Improve the insulation of windows: blinds, curtains, blinds?

[phil12]

"So it says" in winter, closing the shutters as soon as night falls allows the house to be better insulated. Opening them when the sun is warm brings in a pleasant and free heat ".


A big step forward for humanity, thank you !!!

[Obamot]

So teach yourselfExpress [...] because I (we) did not understand the same thing ...

Well I forgot to watch the T ° this evening, Christine closed the curtain too early without warning me

Well I didn't take a picture but I looked from time to time and it went up to 15.9 ° C on the tablet for 19.5 ° C on the thermometer side.

Curtain closed it quickly (less than 20 min) dropped below 15 ° C. It is at 19.2 - 14.2 ° C there.

Temperature average, it was not expressed well enough?

Otherwise, assuming you have a constant room temperature of approx. 20 ° C, with an average outside temperature of –7 ° C *, your curtains will save you 0,5 of coef U over all the losses in the room (ie the delta for a window of the type shown is counted WITH curtains). The curtains do not represent more than 10% with the ladle in the best conditions imaginable for a window of 2m X 2m of surface (in view of your photo: metal frame and seals doing their job properly). Either on ~ 500 W of total losses through the window, your curtains will save you ultimately 50 Watt.

As an example, if we calculate the movement of the air mass in a construction: 10% is gaining more chouilla the "natural" renewal of the air in the room (coef U ~ 0,35 always ladle ...). But it is so obvious (until now nobody has contradicted that the air circulated respectively: through the curtains, on the sides, by the seams etc ie my examples in photos).

While your measurements tend to make you think you would win ~ 37% and that if we added shutters (+ 10%), or could reach a total savings of 47% ... It would be wonderful! This simple calculation shows that it is not in the order of things that it is possible to achieve (replacement of windows: argon and PVC frame = 15% only on the overall construction ...). Basically, the truth is that you improve comfort in part of the interior volume, my losses as a whole ... change very little.

But this is just the opinion of a poor bewildered BA techno.

[Christophe]

But this is just the opinion of a poor bewildered BA techno.

a) lowering the U by 0.5 is already not bad! Especially compared to the price of a curtain compared to a change of chassis! It is equivalent to going from a chassis of K = 1.6 to 1.1!

b) radiation (impression of a cold wall), a subjective notion (depending on the humidity of the air in the home) is not taken into account in this figure ... so I think we can double that figure. So improve the chassis K by 1 for a few hundred euros, well I think it's HUGE ...

Did you have curtains at home one day?

Again, I am not saying that it is a panacea for curtains and that it will transform an energy-consuming house into a thrifty house!

Only, they make it possible to improve comfort for a modest investment and the modesty side of the investment there is not much else ...

For shutters, a "good" shutter + air gap has a K of 5 !! R = 0.2!

Cf:
https://www.econologie.com/credit-d-impo ... -3600.html

Safety shutters

a) Insulating shutters characterized by an additional thermal resistance provided by theshutter-ventilated air gap assembly: R> 0,20 m² ° C / W.

For a single component with foam polyurethane thermal transmittance of 0.035, this corresponds to an insulation thickness of the component at least: 0,2 0.035 * = = 0.007 7 mm.

Nature of the closures (shutters, blinds) is also involved in reducing losses, especially at night.

So to lower the K by 0.5 is to increase the R by 2, it is 10 times more than what is requested by a "GOOD" PART !!!

ps: K = U = 1 / R

[Obamot]

This is if your curtains are closed permanently ... for a window with perfect insulation (no air stream passes). Which is rather doubtful in this case, 12 ° C at night, mebon ...

Then the first time you open your curtains in the morning, you mix the two volumes of air and your ratio collapses ... (also because the daytime period is much longer than the nighttime period) That's it the weak point of the curtains must take into account habits: day AND night ...

In addition, it must be understood that we estimate that the best curtains do not have an effect that exceeds 75% (necessarily there is air that is exchanged with the other volume of heated air, that cannot not be ... 100%). If we agree with that, we must have an hour-by-hour weighting. But Alsace (zone "I" at an altitude of 400 to 600m, or -19 ° C as the temperature to be taken into account and not -7 ° C as above ... which was only for illustrative purposes ...) your region is a "cold" region which explains the 12 ° C, it is obvious that the delta is not the same. So to see if you reach the 10% average, you would have to put it on a Gaussian curve and see what the standard deviation is ...

Now to combine the "curtains" effect with the "shutters" effect is a bit daring (see not possible) ... Indeed, you must take into account the fact (if we start from your hypothesis) that you would already have 10% , at best compared to curtains ... so the ratio is no longer the same. Do we agree that it is not cumulative by a simple addition?
Because if it is yes, that would mean that by putting up curtains and shutters we arrive with savings of 20% ... again it's too optimistic. If you already arrived at 10% in constant data (therefore theoretical) Curtains + shutters, again it would be wonderful

In reality, all thermographies show the opposite, there are very few differences ... alas!

[Christophe]

This is if your curtains are closed permanently ... for a window with perfect insulation (no air stream passes). Which is rather doubtful in this case, 12 ° C at night, it does not smell good ...

Thank you for your advice but there are no leaks on our chassis ...
Because a shutter you close it 24/24? Strange habits in Switzerland say so!

Come on I stop there, you start again / continue on the same tone (you shouldn't leave this subject definitively?) ... then yes you are right a curtain it is useless, we will burn our own like that at least they will bring something ...

Are you happy?

[Obamot]

Dslé, nothing to do. And obviously nothing personal either. The facts are stubborn: 25% during the day and 75% during the completely closed night period. And yes, on the north side in winter we basically leave everything closed and we live on the south side with us ... Anyway, I'm sure you see what should be weighted or not, so I edited my message to give you the temperature values ​​according to your region and altitude. If you were at another altitude I could give you the correct value and then it would be more obvious. @ +

[Christophe]

Hey again you speak without knowing and in this case it's frankly bad luck for you: we have no window on the north side ...

Hey yes there were already houses not too badly designed at the base in the 80s ... so when I see the CLIMATE DAUBES which are currently being done (heated supposedly "clean" with nuclear geothermal energy) ... gently smile ...

You know those barracks that go "well" in magazines (both TV and paper) that look like nested containers ... full of concrete, good thermal bridge, and large bay windows everywhere to have plenty of light ...

Obviously none of it has a curtain or shutters ... it would be too ugly!



Otherwise it's been a long time since I've been in Alsace ... but then again you think you know everything ... do a search our address is on the site ... come on ...

[Obamot]

... randomly I took Alsace:


Just to give an idea. There was really nothing wrong. I don't see why you see everything wrong. Good evening.


PS: same for the orientation of the house. Very happy for you (I said with us ...)

[Christophe]

You had a 1 in 2 chance ...

I take it badly because your tone incites him ... and I'm not the only one to think the same.

[Obamot]

Who should we take as an example?

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