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Is there any downside to Low-E 366?

Posted by eleena (My Page) on
Fri, Sep 21, 12 at 13:34

I live in - very sunny, hot and humid - SE.

We are replacing all windows and doors (most likely, with Marvin aluminum clad). I have been told to go with 366 for maximum UV and heat protection. I know it has a little bluish tint but that wouldn't be a big deal b/c I am repainting the walls anyway in those rooms where the windows are sun-facing.

There isn't much price difference between Lo-E II and 366.

I just want windows with the *best* rating for the climate.

Please advise.

Follow-Up Postings:

RE: Is there any downside to Low-E 366?

Lo E 366 is the workhorse of all the Lo E glasses and the energy benefits (and the cost of those benefits) are superior to most of the Lo E products out there. The tinting is actually more greenish than bluish. It's actually a very pleasant tinting in most cases. Where it becomes an issue is if you have either wood framed grids (grills) that you are going to paint white (the side that will lay against the glass on the interior of the home),or if you use a metal GBG (grill between the glass) and that GBG is a white color, or even if you are planning to use white blinds or white shades inside the house. It turns out that the green tinting is actually much darker than it appears. And if you do have one of these conditions (white grill or blind/shade conditions) then you will find that your grill color or blind color as it is viewed from the outside is a very nice, minty green color. I have also heard concerns from some homeowners who have a lot of house plants, that the tinting and UV blockage was significant enough that their plants did not thrive.

Those are about the only downsides I can see. Otherwise it is well worth it to have it.

RE: Is there any downside to Low-E 366?

Thank you!

No, no grills whatsoever.

Would I even need blinds (in addition to curtains) with so much UV-protection?

I may use Roman-type blinds in one room which is facing the backyard, so nobody but us will see them. And I like mint color!

But I have another question. I suspected all along that too much UV protection may not be good for plants. I want to grow plants on the kitchen window sill (if I decide against a garden window).

What glass should I use for that window?

I will not have any furniture, floor or countertop to protect near that window as the countertop will be stainless, the floor is stained concerete and the closest cabinet is ~7' away.

Thanks again!

RE: Is there any downside to Low-E 366?

In your case (i.e. cooling degree dominant) it is all benefit.

Great company in Cardinal and a great glass package.

RE: Is there any downside to Low-E 366?


Plants thrive in the visible light spectrum, not the UV light spectrum. In fact, too much UV can be detrimental to healthy plant growth. Many plants have evolved protection from UV.

From eHow (in itself not necessarily a definitive source, but one of many that are available):

"Various plants may differ in their responses to the effects of radiation such as ultraviolet (UV) light. Scientific evidence does show, however, that plants exposed to UV light are less likely to grow as tall as those growing in regular sunlight. Additionally, UV-exposed plants are likely to have smaller leaf areas and shorter stems. Further, some research suggests that the DNA�genes�of plants can be damaged by UV light exposure, although the way this happens is not as well understood."

I have enclosed a link to Cardinal's residential glass guide. Page 22 discusses LoE coatings and plant growth.

Here is a link that might be useful: Cardinal Residential Glass Technical Guide

RE: Is there any downside to Low-E 366?

Thank you!

Need to do my homework now (i.e., read the guide), LOL.

RE: Is there any downside to Low-E 366?

I defer to Oberon's guidance on this, but perhaps it was because of the heavy tinting, and not the UV blockage that the plants did not thrive. You wouldn't have blinds to block out sunlight but you might have them for privacy. It's not a blackout tinting. I think the Lo E 270 (or 272) would be good for your kitchen window.

RE: Is there any downside to Low-E 366?

Oh, thanks!

I am going to hang curtains for privacy but the original owners had both, curtains and blinds. As we have been in perpetual state of remodeling this house ever since we moved in, I have never used any drapes, except for the LR, so the windows still have the old blinds which I hate.

Hopefully, I will not need any, thanks to Lo-E. :-)

RE: Is there any downside to Low-E 366?

The last two digets in Cardinal's naming nomenclature refer to the visible light transmittance of the product. LoE 366 transmits 66%; LoE 270 transmits 70%. 4 points is not likely to matter with respect to plants (a bug screen would have a much more significant impact)

RE: Is there any downside to Low-E 366?


Many of the Low-e formulations are indicated by either the VT, SHGC, or other data point of the coating/performance.

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