The last number I heard was that krypton is currently about 600 times the cost of argon. Using krypton in a large window can become very expensive.

In order to achieve the maximum effectiveness of krypton you need a narrow airspace between the glass - roughly 1/4" or so.

How big is the largest individual sash in this garden window?

In a really large window, a very narrow airspace can become a problem because there may not be enough room between the lites to avoid them touching during changes in barometric pressure - this may be worse in a triple than in a double.

Depending on your environment and on the level of energy performance that you desire, using argon (double or triple) in a wider airspace can result in very similar energy performance numbers, compared with using krypton, often for a good bit less money. And a wider airspace (1/2" or so) is better in a larger unit.

Ultimately though, the gas infill is a good deal less important than is using the right LowE coating on the glass.

With the LowE coating you can control the level of solar heat gain thru the window (from a lot to almost none) and keep "regular" heat inside your home in winter and outside in summer.

Porchguy,

Thanks a lot for your info!

Do you know what is the approximate price range for installing

1. a garden window with triple pane, double lowE with Kripton gas, or
2. a garden window with double pane, double lowE with Kripton gas.

Do you have a recommendation for a company or brand of the window? I am in WA.

Thanks.

oberon,

Thank you very much for the reply!

Do you have approximate price difference between a 72' X 46' double pane Garden Window filled with Krypton and Argon gas?

The largest individual sash in this garden window is the front sash. I do not have the number with me, probably 70' X 40'? Is it considered really large?

About solar heat gain through the window, what is the difference between a double LowE and single LowE coat?

Thanks.

Hi Mary,

Pricing for the window can vary significantly between different companies, so there really is no way to directly compare pricing without direct apples to apples comparison. My point was that it might be worth your while to compare options to krypton fill before making your decision.

I would consider a window at 70"x 40" to be large - not extraordinary - but not undersized either.

Low-e coatings can be divided into high solar heat gain, moderate solar heat gain, and low solar heat gain; and there are two types of LowE coatings, hardcoat and softcoat.

Typically, hardcoat and single-silver softcoat LowE are considered to be high solar heat gain, while dual-silver softcoat are considered moderate solar heat gain, and triple-silver softcoat are considered low solar heat gain.

The choice of coating may depend on where you live, the orientaton of your windows, and what works best for you.

And depending on the window manufacturer, you may or may not have a choice on the LowE coating that is available.

Mary,

Here in the Northeast, I've had good success and customer satisfaction with the Alside brand. They may have an office near you. You'd have to check.

But, please note that there are plenty of GW mfgrs. around
the country.

A 6' x 4' GW probably weighs in at about 300lbs. If custom made to fit under an existing beam, on the first floor the rate is 800.00.

Second floor or higher, add about 400.00.

If have to alter the proposed window opening or creat a completely new opening, then you need a new beam, jack-studs and all; could add another 800.00 to the total bill.

Oberon definitely knows his glass and please consider his comments when choosing your new Garden Window.

All the best,

The PorchGuy

Here is a link that might be useful: My Album

I have examined the value of using Argon or Krypton in low-E glass. Basically, because there is only a 20% reduction of U for the Argon, the savings are not much, at least in my climate of 4500 net HDD-CDD/yr. Using a heat pump with a cooling COP of 3.5 and an electricity cost of $0.12/KW-hr, and a dealer cost of $40 to put Argon into a window of 25 ft^2, I figure that the annual reduction in energy use to be about 1% of the cost - well below the cost of financing or opportunity cost. I'm sure the reduction to Krypton is even less, with the net cost of Krypton being much higher.

As I don't see energy prices getting too much higher (before energy costs would really skyrocket, if we didn't have enough solar or wind power to suffice, we'd start burning coal). it just doesn't male sense. Perhaps in Minnesota, with much higher HDD, the number may barely make sense. But then there is the problem with leakage.

With all this said, the low-E is definitely worth it (although just barely for my climate, and definitely for higher HDD climates.)