"Tim Lamb" wrote in message
news
In message , Andrew Gabriel
writes
In article ,
Tim Lamb writes:
Following the prolonged cold Winter, my wife is considering fitting air
extractors to her rented flat. (mould/condensation issues).

The obvious priority placing is in the bathroom with part P
consequences. One possibility is the low voltage offering from Kair
which appears to have provision for humidity stat operation.

The flat was originally heated by warm air ducts from a central off peak
store so there is also an opportunity for a centrally located
extractor/dehumidifier.

Does anyone have insight to the benefits/drawbacks etc?

Nowhere near enough info to diagnose the problem, which is necessary
before any remedy can be suggested.

:-)

First engage your advisor!

What sort of heating is there now?

Conventional full gas CH

Does the place feel warm, or is the heating ineffective?

Depends on how the tenants set the rad. stats but the system is amply
sized.

What moisture sources are there? Cooking, baths/showers, clothes drying,
...?

Cooking, baths/showers. Hopefully not clothes drying as there is a
condensing washer/drier.

When does the condensation/damp appear?

Particularly after a let this Winter.

Where does the condensation/damp appear?

On upper surfaces of North and shaded exterior walls. Manly bathroom and
bedroom.

Any idea what thermal insulation is installed?

11" cavity wall only. A tentative enquiry to BG bounced as insulation
could only be grant aided if *all* the flats in the block were done.

Are there any extractors, ventilators, etc.

No extractors. Double glazing has trickle vents. Kitchen has double air
brick but buried behind cupboards. Cooker hood is re-circ type.

Has it always been like this? If not, what happened to cause the change?

We thought the CH had solved the problem which had been noticeable with
the old air duct/ storage system. However a long, cold Winter coupled with
a family and children.....

More ventilation and more heat input but you can't stand guard over
tenants.
We were arranging a simple bathroom extractor (timed on exit if possible)
and realised the added expense of part P. One step further to a heat
recovery, low voltage extractor. But are there any *gotchers*?

Because large parts of the old ducting system are still there, a
centralised system might be possible but issues such as noise, cost of
running a dehumidifier, disposal of condensate, pressure balancing etc.
are a bit mind numbing.

I think we should pursue the cavity insulation aspect despite British Gas.
I believe the building is based on a concrete frame so the cavities might
be stopped at each floor.

My parents own the middle floor of a 3 flats. They managed to get cavity
wall insulation done recently. It just needs the people above and below to
have theirs done at the same time. Not everyone paid the same price as my
parents did not qualify for a full discount as it is not their place of
residence. I believe that they paid £150.

A humidistat fan in the bathroom may be better than a timed fan. And what
silly prices have you been quoted for a fan installing?

Cheers

Adam