Extractor fan or dehumidifier for bathroom?

If the tenant has requested the extractor you would hope they are intending to make use of it. I would fit it, then you can't be held liable for mould & mildew problems. Have you noticed the adverts from ambulance chasing solicitors around encouraging claims by tenants of damp properties to sue landlords for health issues!?Shocking ?

Also have you got sufficient insulation in the ceiling space/ exterior walls? Cold exterior walls are a big part of the mould problem in damp areas such as bathrooms. The water vapour hits a cold wall & instantly condenses into water before it has a chance to be evacuated by either the extractor fan or an open window/velux.

I go by experience. I've not had a complaint in 15 years!

Opening a window to reduce relitive humidity is pointless in the winter when the RH (relative humidity) outside is greater than the inside. RH inside should be between 45% - 60% therefore if the RH outside is 80% your just letting in more moisture...I would use an extractor or a simple humidistat sensor these fans are capable of turning themselves on and off depending on the relative humidity of your bathroom.

Reply to the comment left by "Kate Mellor" at "05/12/2016 - 14:28":

Kate, very well said and accurate. I think often the problem is as you say the "exterior walls" not having sufficient insulation. And I must say the other posting by Paul Green gave a very succinct, in depth analysis of what happens to cause the condensation - I know this is the problem in the property I rent, where an extractor has been advised to be fitted twice in the last three years for the bathroom and kitchen, plus of course I have no CH, so I'm almost in a constant swimming pool, regardless of windows being opened.

Is there any way of the site verifying some or all of what Jill Harding says about her situation?

Reply to the comment left by "Jay James" at "05/12/2016 - 17:42":

Hello Jay, my posting is genuine. I have in fact been in contact with Mark Alexander on and off site. I contacted him originally about another problem I'm having but extended it to incorporate the damp problems I've been experiencing for the last 5/6 years in all now. I'm only just getting heating installed in to a 2 bedroomed property - only one old 1970's circa economy7 heater, the other one I had packed up last year sometime. But of course don't take my word for it, but I'm sure Mark can verify I'm genuine.

To get back to the problem. Just fit a good extractor with a power rating to suit size of room, sorted!

OK. So having decided an extractor fan is the gift from God you have been waiting for to vent a bathroom as the idea of a tenant opening a window seems to be something akin to saying the 'f' word in a church, what are you going to do about ventilating the rest of a property? Fit extractors to every room? Lack of ventilation can bring problems into any room of the house whether it's a high moisture producing room or not. Still need the tenant to ventilate and circulate the air- and yes including in the winter when RH is high.

Who'd have thought that "to extract or not to extract" could be such an emotive topic!

I have a ground floor 1 bed flat with an extractor in the bathroom (no window) and in the kitchen (1 window) in a converted Edwardian building EPC rated E (5 flats in 1 block). I've just had the bedroom interior wall chemically damp proofed by injection £975 with a 20 year guarantee (paid for by the sinking fund) and re plastered & painted, However, the flat still had a lot of moisture in the air and mould would appear on fabrics and walls. So I purchased a condensing dehumidifier £190 Capable of removing 30 litres of water in a 5 litre tank. Suitable for a 3 bedroom house. It has done the trick, in 4 weeks & my tenants love it. I also bought then a desktop hydrometer £6 to Measure the RH (relative humidity) of indervidual rooms. The results. No more mould, no more smells. The flats feels and smells a lot healthy and they have just signed a new 12 month AST. (No tenancy finding fees for new tenants and no void period) My tenants also leave the central heating thermostat on 10 degrees Celsius ( as advised by me) This keeps the flat at a constants temperature and the walls retain the heat, in the winter months, so moisture can't settle on the walls and form mould, it also stops the water pipes from freezing in the winter.lastly I'm also going to install a Positive input ventalation system £307 for the unit plus £180 labour (my handymans going to fit it) with a heating element. This draws fresh air in from the outside, filters it then warms it to 7c at ceiling height and creates pressure in the flat forcing out stale, moist air through the fabric of the building. As the dehumidifier is portable I need a portable appliance test (PAT) yearly.