

Does anyone have pictures of how the full screen looks and fits into the outer most frame?
toddinmn
9 years ago
The full screen would sit in the same channel as the 1/2 screen and mounts the sane way. They are more difficult to take due to size and not as much clearance on top and bottom.
georgect
Original Author
9 years ago
toddinmn...

Sorry but I'm totally inexperienced with how OKNA mounts its screens.
For 20 years my Weather Shield have had the type of full screen that anchors by the way of four spring pins that secure it to the surrounding frame.

I easily take them out and store them away for the winter.

How does OKNA secure its screens to it's frame?
And I'm I going to have a hard time removing them for the winter.
Do they have tabs or some kind of catch mechanism or are they just forced in place?
PRO
Windows on Washington Ltd
9 years ago
Still mounts in the screen track but with a larger flange as compared to setting inside the screen track groove.

They then use and interior plastic clip that locks it to the track.

They have gone through a couple of iterations but this one seems to be the favorite for customers.
georgect
Original Author
9 years ago
Thanks WoW.
georgect
Original Author
9 years ago
Follow up:
I emailed OKNA about a higher solar gain window (LoW 180) and the don't offer that BUT they are coming out with some sort of a higher solar gain window. It may be out in a month or so.
PRO
Windows on Washington Ltd
9 years ago
Low-e 7138 (Guardian) is just fine for this region to be honest.

I would be more interested in a triple pane and high efficiency unit as compared to looking for passive solar.

Unless the home is built for it, you will not get the max or desired effect.
georgect
Original Author
9 years ago
Yep, I hear you WoW.
I just wanted to pass on the word in case some here ruled out OKNA because they don't currently offer a higher SHGC that could benefit from it.
Now they will have an option (in a few months from now).