Fwom:Mike )
Subject: De-humidifier question
"N. Thornton" wrote in message
om...

Oh I just wish our cellar/pantry did, even in summer. It is
buried into the
side of a wet hill and is permanently cold and damp so we've
blocked it off
and left unused for now. But would like to at least keep the
damp there
under some sort of control.

you cant ventilate it at all? WOuld help a lot if you could.

Oh continually. Must have several air changes a day though the
wall fan we
put in but that's why it's so cold in there :-(

You can see water actually trickling in though the wall on bad
days so it's
isn't really damp, more like running water :-) It used to be the
local
abattoir so I assume the cold was useful back then. The hooks for
hanging
carcases are still in the ceiling with a drain in the middle of
the room
indirectly feeding into the water supply to the local village.

Oh I see If its that bad I'd be wanting to check the floor
joists
above for rot,

Did that a while back. They were rotten :-(

Yeah, not surprised. :/


Currently the end of the house is an open two storey unused space.
Need to
preserve it whilst we get the rest of the house restored, then
thinking of
building a two storey self contained metal structure (including
stairs, etc)
within this space so that damp can be drained away around the
outside.

Metal doesnt like damp at all. Concrete would be much cheaper and
tolerates damp. Why metal?


and I'd get one of the bigger model dehumidifiers that
can extract more per day. Their quoted extraction rates are,
predictably, under somewhat unrealistic optimistic conditions.

We tried one of the compressor ones a while back and took it back as
it did
nothing. We now understand this was because the lowest working
temperature
of these appears to be higher than this area reaches on the hottest
summer
day. The ones mentioned earlier in this post claim to work down to 5
deg C
which is more realistic.

Compressor models will work down close to freezing point, as long as
they have a defrost on timer function. If they lack that, the cold
element will freeze solid at low working temps, and stop working. I
suspect that may be the problem. Or else possibly it froze up so
quickly that the daily defrost cycle just wasnt adequate - boosting
airflow rate would fix that, with a big fat external fan stuck on the
air intake. Looking at the cooling coil after its been running a bit
will tell you: if its icing, increase the airflow some more.

The extract rate will fall with falling temp for all types,
inevitably, as the air just doesnt hold much moisture at low temps.

BTW lime makes a workable desiccant, so you could test the rotor
technology with a box a fan and a bag of lime, see what sort of
extraction you get.


Sounds like a better approach would be to dig down beside the house
outside and put a barrier in, but that doesnt come cheap, and would
need a struc eng to check on how it could be done. Money tends to
rule
of course.

And the local council might have something to say about me removing
one of
their unnumbered roads

Fussy buggers arent they?

It might be possible to do it by removing a brick, scraping a space
out on the other side 18" wide, or however much you can, filling space
with gravel, and replacing said brick. And repeating all over the
wall. And while youre doing it, you might be able to paint the other
side of the wall with something tarry - not perfectly, but enough to
make a huge difference.

Inserting concrete in there would also help, on the other side of the
wall, 3:1 crete is pretty much impervious.


Have you spoken with the period property people?

Had a long conversation with some of the real experts on there two
years ago
(Chris Turner, GreenMan, etc) and have been working through them
since then.


I'm wondering if
gravel plus drain might even do you some good - impossible to know
without enough details though.

That's what Chris suggested and has been done where HM's highway
doesn't get
in the way. Definitely helped but you wouldn't believe how bad it
was when
we started. At least it no longer smells damp.


It almost sounds as if your cellar is below the water table!

My whole house is below the water table !! We are on the side of a
typical
Peak District hill - i.e. saturated. Currently our field has
standing water
on it everywhere. The sheep are asking for wellington boots :-)

Ha. Well, have you installed weep holes? Weep holes would desaturate
the ground on the other side of the wall to some extent. Since you
dont really want the water running in, drill weep hole and epoxy pipe
into it, run pipes to drainage.

Sounds like youve got a very difficult case there.

I'm guessing also youve not replaced the wall mortar? In an old house
the lime will all be thoroughly porous, in a powdery state by now.
Cutting it out and getting 3:1 cement in there would fix that. As
you'll know from the PP folk this would not usually be considered the
right thing to do, but in this case it sounds like just whats needed.
Why 3:1? Waterproof. The downside is the potential for brick cracking
if the house should move/subside, but it sounds like a good risk swap
in this case.

I imagnie a 4" interior concrete block wall would be the way to go,
tied to the existing wall, after thorough approaches to reducing
damp/wet. Using SS ties of course.

One thought does occur: I just wonder if ventilation could possibly be
making things worse, if the cellar is colder than outdoor temp,
venting will result in condensation and make it wetter. Venting only
helps if indoor temp outdoor.


I really hope this house was very very cheap, cos it sounds a badun.


NT