Running an extractor fan for long periods (damp cellar)?

Wouldn't a humidistat-controlled version be more appropriate?

David

My cellar used to be dampish - not too bad in fact, as cellars go, but I wanted to put a washing machine, tumble dryer and freezer down there, and I didn't want things going rusty. I've got a small dehumidifier with a humidistat down there - one of these

I can't comment from experience on the extractor fan idea, although I can't see why it wouldn't work. I know from the bathroom versions that they are annoyingly noisy though, and unless you have a big house you may well be able to hear it in the bedroom. I can hear the fan in our downstairs loo in a bedroom two floors up and through two closed doors and some fairly solid victorian walls, but I could just be over- sensitive. However, if the fan is going to run all night as a long term measure you could probably run it much more slowly and quietly. The dehumidifier is only audible in the cellar itself.

Cheers!

Martin

On Mon, 30 Apr 2007 14:24:37 +0100, Adam Funk mused:

I'd have thought a dehumidifier would be a better choice.

Get a big 8" or 10" through-the-wall fan from Xpelair or VentAxia, designed for commercial use and priced accordingly. They should run 12 hours a day for years and be almost inaudible (except for when the backdraught shutter snaps shut).

The 4" £20 ones from the DIY shed will start squealing, or burn out and start a fire, or cause other distressing nastinesses.

Owain

Oh for a decent cellar. Why don't modern houses have them - then we could put the car in the garage. Cellars are ideal places for boilers - who thought that putting them is a small kitchen was a good idea??

I was about to post exactly the same response.

Backdraught shutters now seem to be operated by a thermal solenoid, so you don't get the loud bang of a magnetic solenoid anymore. OP probably doesn't need one with shutters in any case.

I picked up a very nice 6" Vent Axia from Cash Converters for £10, original box, full instructions, etc. It turned out to be about 10 years old, but had never been used (and was old enough to still have the magnetic solenoid shutters). It was intended for fitting in double glazing, but is now mounted in my garage wall, with a few minor modifications. This model is still sold (now with thermal solenoid) for over £100. It's certainly not inaudiable though -- it's a high throughput model.

I would have thought unobstructed air bricks back and front would give enough natural airflow. Maybe put extra ones in. I can't see that a fan is the way to go. Better to try and find out why it's damp. A rainwater drain might be blocked etc. If there are no obvious signs of water, check the general condition of floor and walls. The palm of the hand is as good as anything for detecting damp

Possibly --- I'll look into that.

...

I had a dehumidifier and was thinking about getting an automatic pump, because I was tired of emptying the tank every day and because it would fill up and shut off when I was away --- but the dehumidifier failed recently, so I'm looking for an easy, low-maintenance solution!

Is it possible to get a high-quality one with a small diameter (around

The front air brick is flush with the front of the house but recessed (when you look at it from inside the cellar) in a hole just bigger than two bricks --- so I want to mount the fan in a board, screw the board to the wall over the hole, and probably caulk around it.

Yes, they're slightly smaller fans from Xpelair or VA, but are more likely to be rated for 'domestic' cycles and might only last 20 years.

Still miles better than the s**te in the sheds.

Owain

|!I have a damp cellar with some ventilation (air bricks to the outside) |!but not enough, so I'm planning to mount an extractor fan in one of |!the air brick recesses, then run it as much of the time as necessary |!(controlled by a timer) to dry out the cellar.

Try to find out where the water comes from, almost certainly Ground Water, which means that you are drying not only the walls, but 50 ft of soil behind the wall, so it may never dry out completely, in the West Riding some cellars flood periodically depending on how wet or dry the year is. Some were dry between WWI and WWII when it was dry and damp after WWII when it was wetter

On Tue, 1 May 2007 12:30:24 +0100, Adam Funk mused:

You can get dehumidifiers with pumps built in, failing that though an automatic pump is an easy addition. You just want a condensate pump from a plumbers merchants.

In message , Lurch writes

Keeping in mind there are a few types. The solenoid type makes a loud rasp when it runs while other types like the peristaltic ones are pretty much silent.

Ventilation will bring the cellar down to exterior temp, and you'll then lose lotsa heat through the living area floors. IOW a fan will cost you much more than a dehumidifier to run.

A condensate pump will solve the tank emptying problem.

NT

Good point.

I'll reconsider getting a new dehumidifier and a pump, then.

Really, where? (I haven't seen any.)

When I was looking into this last time, the plumbing supplier I phoned (just before the old dehumidifier died) seemed a little surprised I thought he would have such a thing.

The whole concept is flawed in my view. You're simply sucking in air from outside through the air bricks. Sure, you'll create reassuringly large amounts of water but it won't make the cellar any drier.

My cellar is drier with a dehumidifier than it was before. I keep some tools down there, and they no longer develop the slight coating of rust that they used to. I take the point about it not being wholly efficient unless it operates in a sealed room. But the same logic applies to running the central heating - why bother, all the heat only ends up going through the roof in the end?