New windows are double paned and filled with argon so block heat loss. Wouldn’t it be better to “fill” them with nothing. Argon conducts some heat. A vacuum doesn’t convect any heat. So why not thermos bottle windows?
Wouldn’t the vaccum cause the window to be a little more prone to breaking?
Pressure. 14.7 pounds per square inch on the glass. It would shatter. Look how small and thick airplane windows are - you’d need to build house windows like that if you had air pressure on one side and a vacuum on the other.
You could solve that problem with little spacers, but then you wouldn’t have nice clear windows. Maybe we’d do that if the effect was dramatic, but it’s not. If you had a pure vaccum it would only increase the R value of the window by a few percentage points.
Also, you’d have to build really good seals into each window. With equal pressure of argon on the inside, all you have to do is build a seal good enough to prevent migration of the material. With a vacuum on the inside, the seal would have to withstand significant pressure.
And to anticipate the next question, they use argon specifically because as a noble gas, it’s monatomic, rather than diatomic like nitrogen or oxygen, which makes it less conductive of heat. And they use argon rather than some other noble gas (like helium or neon) because it’s by far the cheapest one, being the third most abundant gas in the atmosphere.
I thought Argon was use over Helium as Helium leaks out too easily. Is this incorrect or just too simple?
Jim
Argon gas is also dense. So it circulates slower, reducing conductive losses. Helium would be a lose.
Of course, in this modern age we can sputter-coat single-pane glass so it’s more energy-efficient than double-layer glass.
Sputter-coating is, basically, when the glass lites are run through a vaccum chamber where ions are shot at a bar of coating metal. An ion-sized piece of that metal is dislodged and goes looking for someplace else to be - namley the surface of the glass. One of the materials that can be coated onto the glass is glass itself - which make it super-smooth and needs less cleaning.
Now, if only the hurricane states would pass building codes that require Low-E single-pane glass, we could (1) remain competetive in the domestic production field (at least until foreign producers figure out coating as well as we have; (2) reduce energy consumption from air-conditioning (3) halve energy consumption by shipping coated single-panes insead of double-panes.
Problem is, the other side of this argument has lobbyists in Tallahassee saying “well, every year has a hurricane, so when the glass breaks, better to just replace it with more cheap shit.”
Yes, that’d be true, also. But I suspect that the price is the overriding factor (and is certainly the reason they don’t use krypton or xenon).
FWIW, some divers use argon in their drysuits because it’s denser than air (those are air tanks recreational divers use; not ‘oxygen tanks’) and they say it keeps them warmer.
Wanna bet?
I’m curious:
- how does an extra layer of ions make a single pane more efficient than an insulated double-pane unit?
- why is this especially relevant to hurricane states?
Sulfur hexafluoride too. I even get some hits on uranium hexafluoride double panes.
To clarify my post; I only stated that single-pane saves energy from air-conditioning. There is a slight reduction in heat loss in the winter using coated vs uncoated glass, but not appreciable.
(1) It isn’t a layer of ions - but rather the atoms of bombarded material they displace that coat the glass
(2) The relevancy to hurricane states is this: coated glass keeps houses in the Gulf Coast cooler in the Summer = saving air-conditioning = less oil used at power plants = fewer KIA’s in Iraq (I swear, can any thread topic not be turned into a Bush-bashing?)
Besides coating, glass can also be laminated to withstand all but the strongest winds. (This has the advantage of less broken glass flying around during storms and laying around afterwards)
These advantages are currently not mandatory in Florida, which has a penny-wise/dollar foolish allowance for cheap, often foreign, uncoated and unlaminated glass use in their building codes.
If anyone’s interested in the science of all this coating & argon-fill & laminiation stuff, here’s a link to my company’s pdf booklet
Very little electricity in the US is generated by oil burning plants (and most of those are in Hawaii, IIRC) - most comes from coal, nuclear, natural gas, or hydroelectric plants.
I still don’t get this, and frankly, don’t believe it. Can you explain the physics behind your statement?
I presume you’re trying to say that coated glass will block or reflect more radiation from entering the house during the summer, but that only applies to windows directly exposed to sunlight with no curtains or shades. Overall, I would imagine that a typical house, with windows on all four sides, roof eaves, and curtains or shades would easily be more energy efficient with double pane glass in all the windows. This would apply to a much greater degree in winter, providing even more efficiency.
Your company makes Prision loaf and puts that were the windows used to be?
WTF? Over.
how about a real link this time? 
I 'unno. Light bulbs manage it with downright flimsy glass. The somewhat spherical shape helps, I wager.
Light bulbs (I assume you are talking about the incandescent variety) these days are usually filled with a nonreactive gas like, well argon, rather than vacuum. Bulbs containing a vacuum were more common many, many years ago.
True enough. Some vacuum bulbs are still being produced, typically low-wattage models.