Dehumidifiers

ventilation first
then
dehumidification

Why Count? Do you have a problem with perspiration?

Nic

I had a perspiration problem a few weeks ago Nic, when I found some mold on the outside of my record cabinet, near the floor. I then started to think of a few other things which have had a little bit of mold on them over the years and so I researched the subject on the net.

I've had three temp/humidity sensors placed around the house for 1 1/2 years and basically open windows if they read over 65%. If it's rainy weather (July-August every day) then it's pointless opening the window.

Two weeks ago, I bought a £200 Ebac dehumidifier. This initially worked pretty good, but was very noisy and kept freezing up making it inefficient. The manufacturer told me it was faulty and to take it back. I exchanged it for the next Ebac model up at £300. This lasted 2 mins before making a loud noise and broke. It was poorly built anyway. I took it back for a refund.

I have just bought a Japanese Mitsubishi model at £320. This is in a completely different league. It's built superbly, so quiet and sucks moisture out of the air effortlessly.

Ebac are British crap. The Japs really are great.

Did you know, humans produce 3 pints of humidity just breathing.

Count,

I can quite believe that, there are also some pretty frightening statistics about how much skin we shed over the course of a year, but that is another story.

We actually have an Ebac model (3 or 4 years old I think), which has just been put back into action for the winter.

They are made not far down the road from here, in a pretty deprived area. Although the build quality of the one I have has not been a problem the organisation is pretty chaotic. They kept chasing me for a payment on a service a few years ago which I had already paid, because their systems were up the spout.

Our house has traditional sash windows with very thin float glass so the condensation is bad in the winter. Although I have tried breathing less, I then remembered about Michael Hutchence and afew MP's and decided that a de-humidifier was a safer bet.

What do you suspect has caused the mould? The problem with more modern homes is that they are virtually hermetically sealed, draughts are actually good for ventilation, if not always comfort. Bob is spot on regarding ventilation.

Hope the problem is now cured.

Regards

Nic

Bad experience with dehumidifiers there! I've used 2 for 10 years and no problem. It is amazing how much water vapour humans produce though!
I must add that in my experience dehumidifiers do not stop mould forming. That happens when air doesn't circulate, which is why ventilation is more important. Let a few draughts in and see if it improves.

move to Spain.

Check to see if you have any very slow leaks in the water system any where in the house.

quote:

Originally posted by nicnaim:
The problem with more modern homes is that they are virtually hermetically sealed, draughts are actually good for ventilation, if not always comfort.

Yes but modern homes have "Better" DPC, wider cavitys/trays, better sound proofing/fire insulation and ventilation in the right places without causing discomfort. Older dwellings are not in the same league when it comes to warm/dry and comfort even though they are more artistic on the feature side of things.

Even the bricks, drainage, lintels, mortar, ties and oversites are much better, i could go on... but you get my drift.

regards, Steve

Steve,

Thanks for that, you may not be aware but I am actually a Building Surveyor by trade.

I'm afraid I do not share your enthusiasm for modern house building. My 1908 mid-terrace with 13" solid brick walls may not have the thermal qualities required of a new build under current Building Regs Part L, but you would never find me buying a new house.

Better sound proofing, you are having a laugh! I could go on, but I'm sure you get my drift.

Regards

Nic

Nic,

Everytime we do a re-furb on a pre war house in pompey it always ceases to amaze me/us how the things stay up! The footings are a brick on egde and that's it!
I reckon if you wanted to, you could if you were heavy enough, run through the walls.
The mortar is only sand and lime, which is always mostly damp. I would never hang a record deck up on these walls without first knocking it all down and starting again and this goes for most of them.
Saying that, the've stood the test of time, but they are damp cold smelly places when you start ripping things out, then it all comes to light, how they literally were thrown up abortion style!

regards, steve

Steve,

There have always been people who cut corners, whatever the era. Granted the foundations were a different construction, but if they have stood the test of time, they must have got something right. Although working with lime mortar is probably not your favourite, it does allow for some movement without cracking the bricks unlike portland cement. You would definitely struggle to run through my walls, when I had a new boiler fitted the plumbers were cursing how long it took them to get through the English bond.

Regards

Nic

quote:

Originally posted by bob mccluckie:
ventilation first
then
dehumidification

Absolutely. One floor of our rather old house is built into the embankment of the adjacent canal. Provided we keep the room ventilated with windows open a crack and the door ajar when not being used the dehumidifer is almost never called into play (it kicks in at about 50%) even in good solid Yorkshire weather. A very low level panel heater helps too, probably partly by moving the air.

Is your house old? Do you have fireplaces blocked up that would naturally vent rooms? Our surveyor made the point that an old house will always be slightly damp due to the more porous construction, however they are draughty for a reason! Fitting double glazing can make damp worse without thought adequate ventilation.

Bruce

Yes we have double glazing which does hermetically seal the humidity inside, but in the UK's humid climate, opening the windows on damp days (or nights which are always high humidity) will only draw humidity in the house and not out.

Showers, breathing/perspiration, cooking and washing all add pints into the air. To dry that out, the humidity outside would have to be less than inside. How often is the humidity outside less than 55%? Looking at weather site stats from yesterday, humidity ranged from 74-95% during 24hrs. If I'd had the windows open the humidity would have risen inside. I think the answer would be to ventilate on dry days and use the dehumidifier on wet days. I'm no expert, so any more views are very welcome.

Hi,

Bearing in mind, there is no point in running a dehumidifier unless the room is sealed, with all the windows shut. Another expensive option which does not solve the 'real' problem is to have a fan heater running constant with the windows ajar.

I would check to see all the air bricks are clear - even take a couple of bricks out ( where the damp is ) and see if the cavity is clear. Lift the floor boards up and see if the oversight is clear right the way through to the air bricks. I've been in houses Where cowboys have ripped down the old plaster and buried it under the floors.

It sounds like to me the building is already damp and the humidity has nowhere to go because it is already damp ( hence some of the above )

Try to avoid rapid heat change also and whatever you do do not use a gas fire, it will make things much worse.

regards, Steve