Oberon

Gas lost within a year isn't going to happen unless there is a manufacturing flaw in the unit - a seal failure.

Gas loss from even the very best seal systems is going to be in the 1% per year range. At that rate by the time the gas is gone, there will be new technology around anyway to replace it with - maybe force fields?

enforcer

oberon,
superspacer conducted a study where the loss was 1% every 5 years.
what about TPS ?the way the gas is inserted and the seal itself,they claim gas is never lost.

Oberon

While last I saw Edgetech advertised 1% per year for super spacer, I haven't heard of their 1% in five year claim, but I have no doubt that they would try to claim that is they thought they could do so.

Schuco claimed zero gas loss and zero seal failure when using TPS. I would assume Force V makes the same claim.

The TPS material used by Shuco/Force V is manufactured by Kommerling. Not all TPS is manufactured by Kommerling. A few years back in Germany there was a significant issue with TPS seal failures in windows manufactured by a Schuco competitor using TPS from a source other than Kommerling.

Interestingly, in Germany TPS is not recommended by some folks for use in enviroments that may be subject to high temperature extremes. Reportedly TPS can begin to "droop" and lose adhesion at 70C (158F), which IG's can easily reach in parts of the south. In those circumstances the German folks recommended using metallic spacers for their "durability" (their word, not mine).

enforcer

in real life conditions to where th tempature hets as high as 101 degree's and as cold as zero degree's, is there really a problem with TPS?

Oberon

I would have no qualms about using TPS in most parts of the country.

I might consider doing some additional research before using it in the deep south or desert southwest.

Also, Schuco only used TPS up to a certain size unit - and I can't remember what that size was - anything larger than that size they used an aluminum spacer.

Metrocom Matt

I sell alot of Simonton windows in the South Texas area... mainly DH 5500 Reflections. I've sold a few of the triple pane (9800 Impressions). They are about 2.5-3 times as much as a dual glazed. In looking at the SHGC and the U-Factor, there is NO hope of the consumer recouping anywhere close to the difference in energy efficiency. Colder climates might be different, but down here, we want heat on the outside.

One of the main reasons for the HUGE jump in the price of Krypton gas last year (according to two of my reps) was the war in Georgia. According to them, Georgia is the only place you can find Krypton... except for Lex Luthors lair of course.

tomstruble

as the argon and krypton leak out of the unit what replaces it? nothing?

Oberon

tomstruble,

Depends. If the inert gas escapes due to seal failure then it is readily replaced by outside air.

If the inert gas migrates thru the seal/spacer without seal failure then it is possible that, at least initially, nothing replaces the gas in the IG airspace. In that case the result is collapsed glass.

Air will eventually replace the missing argon/krypton, but it takes air molecules a good bit longer to migrate thru the seal materials than it does argon/krypton. If a window with collapsed glass was left alone long enough, air would eventually equalize the IG so that it would return to normal. But as a natural process it could take many years to do so.

vinylguy

i would rather and do sell triple pane windows. no tricks or gimmicks i just educated myself on windows and and felt they are better. at least the brand i sell and install!
as with anything some people are cheap and sell cheap and do cheap work as for us we tend to think were better and install better products. also we have very few services with our windows we install.
we install alot of windows every year and have tried them all.
i will give you one window i don't reccomend tho and that sunrise. we tried them and had terrible service from our reprisentitave.

BarryZ

I had a nice passive solar heating effect on my south facing ranch in Michigan. On a sunny day in winter, my house temp would climb to about 74 degrees with no extra help from the furnace.
Then I upgraded all my windows to LowE/Argon and lost most of the Solar Heat Gain Coefficent (SHGC). The furnace runs even on a sunny afternoon to maintain 68 degrees. I really miss the feeling of the warm sun!
My point is, had I known how drastic the LowE cuts down on passive solar gain, I would gladly have paid a premium for triple clear.
PS: the 30ft maples shade the house nicely in summer.

tomstruble

i think about that when i occasionally put in a garden window

Oberon

BarryZ,

There are LowE coatings that are designed for folks who want winter solar heat gain, but unless people know to ask for a high solar heat gain coating then they are almost always going to end up with either a moderate or low solar gain coating - which it sounds like you did.

Unless you live in the extreme northern part of the US (or parts of Canada that are even with or are north of the extreme northern US), a low solar gain coating in a dual pane is going to outperform a triple pane clear in terms of overall energy performance - but free heat is still free heat and as you said, the sun feels so very good on cold winter days.

A clear triple and a dual with high solar gain coating on IG surface 3 will have very similar U-factor performance as well as comparable Solar Heat Gain Coefficient (SHGC) numbers, but the real advantage for the coated IG is in radiative heat loss where it will block about three times as much radiant heat loss trying to escape thru your windows than will the clear triple.

Something that will probably surprise most folks is that in the winter conductive heat loss thru a window actually increases slightly with the addition of a LowE coating. A dual pane clear has a little bit less conductive heat loss than does a low or moderate solar heat gain LowE coated dual pane - but the clear unit has from about four to 20 times (depending on the coating, glass thickness, spacing) the radiative heat loss of the coated unit.

Part of what all that means is that the glass on any coated IG is going to be warmer to the touch in winter - when not in direct sunlight - than will the glass on the triple clear. This can be a significant comfort issue.

And, when using a high solar gain coating, you will also get the advantage of the free solar heat virtually indistiguishable from using triple clear. It will only be noticeable when the sun goes behind a cloud and the clear glass will begin losing heat at a substantially greater rate than will the coated glass. The room with clear glass will start to feel cooler much faster than will the room with the coated glass.

davinci

so lowE reduces heat gain from the sun but prevents it from leacing the inside of a house? i thought argon is what kept it from escaping(heat)?
i am a bit confused as to what lowE actually does?

Oberon

Thermal or heat transfer thru a window is going to be both radiant and conductive. LowE coatings are designed to limit radiant heat transfer thru the glass and argon is intended to limit conductive.

In the everyday world, we directly experience ultraviolet, visible, and infrared light. Different LowE coatings will block different portions of each "type" of light depending on the type of coating.

While UV will fade your carpeting, give you a tan (UVA), cause a "sunburn" (UVB), or may even lead to skin cancer (UVA again), it really doesn't add any appreciable heat to your home.

Visible light can also fade your carpeting and it does add heat to your home, but a window that blocks 100% of visible light wouldn't be of much value, so some folks will suggest tinted glass which does help to keep a home cooler by limiting the amount of light into the home. While LowE coatings perform a similar function, they just do it a lot better than tinted.
Infrared is the primary contributor to heat gain or heat loss thru a window. Infrared is divided into near, mid-range, and far (and it has a number of subdivisions depending on whether you want to change the channel on your TV using a remote, or if you want to spy on an enemy at night, or if you want to study the spectral distribution of a star...and more).

Anyway, direct solar heat gain is "near infrared". High solar heat gain coatings will pass near infrared or direct solar heat gain allowing the solar heat into a home, while low and moderate solar heat gain coatings block percentages of near infrared or direct solar gain.
When you are out in the sun and you get that nice warm feeling on a bright sunny day (appreciated in winter, less appreciated in summer unless you are lying on a beach somewhere), you are experiencing radiant heat gain in the near infrared.

On the other hand, if you are standing next to a concrete wall and you can feel the sun's heat being "reflected" off the wall, you are now experiencing far infrared. It is still heat, and still radiant, and it is going to warm you, but the wavelength (frequency) of the radiation has changed from near infrared to far infrared when the near infrared was absorbed and reradiated by the wall.

All LowE coatings block far infrared, but as mentioned different coatings allow different levels of near infrared to pass thru them.

If a homeowner wants direct solar gain, they can get a high solar heat gain coating that would allow near infrared to pass thru the window, but when that near infrared heat will warm the furniture, the floor, the walls, anything that it penetrates. The near infrared will be absorbed and then reradiated in the far infrared spectrum – which is blocked by the coating and results in solar heat gain in – and heat stays in.

When the temperature outside is 0 and the inside temperature is 70, a clear glass dual pane window will allow about 21 btu/hr/ft² of radiant energy to escape to the outside thru the glass (assuming the window isn’t in direct sunlight). Adding a high solar heat gain coating lowers that number to 5 btu/hr/ft².
A moderate solar heat gain coating will lower radiant heat loss thru the glass to 2 btu/hr/ft² and a low solar gain coating will come in at 1btu/hr/ft².
Given that these are ideal conditions and that there are slight variations in coatings depending on the coating manufacturer.

On the other hand, if you are back on that beach and you are walking barefoot in the sand and you are just short of tears because your feet are being slowly roasted, you are experiencing conductive heat gain. In an IG window, this is where the advantage of adding an inert gas in the airspace since the gas limits the passage of conductive heat transfer thru the IG unit.

Conductive is direct contact thermal transfer. Touch that warm wall from the earlier example and you will experience conductive heat thru your fingertips. And to get a little more technical, the heat that you feel from that wall even when not touching it is going to be a combination of radiative and conductive. Conduction because the air molecules near the wall are transferring heat between them. If you are close enough to the wall you will experience that as well.

In the IG unit, air molecules will transfer heat energy from the warmer glass pane to the colder glass pane – conductive transfer. Argon or krypton or xenon or whatever else they come up with will affect conductive heat transfer thus improving the energy performance of the unit.

Oddly enough (as I mentioned in the previous post), adding a LowE coating actually INCREASES conductive heat transfer versus clear glass in an IG.

Given the same 70F inside and 0 outside that I mentioned earlier, conductive heat loss thru the clear glass dual pane IGU is going to be about 13 btu/hr/ft² but add a LowE coating and conductive heat loss will increase to about 15-16 btu/hr/ft² (depending on coating).

Seems like a LowE coating might actually be a bad idea???

Nope, since in the given scenario the coating lowers long wave infrared radiant heat loss from 21 btu/hr/ft² down to 5 btu/hr/ft² or better (again depending on the coating), thus the overall heat loss thru the IGU is improved significantly when using a LowE coating.

In the real world, a dual pane clear is going to lose in the neighborhood of 34 btu/hr/ft², but a dual pane with a low solar gain coating in the same conditions cuts that loss in half – down to 17 btu/hr/ft². A dual pane IGU with a high solar heat gain coating will cut total heat loss thru the IGU over 41%

And if all that isn’t confusing enough (and long enough), I can ramble on for hours (sorry!)…..

enforcer

Oberon--you are a force to be reconed with ! great info my friend. after knowing everything there is to know about lowE,I now know nothing..lol

oberon, how bout adding nitrogen to an argon filled space? does this keep argon from falling or is it theoretical nonsense that some down and out window salesman will use?

Home Serve

Quite a lesson in coatings and gases Oberon, thank you for posting such information. Seems like our window companies would educate but it seems little goes on except sales gimmicks.

Anyway so what is the high solar heat gain coating going to do to Barry's A/C bill when he replaces all of those south facing windows with the proper glass?

Will there be significant gain?
Thanks,
Dave

__________________
Missouri Remodeling Company with services for Replacement Windows Vinyl Siding and Entry Doors

Oberon

Ummmmm that wasn't exactly my intention!

There are several different ways to fill an IG with gas. The best way is to place the open IG in an air-evacuation chamber that removes ambient air and replaces it with whatever gas or combination that the manufacturer wants to use and then seals the IG.

But what if the homeowner doesn't want a gas infill? Well, IG airspaces work best if they are clean and dry. Ambient air in a window factory in summer is unikely to be either clean or dry. Many window manufacturers build and seal their IG units in the open in their factory trapping ambient air.

Since softcoat LowE coatings can potentially corrode in the presense of moisture or oxygen - ambient air will have both of course - in the event a homeowner doesn't want an argon or krypton fill, an IG manfacturer using an air-evacuation chamber can still replace air with nitrogen which is clean and dry and has no oxygen and which will potentially increase the life expectancy of the unit.

In Barry's case this may not be a major issue since his windows are in direct shade in the summer. But for windows that are not protected from the summer sun, there can be definite potential problems with unwanted solar heat gain.

A HSHG (high solar heat gain) coating is not as energy efficient as a LSHG (low solar heat gain) coating. This is true winter and summer. But in winter the HSHG coating can make up for its energy "deficiencies" because of the potential increase in direct solar gain.

Summer heat gain is a bit more complex than is winter heat gain/loss involving radiant, conduction, and convection heat transfer.

For comparison a clear glass dual pane IG will gain about 186 btu/hr/ft², while a dual pane IG with a HSHG coating will gain about 160 btu/hr/ft², and an dual pane IGU with a LSHG coating will gain about 66 btu/hr/ft².

As an aside, I am using a couple technical references for the numbers. While I work with this stuff in my day job, I don't have the numbers memorized!

Also, I am using IG unit numbers since window numbers will vary (often considerably) based on framing materials, glazing systems, and different manufacturer.

And since this thread was originally about triple panes and I have been using dual pane numbers - triple pane performance numbers in summer or in cooling-dominated climates can become really interesting with some surprises as well.

enforcer

Oberon
. doing gas insert in a chamber is exactly what schuco does with tps interestingly enough.
GETTING TO NITROGEN,IS THERE ANY TRUTH TO ADDING NITROGEN TO ARGON WILL KEEP THE ARGON FROM FALLING TO THE BOTTOM of the pane?

Oberon

Yep, Schuco did fill in an air-evacuation chamber. I would suggest that the significant majority of window companies that make their own IG's don't.

Except at initial fill, argon doesn't settle to the bottom of the IG airspace. Within about 24 hours or so, any gas stratification in the IG is gone and the gases have reached equilibrium within the space - they have fully mixed and there is no more separation of the gases.

A gas fill of 50% argon / 50% nitrogen results in a mixture, not in separate layers of gasses. Very much like adding water to alcohol in a glass results in the alcohol and water fully mixing - there is no separation (alcohol doesn't float on the water, for example).

enforcer

Oberon,
you DON'T suggest window manufacturers follow schuco and fill the ig unit with a gas in a chamber? i thought this was the best way to do it?
as for argon and adding nitrogen;basically it means/does nothing?