VMC, what it stands for and why you install it

[mint]

Hello, everybody, and a special hello to those who know about houses.

What does VMC stand for?  I guess something with the word Ventilation in there somewhere?

Would you go to the expense of installing one if you didn't have a damp house?

I'm back to the property with the pond I was talking about.  I'm now wondering whether, because of the ground conditions, the house might suffer from inherent damp and that that is why they have installed a VMC.

All thoughts on this would be greatly appreciated.

[woolybanana]

You gotta be joking, I thought everyone knew that, Sweet. Anyway, I wont insult you by telling you.

[AnOther]

You did ask [;-)]

VMC

[pachapapa]

Not necessarily but maybe who knows.

http://www.leroymerlin.fr/mpng2-front/pre?zone=zonecatalogue&idEIPub=1100623228

[Gluestick]

Interestingly, Sweets, all new build French houses have VMC as standard: the concept being to provide ventilation but with heat exchanging to optimise the super-insulation and reduce humidity without having to suffer heat loss via opened windows and local ventilation in shower rooms, bathrooms and kitchens.

Total Environmental Conditioning and Management is the new Gold Standard.

 

[Gardengirl]

We have this in our 2 year old apartment, Sweet. There is a low chance of damp in it as there's a lot of solid rock around it, the town is on a hill and we have no high ground around the apartment block. It's very efficient - in fact in winter it's too efficient and the current seems to blow around us and is a bit loud when all is very quiet. Condensation following a shower goes within a couple of minutes, whereas in our UK bathroom it hangs around for quite a while, with the mirror unusable; this despite a system OH put in to extract hot air out via the roof.

[mint]

Anyone has any idea how much electricity this VMC thing uses?[+o(]

[AnOther]

It would be wrong to separate that out as the consumption will be offset by the other potential benefits. You need to consider the overall energy running cost of the property.

[Théière]

[quote user="sweet 17"]Anyone has any idea how much electricity this VMC thing uses?[+o(][/quote]

Roughly 35-40 watts. As Gluey says used with heat recovery vents they are pretty good.

[suein56]

[quote user="sweet 17"]Anyone has any idea how much electricity this VMC thing uses?[/quote]

The VMC in our almost-but-not-quite-15 year old house runs continuously at a very low level but seems to use about 150w an hour when we switch it on to full blast.

Sue

[mint]

I never cease to be amazed at how knowledgeable you lot are!

So, I suppose I could turn it off in the summer, when I shall be opening doors and windows anyway and turn it on in the winter.

[pachapapa]

Unlikely to consume more than 50 watts, so with 8760 hours in a year one gets  438 kWH per year at say 0.15 cents/kWH.,around €65 a year.

 

[Chancer]

As low as 11 watts on the low speed setting and as much as 60 watts on the high, mine is a hydroreglable and I think it is marvellous, i also have one in my UK pied à terre (converted garden shed) which would be very damp and mouldy otherwise as indeed it was.

I reckon mine cost me €30 per year which is significant at this time of budgetary restraint but having seen the appalling damp problems in nearly new house where the departed tenant had switched off the VMC it is a small price to pay.

They are also very good at getting rid of nasty niffs, I had a soupçon that I had a smelly drain problem in my bathroom, it was barely perceptible but once I switched off the VMC the smell was unsupportable, I had in fact taken out a truc from the shower siphon and the drain smells were coming up through it, in fact whilst the VMC was running it was drawing its air from this source and still barely smelt.

I would deffo recommend the hydroreglable ones, once correctly adjusted they will switch to the high speed as soon as you create humidity even from a handbasin however one fo mine has gone open circuit on the slow running circuit and the other one now turns so slow on the low seting as to be ineffective however it switches to high often enough.

As I have a flat roof in uninsulated tôle bac acier over my two most humid rooms and during the construction the humidity was dripping off it on hot mornings I have used the spare ports on the VMC to ventilate this space and to date it has worked very well.

[broy]

I've had several limestone therefore kinda breathable houses without

vmc and have never missed one. there have been extractor fans in the

shower rooms which deal well with the steam from showers and

"ventilation naturelle" in the kitchen to deal with the old CO. no

humidity problems and no interest in fitting all the ducting etc. maybe

shoe box bungalows need the extra ventilation.

[Théière]

All well and good but are there posters out there apart from Me and Johnross who actually have a humidity test meter, without one its all pretty anecdotal

[Jo]

My brother has one fitted in his older house and swears by it to reduce humidity.

[Chancer]

[quote user="Théière"]All well and good but are there posters out there apart from Me and Johnross who actually have a humidity test meter, without one its all pretty anecdotal[/quote]

No dont have a humidity meter, a noise meter yes even a damp meter if I want to get technical but the back wall of what is now my salon which is one metre below ground level was just a mass of black mould when I bought the place, anecdotal mould maybe but definitely uninhabitable and I didnt need my damp meter or even my eyes to tell me so the smell was that bad.

When the sodden plasterboard fell away from the wall millions of small billes of polystyrene swept in waves across the floor, they had used doublage and the damp and mould had degraded it.

Other than now using rails and placo with fibreglass on this submerged wall its only the anecdotal V.M.C. that is keeping the damp at bay, perhaps the heating has some effect but its not on all of the year whereas the rain and water table are fairly constant.

I am pretty sure that when I get myself away from this dump and rent out the flat that I am living in if the tenant behaves as per the norm and switches off the VMC I will very soon be accused of providing a logement indigne.

[Théière]

[:D][:D][:D]