ot drilling glass

Some do. Lots fail before then. Abus & ad hominem only shows your inability to discuss rationally.

rnal, meaning air access to the units is from outside not inside. Thus they are exposed to the lower water vapour content outdoor air. Such setups alm ost never mist, and when they do they clear promptly.

g else nowadays. As a result we have sealed units that can be filled with f ancy gases for a little extra insulation - until it leaks out. And when the seals go... it's new unit time, or drill them etc.

are the solution exists, and the dg companies aren't ever going to profit b y mentioning it. So inherently faulty designs are the norm. So much so that UK BR actually require that now.

Almost all window loss is conduction, or in some cases draughts. If house i nteriors were red hot it'd be different.

NT

On Sunday, 26 March 2017 12:44:38 UTC+1, snipped-for-privacy@gmail.com wrote: NT:

It's far from dry in lots of places, including England. It doesn't need to be dry for dg to not mist.

NT

om:

or leak rate

Air conditioning makes

.com:

ok

I would think that once the seal is holed it'll all leak out whatever it is in a relatively short space of time.

NT

I'm not sure what you were going to say, but ac makes no difference to mist ing of the design I mentioned. As long as indoor temp is at least as high a s outdoor, outdoor RH can be anything and it won't mist. Misting only ocurs when indoors is colder AND outdoor is very close to 100% RH for long enoug h for condensation to build up. Those conditions seldom happen.

NT

Don't forget convection. This is why the standard spacer is 12mm - it's a tradeoff for convection/conduction with air or argon.

The radiation transfer is made lower with low-emissivity coatings, which can go down to e=0.03. Argon also protects the coating.

I don't know if the coating reached the production, but one company had reached emissivity of 0.015. They had trouble measuring that low..

Window glass (like other oxides) is completely opaque in the thermal IR, so the radiation loss depends only on the temperature of the outer pane.

Cheers

Phil Hobbs

Never been to New York in the summer, I gather. ;) It's commonly 30 degrees warmer outside, and of course 100 degrees and 90% humidity means a _lot_ of water in the air. Houston can have weeks in a row of weather like that.

See Point 1. ;)

Cheers

Phil Hobbs

CO2 has a gamma in the range of 0.3, compared to diatomic gases at 0.41, monatomic gases around 0.6. Gamma is a measure of the relative rotational energy of collisions, which matters, according to Phil (and I'm inclined to trust him!).

Monatomic gases don't carry any rotational energy (that are visible in their collisions at ordinary temperatures).

If Xenon is the champ, that'll be the high molecular weight. I suppose that helps, though I can't see why. Or maybe it's just easier to contain?

Lots are installed improperly or have been damaged along the way.

When you lie, expect to be called on it.

I did wonder about a plumbed DG system with an aquarium pump & tiny dehumidifier. If misting starts, run the pump for an hour. Easy to do at new build, less so for retrofit.

NT

OK, I don't need to take you too seriously in future.

Oh, I'm so disappointed!

I did some more looking and it looks to me ( I may have misread some charts ) that one could use freon R134a and cut the thermal conductivity in about half of what one gets with Argon.

Dan

Pity about the global warming potential. It doesn't attack the ozone layer, but Europe has already banned it as a greenhouse gas.

ion?

the kT (~25 meV) range of energies. More complicated molecules have lots of rovibrational states in that range, so they transfer more energy per co llision, which makes them disappointing as insulators.

with Argon instead of CO2. My copy of the Chemical Handbook has CO2 as be ing slightly better than Argon as far as thermal conductivity. I would not think that there is enough moisture that carbonic acid would cause problem s.

Huh.. should be cheaper too. From here,

"You?ll notice that krypton has the lowest thermal conductivity of the bunch; unfortunately it is rather expensive, so is only used in a small percentage of the most energy efficient windows (particularly triple-glaze d windows where the thinner space between panes allows a smaller amount of the gas to be used). Carbon dioxide has low conductivity as well, but can b e reactive when it meets moisture, so it?s not suitable for a glazi ng gas. Argon is the next best gas"

George H.

Right, I have no idea where convection starts... (some delta T vs separation?) But once it does seems like any advantage of Argon will be lost.

George H.