hi,
I have recently rennovated a 1940's house and now it is finished and got a tenant in it,we are starting to see condensation problems.
we have told the tenants to keep the house ventilated to wipe down any condensation they find.We all know that condensation is due to certain aspects of lifestyle,but upon asking a damp 'specialist',they told me of this kleen air system,which regulates and aids correct air distribution throughout the property.So many times these conversations end up as sales pitches,and at nearly a grand for one of these systems,I'm reluctant to go for it.But ,I don't know what else to suggest to them.Mould is starting to appear already,and with a young child on the way ,I certainly do not want bad conditions for them.
Anyone had experience of this type of system?
We have extractors in the kitchen and bathroom,although i can't guarantee that they are using them.....

AS you know your renovation will have added quite a lot of water to the home.

This water will take some time to dry out.

A wet wall will take twenty four hours to dry out one millimeter, from this you can see it may take some time to dry out.

Add to this the fact that a damp wall equals a cold wall and a cold wall attracts water vapour out of the air......and this means there is no improvement until the warm days of summer.

People add water vapour to their home by cooking washing breathing and sweating.

In the normal way a warm home will absorb the day to day water vapour and as long as the inside is kept warm, then the water vapour will enter the walls, ceilings etc; and make its way to the cold outside.

If however, they turn their heating off, or turn it down then, they are adding to the problem, as warm air holds more water vapour than cold air and that extra water vapour will appear either as running condensation on the windows or if the walls are colder/as cold then it will condense into the walls.

If the tenants can be persuaded to use the extractor fans (they may not like the cost of running them) and if they keep the bathroom and kitchen doors closed you may get a quick result.

Take heart, the summer is on its way, there is a lot of solar activity this year, so it may be a warm one, by the time next winter comes the place should be dry.

A note on forced ventilation.
Like extractor fans and heating, the tenants may not like the running cost.
In social housing where the tax payer picks up the bill, Councils try to install systems that cannot be controlled or turned off by the tennant. They still manage to circumvent the best intentions.
I would suggest you don't go down that road, it really is not worth spending the money.