South glazing low emissivity or NOT?

[lolus]

Hello

in a straw house that I am starting to build would it be interesting to put glazing with just argon gas to allow the infra red of the sun to heat the interior.

What you will need to know is whether the IR input outside will be greater than the heat loss by radiation from the inside but that I have no idea.
My heating will be initially just wood then solar floor probably thereafter

do you have any idea on the question ????

[Christophe]

The low emissivity relates more to a possible surface coating (4-season glazing) on ​​the faces of the glass than the gas between the glass.

In any case, you need quality double glazing.
The question is to know if it is interesting to pass in triplicate, and in the event of a southern facade, the answer is no ... in our latitudes: from South East to West it is preferable to put double glazing (there is a diagram explanatory "compass rose" in the links below).

The triple limit too much intake.

To read:
https://www.econologie.com/forums/le-triple- ... t4570.html

https://www.econologie.com/forums/double-tri ... t4711.html

And do a search: https://www.econologie.com/forums/search.php

[Korben Dallas]

In the book by JP Oliva and S Courgey "La conception bioclimatique", there is (page 114 of my edition) a comparative study between different glazing solutions (single glazing, and several ranges of double glazing, none of triple glazing. ) depending on the orientation of these highly lossy walls.

Even in the south, the best solution is double glazing with reinforced insulation, added with insulating shutters Uw = 1,5 W / m2.K

For your information, a glass wall of 3m2 on the south side is around 375 kWh collected free of charge per heating season, roughly the energy released by a 1000 W radiator, that's not nothing.

[Christophe]

Even in the south, the best solution is double glazing with reinforced insulation, added with insulating shutters Uw = 1,5 W / m2.K

Especially in the south you wanted to say no?

[Korben Dallas]

No, "even in the south", because in the north, the question does not arise: the ideal is to avoid glass walls in the north and when you have no choice, you have to use triple glazing or less efficient double glazing + insulating shutter.

[lolus]

in fact to simplify my esitation is not between double triple argron or not but especially low emissivity because I have the impression that behind a window with low emissivity it is cold even in the sun

a priori I am wrong if I trust to tell you and to those of jp oliva to whom I rather trust in these studies ...

so it will be weak emissivity ...

[loop]

Bonjour,

Here is my feedback

I replaced the old ep 15 glazing (4-7-4) on roof skylights, 45 ° due south
I mounted instead of ep 24 (4-16-4) low emissivity glazing, through which the light appears slightly bluish

My big problem of overheating on the summer floor is solved
In winter, the glazing is more insulating, so it leaves fewer calories and the IFs escape
On the other hand, the solar gains in the winters are almost blocked, but I do not live in a very sunny region anyway during this period (this is an element to take into account when talking about the passive gains in the winters )

A+

[Did67]

I confirm the looping saying: the low emissivity "blocks" the entry of solar energy.

I also installed 4 Velux "low emissivity" (with this slightly bluish colortaion) on the south side of the attic that I have fitted out.

So, in good weather in winter, you have to chuaff anyway.

But in my case the priority was to make it "viable" in the summer ...

So if the objective is to recover as much heat as possible (in winter and in the off-season), low emissivity should not be taken (in any case not the treatment used by Velux). Double glazing or triple glazing, OK, solar energy passes through and is “captured” inside.

With low emissivity, a part is pushed back outside. In summer, it's a plus. In winter and off-season, a minus ...

So "letting in" also supposes the capacity to store this acquired heat (therefore sufficient slabs and heavy interior walls to have thermal inertia). A priori, for the slabs, this will be the case because if you say future solar heating, that means that you are drowning the coils in a heated floor ...

This presupposes above all a solution to manage overheating in summer: "cap" above the openings, exterior "leafy" greenery, shutters and blinds ...

[Korben Dallas]

Attention: do not confuse sensation and reality.

If you do indeed have the impression that the sun heats up less behind an IR double glazing, it is a sensation.
If you go outside to assess the heat loss between the inside and the outside, it would also be a sensation, but of course very difficult to perceive.

The book I cited talks about actual MEASURES performed. He concludes that the solar gains, EVEN in the south, are lower than the losses when the sun is absent.

If you have contrary figures, I am ready to examine them.

[Did67]

OKAY.

1) I do not dispute the difference "feel" and "measure" ...

2) that said, it is not necessarily contradictory. In other words, very often, a feeling of warmth is either synonymous with higher temperature or warming of the skin on the surface ... Even if we agree, it is more complex. And even if temperature is not synonymous with energy !!!

3) I don't dispute the book that you cite either ...

4) but I'm not sure we are talking about the same thing.

Basically, double glazing (or triple for that matter):

a) can be passed through, in both directions, by radiation which “transport” energy (not only visible, but also IR, hence the interest of closing shutters and curtains at night); and this more or less depending on whether the glass (or more exactly the surfaces) are low emissivity (it passes through less) or not (it passes through more) ...

b) is allowed to pass through heat by conduction; more or less, in particular according to the thicknesses, thickness of the air klame and the fact that it is air or argon ...

So for me, "the best solution", it depends:

- if I want to prioritize the "gain of calories" (in winter): opt for a maximum of insulation (therefore triple argon glazing) but to low emissivity; but in this case, watch out for radiation in summer (I know what I'm talking about, I have about 25 m² of south-west facing French windows, with "normal" double glazing) - the question must then be dealt with ( screens, shading, shutters ...) ...

It's my choice for the living room. With overflow by a balcony + electric shutters.

- if I want to prioritize the freshness in summer (it's my choice for the attic): double or triple glazing + low emissivity ... But I have to heat more in winter (on sunny days, I don't capture as much radiation - and it feels on the skin; that's what I said; it also feels on the floor, which heats up less).

That's what I'm trying to explain. Without numbers.

Or if you want, that the "most positive result" is not necessarily the best choice (if the maximum calories gained is not what you are looking for the most) ...

I don't think I am contradicting a bioclimatic "pope"?