One for Biff really.

Whats the minimum spacer for a 4mm k glass unit which is Argon filled. I need to stay with as slim a unit that will pass Building Regs.

2nd opinion anyone?

It's a barn conversion for a client and the main contractor has used multi foil (oh dear!) Harrogate are passing tri iso 10 now!

I've fitted all the windows with the usual 'k' glass + 16mm air space, I want to fit slimmer units in my 48mm doors because going to a bigger section door profileof 63mm just seems wrong. I have 38mm rebates and could shoe horn 24mm units in there, but I like to add 2mm flexi strip either side and I hate stepped beads...... I'm pretty sure Biff Vernon mentioned something about going slimmer with an argon fill on the old forum, but can't find it. 4-6-4mm as mentioned above would be cool as I can stretch to say 4-12-4mm , but wheres the data to keep the inspector happy?

We have finally managed to track down a local glazer who has not only heard of edge seals with a thermal break, but has actually used them. However he has been persuaded that argon fill is a waste of time due to leakage.
As most on this forum seem to advocate argon fill, does anyone know of any studies/info I can show him to prove otherwise?

Hi Richy
He came highly recommended from friends as a straight talking and fair bloke and comes across as such in person.
Most of the glaziers around here seem to think argon leaks out and is thus a waste of time, but his chief influence seems to be someone from the BSI which from a quick google search seem to be the people who have issed his kite mark.
He seems adamant (reading between the lines)that it is a waste of time on the basis that he doesnt want comebacks which will detract from his good reputation.
High performance glazing is very new in our area as far as local suppliers are concerned and those I have spoken to dont understand the need for anything beyond K-glass.

For existing dwellings and extensions: http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADL1B_2006.pdf
Paragraphs 18, 19 and 20

and for new build:http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADL1A_2006.pdf
Table 2 [page 19]

Note the limiting u-value of 3.3W/m2K

To put some figures on options[calculated via software]:

4/6/4mm [k glass/air/float] will give you a u-value of around 2.1W/m2K. Substituting argon for air will bring it down to around 1.6W/m2K - Not bad at all.

Posted By: Mike George4/6/4mm.

I doubt it. Should that be 4/16/4mm?

I don't know anything about software, but I do sell double glazing for a living, and if a 4/6/4 igu with Pilk K and argon fill has a centre pane U of 1.6 then I, and many others, are sadly mistaken. That is about the figure I would quote for a unit with a 16mm gap, but not with 6mm.

<blockquote><cite>Posted By: biffvernon</cite>That is about the figure I would quote for a unit with a 16mm gap, but not with 6mm.</blockquote>

Yes, my mistake. Here is a pilkington brochure which gives their calculated values http://www.pilkington.com/resources/brpartlglassandbuildingregulations.pdf

[Table 2 page 4]

I would still like to know of software which calculates window u-values. The download I tried from buildesk does not. Anyone?

Posted By: richyIf he's saying the gas can escape from his units, doesn't that mean they can also suck in moist air causing condensation between the panes?

Not necessarily - different gases diffuse at vastly different rates. I've understood that Argon diffuses much faster than the other gases that make up air (78% Nitrogen, 21% Oxygen, 1% Argon, 0.033% CO2); however having had my first look at the Periodic Table in decades, I see that Argon (40) has a much larger molecular weight than Nitrogen (14) and Oxygen (16), so what's happening here - anyone explain? Also Nitrogen, Oxygen and air's conductivity (0.024W/mK) compares with Argon's (0.01772) and Krypton's (0.00943).

BTW, do we realise how little CO2 there is up there, considering all the fuss?!

FRAME 4.0 was the whole-window software used by manufacturer Hajom Fonster as supplied by Swedish Window Co (both now sadly defunct) in 2001. These tables http://i30.photobucket.com/albums/c301/fostertom/hajomcalcs.jpg, http://i30.photobucket.com/albums/c301/fostertom/hajomcalcs001.jpg make interesting reading.

If oxygen presently comprises 21% of air (the figure was higher in older, more energised human times), here's this, from http://mistupid.com/chemistry/aircomp.htm:

"The air that leaves a person's lungs during exhalation contains 14% oxygen and 4.4% carbon dioxide.
Atmospheres with oxygen concentrations below 19.5 percent can have adverse physiological effects, and atmospheres with less than 16 percent oxygen can become life threatening."

So, as, apart from marine fauna, most of our oxygen is produced by tropical rainforests (which split that 4.4% CO2, so as to make that 14% O2 back up to 21%), of which an area the size of America still exists, and is being burnt at the rate of one Florida per year, let's hope that ............ well, let's just hope!

Flora, not fauna, yes. I did read that the tropical forests put the temperate ones into the shade (!) in photosynthetic significance. A tropical giant has 14 acres of leaf surface, against 4 acres on a full-size temperate and the solar radiation there is several times stronger. And the sheer wall-to-wall size of the tropical forests compared to the scattered gappy temperate forests. The point is, the 4.4% CO2/14% O2 exhaust of a typical fuelburner, whether human or industrial, has to be restored to 21% O2, and all animal life is solely reliant on the plants to harness solar energy to split that CO2 back into carbon and oxygen.