advice on condensation/ getting a dehumidifier?

[Toby]

We have a lot of condensation on doors and windows and some spots of mould starting. I think it may be because we don't put the heating on much. I was thinking of getting a dehumidifier to extract the moisture from the air. Can anyone give any insight into these in terms of brands and volume for a 4 bed house. Don't want one that's too noisey. Would you leave it plugged in all the time? Thanks

 

[onq]

Hi Toby - not a lot to go on here.

Age of property, method of construction, level of insulation, ventilation method etc are all factors to consider as outlined below.

- Ventilation of spaces and insterstitial spaces - spaces within the building's construction)
- The level of relative humidity - the amount of water vapour in the air
- Temperature of the building envelope - how warm at the surfaces the moist air will reach
- Thermal bridging - specific locations where the building envelope is conducting heat strongly.

This is what one considers when dealing with condensation arising from within the building.

To this can be added

- Leaking service pipes
- Water ingress from outside
- Groundwater levels
- Flooding.

These are instances of water coming from outside the house.

Until these facts have been assessed I would advise that you don't spend money on a dehumidifier, as other issues may be causing the condensation.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

 

[Toby]

Thanks ONQ

Its a standard 1950s semi detached. No flooding. Moisture probably from shower, cooking and drying clothes indoors as well as occasional use of vaporiser for kids when they are sick.

Who would I contact to assess the cause? It hasn't been such a problem before and only since weather got cold so I thought it was as simple as the heating not being on as much this year. Would improving insulation help or make the problem worse.

Thank you

 

[onq]

Hi Toby - what's a "vapouriser" and how often do you use it?

I take it - and correct me if I'm wrong - that it ejects moisture into the air to ease breathing difficulties - much like a steam tent treatment for Croup?
If so and if the excess moisture isn't vented it will definitely contribute to a build up of vapour in the air.

Improving the insulation may help, as would making the perimeter surface warmer but such matters can be complex.
More heat in the air results in more moisture being absorbed.
More ventilation can cool the air, precipitating moisture out.

A competent architect or a consulting mechanical and electrical engineer should be enough.
I used both on one job to sort out problems with an uninsulated internal duct and external corner detail.

I's say your problem is an uninsulated house filled with moist air and you will need to address insulation and ventilation.
The windows may be still single glazing and/or the double glazing seal has failed.
The window frames and door frames may not be thermally broken.
They may be north facing and over large for the room.

These could all be factors.


ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

 

[Toby]

A competent architect or a consulting mechanical and electrical engineer should be enough.
I used both on one job to sort out problems with an uninsulated internal duct and external corner detail.

ONQ

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.

Thank you. I'm not quite sure how to go about finding a consultant who is an expert in the area of insulation etc. Our house is hard to heat in general. Im in Dublin. Would you have any suggestions on how I could find someone to advise us on insulation/heating/condensation etc please. thanks

 

[Leo]

Thank you. I'm not quite sure how to go about finding a consultant who is an expert in the area of insulation etc. Our house is hard to heat in general. Im in Dublin. Would you have any suggestions on how I could find someone to advise us on insulation/heating/condensation etc please. thanks

You could try posting in the Recommend tradesmen and suppliers forum.

 

[Toby]

Thanks,I have posted in the recommendations forum.

Would getting a Building Energy Rating be a good place to start identifying problems with the house?

 

[Shane007]

Would getting a Building Energy Rating be a good place to start identifying problems with the house?

That would depend on the background of the BER Assessor. Many of them were churned out by a certain company in 3 days. A friend of mine completed the course and got certified and he is an airline pilot with no experience in construction whatsoever. He was told that if he could read maps, he could be a BER Assessor and they took €2,500 off him! SEAI took a further €1,000 off him to register him with them.