Low E on 4th surface; good or bad?

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Grayson73
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Low E on 4th surface; good or bad?

#1 Post by Grayson73 »

Some windows are achieving a lower U-Factor by adding coating on the 4th surface. Is this a good or bad thing?

I believe this is how the Ideal Platinum 3000 window achieves a U-factor of 0.22 while the Okna 800 DX is 0.26.

Grayson

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HomeSealed
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Re: Low E on 4th surface; good or bad?

#2 Post by HomeSealed »

Good question Grayson. For most people that have a climate where cold weather and condensation can exist, surface 4 low e is not a good choice. It is not inherently bad technology, just misapplied and misused often where the drawbacks outweigh the benefits.

The surface 4 location of low e (inside/interior surface of glass that you can touch) reflects the heat without allowing that pane of glass or the airspace inside the IGU to warm up as much. While this keeps heat in your home, it creates a colder surface which develops condensation more easily. The CR (condensation resistance) rating will drop measurably in that case, typically ending up in the 40's , where a good double pane surface 2 such as the Okna 800 that you mentioned is in the low 60's.

In COLD climates, surface 4 is terrible IMO, and used by folks that are uneducated, shady, or many times both in the worst cases.
In moderate climates it becomes more palatable depending on the details, and in warmer climates it can be a nice option.

Grayson73
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Re: Low E on 4th surface; good or bad?

#3 Post by Grayson73 »

Thanks for the response! Maryland is sometimes cold, but many times mild, so perhaps it's a good choice after all. Sadly, I couldn't find the Ideal Platinum 3000 CR rating, but the Ideal Majestic's is 54. Not sure if the Majestic has surface 4 Low E though.

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Re: Low E on 4th surface; good or bad?

#4 Post by masterext »

Majestic has the option of a surface 4.

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Re: Low E on 4th surface; good or bad?

#5 Post by HomeSealed »

Grayson, it depends on whether or not you care if you have condensation on your windows when temps are below freezing. There are other factors that go into whether or not that would occur of course, as well as how harmful that condensation could be when it comes to adjacent woodwork, indoor air quality, etc. I'd agree that its importance is not as high in MD as it is in WI or say MN, but I've not conveyed my thoughts properly if it came across as anything close to a "good choice" for MD.

Keep in mind, that the above discussion is purely based on the tangible performance issues. Comparing performance in apples to apples glass packages and options will be a good indicator of the quality and engineering of a product as well. I don't know the Majestic line all that well so I can't speak specifically to that product, however for example, if one window has a .26 u value and .01 air infiltration rating with a standard surface 2 coating, and the next has a .28 and .15 AI, the superior performing unit is generally so due to better design and build quality.

Lastly, if you are in an area of MD served by him, I'd be remiss if I didn't recommend Windows on Washington. Top company in that area, great people, and keep in mind that installation is an extremely important factor as well.

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Re: Low E on 4th surface; good or bad?

#6 Post by randy »

I second the recommendation on contacting Windows on Washington. Replacement windows, if well chosen, should be a one-time purchase. Getting the glass package right is critical to your long-term satisfaction with the windows you choose. Windows on Washington has the knowledge and experience needed to guide you through the process.

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Re: Low E on 4th surface; good or bad?

#7 Post by Windows on Washington »

Grayson,

Happy to help with any technical questions you might have. To echo what HomeSealed already mentioned, we don't like this Surface 4's in this region. While we don't get as frigid as the HomeSealed folks do, we do get cold enough.

We see condensation issues even after new windows in some cases. Client are used to keeping blinds closed or having the humidity up higher because the previous windows were, albeit unintentionally, exchanging so much of the home's air that they were drying out the home. We have had clients call us that they NEW WINDOWS are sweating and at which point I ask them to check the relative humidity and its through the roof high.

Seen too many surface 4 windows with the condensation issues to recommend or even attempt them. There was a time when Okna considered it as a standard option, but given that much of their business was concentrated in the NE, they quickly moved away from that option.

If you want the ultimate in performance, there are some triple pane options to consider. Didn't used to be on the radar for this area 7-10 years ago, but we see and install a bunch more of it these days. Folks seem to love it when the house is so temperature stable and they don't have the little cold sections of the home where they have a bank of windows.

Feel free to ring me with any questions.

Eric

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Re: Low E on 4th surface; good or bad?

#8 Post by Grayson73 »

Thanks, Eric. Greg Schwartz from WoW came over last week. I assume he's your co-worker?

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Re: Low E on 4th surface; good or bad?

#9 Post by Windows on Washington »

Greg is our lead sales consultant, yes.

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