Low - E & Plants

For all those Replacement Window decisions - just read, review or post a question. You will be helped!
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ppj
Posts: 18
Joined: Fri Mar 17, 2006 1:43 am

Low - E & Plants

#1 Post by ppj »

Does anyone know if Low-E coating affects flowers and plants?

Does it affect it by blocking U.V. Rays?

Thanks for you help.

Oberon
Posts: 119
Joined: Tue Dec 13, 2005 8:57 pm

#2 Post by Oberon »

LowE coatings block light in the ultraviolet and infrared spectrum. Plants like light more to the center of the visible spectrum.

There have been several studies on LowE and plant growth and actually many plant varieties that are UV sensitive actually thrive with LowE windows.

Of those that are not particularly UV sensitve, LowE does not appear to be a factor at all.

As an experiment, place a plant in a closet with nothing but a black light (UVA, 365nm)...the plant will die.

researcher
Posts: 79
Joined: Wed Oct 05, 2005 9:11 am

#3 Post by researcher »

[Quote]...many plant varieties that are UV sensitive actually thrive with LowE windows.[End Quote]

Oberon, I learn interesting things from your posts, thanks for sharing.

I wonder if you could answer this question for me. What is the reason for using a gas mixture of 60% Argon and 40% nitrogen in a dual pane, and is the 60/40 by weight or volume? I have read or heard four answers to this question and they all differ. Hope to hear what you have to say.

Oberon
Posts: 119
Joined: Tue Dec 13, 2005 8:57 pm

#4 Post by Oberon »

Interesting question - and one that has several answers (and opinions)depending on who you ask.

Not everyone agrees that 100% argon or krypton is the best way to fill an IG space (I am talking about the folks who decide such things for their respective window companies).

For various reasons some people believe that a gas mixture is actually advantageous over a pure gas when used as a fill. Some people mix krypton and argon, some mix in SF6 or sulfer hexafloride, and some might prefer and use other gas mixtures for various reasons.

When a person buys a window with "air" rather than a "refined" gas infill, the IGU in that window could be actually filled with 100% nitrogen rather than room air. Obviously this only works if the IGU is filled in a vacuum/pressure chamber, but when dealing with coatings or when concerned about the dryness or cleanliness of the IGU space then adding a processed gas rather than simple room air could be considered an advantage. Nitrogen is cheap, plentiful, non-reactive, and easy to work with.

In the case of a 60/40 argon/nitrogen mix, the folks who determine such things at the window company may be satisfied with the IGU insulating performance at the level of 60% argon fill. In other words, they believe that the additional expense of taking the unit to 100% argon fill is simply not justified by the level of the improved performance. Consider the cost/benefit ratio when there are still folks who question the value of a 100% argon or krypton fill in either energy benefit or cost benefit analysis.

As mentioned, if the unit is filled with less than 100% argon or krypton then it would be counter-productive to complete the fill with room air...so a mixture of argon and nitrogen is used for the complete fill.

Some folks might fill to a 50/50, or to a 70/30, or an 80/20, or even to a 90/10...it all comes down to the window manufacturer's preference based on their testing and benefit results.

I believe that the ratio would be based on gas volume - but I would have to check with a couple of sources to verify that.

researcher
Posts: 79
Joined: Wed Oct 05, 2005 9:11 am

#5 Post by researcher »

Thanks Oberon

Your answer makes sense; it is based on what makes sense....to the particular window manufacturer as to; is the small gain worth the extra cost it would entail to the customer.

af145
Posts: 4
Joined: Wed May 03, 2006 2:02 pm

#6 Post by af145 »

Oberon, I was wondering how Low E and argon filling affect flowers and plants. Thanks for the Low E explanation; what about argon? I didn't think it mattered much, but one of the window salesmen told me that plants die behind argon-filled windows. He said it happened with one of his customers.

So, what's the expert's verdict here? Thanks in advance!

mman
Posts: 49
Joined: Fri Apr 14, 2006 1:51 pm
Location: Portland, OR

#7 Post by mman »

First of all, great posts Oberon. Do you have any sites, specifically, that talk about this. I was always lead to beleive that the light blockage may be bad for some plants. Thank you.

Oberon
Posts: 119
Joined: Tue Dec 13, 2005 8:57 pm

argon

#8 Post by Oberon »

af145,

I admit I have never heard that one before. I am inclined to say that the window salesman was sampling some of his own plants when he made that particular statement.

I can think of no reason that argon would have any effect on plants and I am always skeptical of anecdotal "evidence" anyway. I know that some window salesfolk will occasionally try to discourage potential customers from argon - for a variety of reasons - some even believe what they are saying - but this one is a first.

I can think of no reason why argon infill would have any effect on plants. It doesn't affect the light spectrum which is really the issue in this case I would think...I will ponder this one for a while I suspect.

mman,

Not off hand. I might suggest that you google uv, low-e, plants, etc. and see what pops up.

Light blockage in the right frequency range would certainly be bad for plants, but LowE isn't blocking light in that range. LowE blocks UV and IR and lets the visible light pass thru...

If you were using a heavy tinted LowE coating I might watch the plants a bit, but typical LowE or LowE2 has been tested a lot and it does not cause a problem.

af145
Posts: 4
Joined: Wed May 03, 2006 2:02 pm

thanks!

#9 Post by af145 »

oberon,

Thanks a lot for an opinion! I did google on those subjects a few days ago, that's how I found your post regarding the low-e. After my post, I did some more digging and saw a few notes from plant-lovers -- all of them saying that argon has no effect on their plants. So I guess I will simply dismiss the salesman's testimony. Thanks again!

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