Ventilation VMC heat loss, a question that grieves me

[I Citro]

.... That's how we came to the conclusion, to enslave the vmc, to a hygrometer, or something like that.
I also propose to plug all windows vents, and check the humidity level of the house.
I find it incredible to build a house (ten years ago), with interior insulation.

A VMC has a low flow rate, this is why it must operate continuously.
If you block all the air inlets, how are you going to renew the air?
In 2012, the majority of new homes were insulated from the inside.

Your findings are relevant, but your solution is not functional.

[the middle]

With its wood cassette, 15kw, when it is minus 13 outside, in the morning in his house, there are 12 degrees!
There is a famous problem ..
The little crisp info, the original heating is electric..

If you block all the air inlets, how are you going to renew the air? Confused Question

I count on the various and inevitable leaks of the house. (But to be checked with a hygrometer)

[Christophe]

In 2012, the majority of new homes were insulated from the inside.

Is that so? Source? Here it is indeed external insulation that I see on construction sites ...

Otherwise for info, the VMC, long mandatory has not been in the new for a few years ...

Insulating with breathable / breathable (ytong) or / and natural materials (wood wool, hemp, lime ...) makes it possible to do without CMV without problem ...

[fam]

Hello as usual. it deviates.

In answer to the first question yes it eats energy and hot air itself "very" greedy in energy; the basic idea is to remove excess moisture from the air, because it is more difficult to heat humid air than dry.
It is therefore a gain / loss ratio, initiated by France of all-electric. For me the idea of ​​an engine that runs 24 hours a day is an aberration.

If we accept that the variation of the humidity rate comes from the frequentation of the inhabitants and not from the building, the problem is already posed differently. If, on the other hand, the humidity comes from the building, this problem must be dealt with first.

From the moment when it is the inhabitants who generate humidity alone (breath, perspiration, showers, cooking) a hydro regulator seems desirable to me if we want to keep a CMV.

I'm not talking about dual flow vmc (this has advantages and costs)

Assuming habitat not affected by structural moisture disorders et very well insulated in the air, and that we remove the vmc we are faced with 2 questions.

How to ensure sufficient air renewal for the inhabitants?
How to avoid an excess of humidity by the occupation (the windows of the room fogged up after a crazy night for 2, or more prosaically a shower all alone?)

Question 1: Ancestral answer: open the windows wide for 5 minutes (no more), 2X per day.
Question 2: ditto more for wc, bathroom and kitchen, extraction during or just after use with and / or hydro regulation, the outlet valves being isolated.
(PS: irony of the airtightness tests of RT 2012, the tests are done by plugging the VMC outputs!
MDR, no comment ..)

In my isolated site project where each Watt counts and the CMV is not in the favorites, I think of different solutions:

1) Adopt the principle of protected volume in overpressure (renewal of cold air from below, hot air being denser) (In my case there is an uninhabited floor)
2) condensation of moist air at the top, with recovery from below
3) Direct evacuation with insulated openings (ex range hood)

cordially

[chatelot16]

when it is very cold the outside air becomes very dry when you get inside, so the necessary VMC flow decreases

the hydroreglable current system decreases the flow by more or less blocking the circuit ... but leaves the engine running continuously

and given the weakness of the humidity sensors that directly activate the air shutter ... and the impossibility of controlling the operation, I have doubts about the efficiency

another problem when there is long duct in a cold attic the air sucked arrives cooled to the group of VMC therefore seems more humid and unnecessarily increases the flow

solution to invent, electronic CMV regulator measuring the humidity in the right place in the accommodation, and modulating the operating time of the vmc ... and in addition feasnt turn in priority at the hottest hour of the day

another problem: a dwelling is not waterproof like a submarine: when there is wind there is inevitably leaks which make a certain flow: beyond a certain wind the VMC is useless: a good system measuring the should notice this and shut down the CMV completely as long as the wind does the job

CO2 measurement is another criterion for regulating VMC

[I Citro]

(PS: irony of the airtightness tests of RT 2012, the tests are done by plugging the VMC outputs!
MDR, no comment ..)

It is quite logical.
And if there is a VMC DF, the stale air outlet AND the fresh air inlet must be blocked.
In this way, the tightness of the building AND the tightness of the VMC network are checked.

[I Citro]

In 2012, the majority of new homes were insulated from the inside.

Is that so? Source? Here it is indeed external insulation that I see on construction sites ...

You are lucky to live in a country that is 30 years ahead of the question ...
Cellular concrete, which is an exterior insulation, has been used for decades in your home while it remains marginal in France.

My niece has just taken delivery of her standard brick house (like mine in the 70s), isolated from the inside like all the other houses in the subdivision under construction ...
The screed is not insulated and the roof receives 200mm of glass wool ...
The only concession to modernity, it requested, as an option, a VMC DF with poor performance which is already leaking (evacuation of condensates) ...

RT2012 will not be mandatory until January 1 ... 2013.
Despite my advice, she got a M - - - - E, which I dare not imagine the dizzying depreciation ...

[Christophe]

(PS: irony of the airtightness tests of RT 2012, the tests are done by plugging the VMC outputs!
MDR, no comment ..)

It is quite logical.
And if there is a VMC DF, the stale air outlet AND the fresh air inlet must be blocked.
In this way, the tightness of the building AND the tightness of the VMC network are checked.

Yes logical for the "procedure" (if not of course that it would not be good) but in fine, in use, it does not correspond to anything ! We test the air tightness to ventilate better (electrically) later ... Not very logical!

This "clogged" VMC infiltrometry test is therefore not far from pipo ... or useless ...

I'm always looking for an annual primary energy balance sheet for a VMC DF ... to compare to an insulation without VMC with breathable materials ...

If it talks to someone?

[fam]

Well seen !

There is a priori that with VMC the balance sheet on gain / loss is favorable.

Well I do not believe it, it strikes my logic.

It seems to be on the same level as the Coo waterfall!
http://fr.wikipedia.org/wiki/Centrale_d ... rois-Ponts

Long live nuclear!

[fafane77]

thank you all but i don't see my solution and i have a hard time heating my barrack. the air inlets on the roller shutter boxes constantly spit cold air out at me.
as for my firm home of good brand I have to turn on at 16 p.m. to be hot at 21 p.m. almost when I go to bed I'm exhausted from this barrack I even think about selling it, there is thermal discomfort .
So, according to you, just as my environment told me, the insulation from the outside will not solve anything at all ??
I'm fed up .....................