Preventing condensation

[Jcloughie]

Just did a little more research. Units start around £300 and should be an easy fit for most homes. Lots of good reports, but one with an unexpected twist. They have a house in Brittany, Installed one to keep the house drier. But when it got cold it made the area around the outlet colder which attracted the very thing they wanted rid of. But that was an unoccupied property. Also you can get them with a 500 watt heater which comes on at very ow temps to prevent that.

John

 

[Beachball]

Our bungalow is 55 years old and every double glazing window we get condensation, and on the ceiling it either mold , black spots not sure what to do whether to paint it with damp seal paint any suggestions i would appreciate it
That is why i was thinking of the PIV

 

[Jcloughie]

Our bungalow is 55 years old and every double glazing window we get condensation, and on the ceiling it either mold , black spots not sure what to do whether to paint it with damp seal paint any suggestions i would appreciate it
That is why i was thinking of the PIV

If I were you I would seriously look into them. Otherwise, stop cooking, washing, heating and showering. Oh, and breathing.

John

 

[ProfJohnL]

Well we had someone give us a quote it one thousand pounds so i don"t know whether to get a second opinion for the job ..

Definitely get more than one quote. having read:

https://www.property-care.org/wp-content/uploads/2017/04/Best-Practice-Guidance_PIV-System_v1.pdf

Some systems can be quite simple and therefore reasonable to install, but it all depends on what system is required and what special access requirements may be needed.

 

[Beehpee]

I’ve fitted a replacement cistern in our bathroom today, still inside a vanity unit but I’ve covered every bit of the outer skin with 150 mm insulation, set the water level to be a little lower than previously which gives a slightly lower area that is getting the cold water on it, every bit helps eh, I’m sure this will pretty well cure all of the previous condensation which as I said previously wasn’t loads, I’ll give it a few weeks and see if there is any improvement, I will be surprised if there is not a noticeable change.

BP

 

[otherclive]

I’ve fitted a replacement cistern in our bathroom today, still inside a vanity unit but I’ve covered every bit of the outer skin with 150 mm insulation, set the water level to be a little lower than previously which gives a slightly lower area that is getting the cold water on it, every bit helps eh, I’m sure this will pretty well cure all of the previous condensation which as I said previously wasn’t loads, I’ll give it a few weeks and see if there is any improvement, I will be surprised if there is not a noticeable change.

BP

6 inch of insulation! What did you use?

 

[Beehpee]

ROFLMAO I meant 15 mm, wouldn’t be room to get it in the vanity unit

 

[Beachball]

Definitely get more than one quote. having read:

https://www.property-care.org/wp-content/uploads/2017/04/Best-Practice-Guidance_PIV-System_v1.pdf

Some systems can be quite simple and therefore reasonable to install, but it all depends on what system is required and what special access requirements may be needed.

Hi Prof JohnL I would agree with get more quotes one is not enough thanks

 

[Beachball]

If I were you I would seriously look into them. Otherwise, stop cooking, washing, heating and showering. Oh, and breathing.

John

Hi Jcloughie i like some of what you wrote back to me (Oh and breathing was that a Joke)

 

[Sam Vimes]

Just noticed this thread so a bit late to the discussion but it is a subject that interests me.

We were fortunate enough to be able to design and build our own house and for a number of reasons specified a Mechanical Ventilation and Heat Recovery Unit (MVHR). In respect of this conversation we have no condensation anywhere in the house at any time of the year. Humidity control is one aspect and as I write the outside humidity is at 91% while inside its 51%. It's mostly around the 50% mark all year round. Temperature is pretty much uniform throughout the house.

Other benefit is that it's over 90% efficient in reclaiming the warm outgoing air.

PIVs may offer a solution to condensation in some instances but care is needed in implementing the installation. They are easier to install compared to MVHR systems especially if trying to retrofit.

As you know the PIV draws air typically from the loft into the house and needs to circulate to those places where condensation is a problem. Since it relies on expelling or rather pushing the air out through 'leaks' either through poor build standards ( e.g. poor sealing around doors and windows etc) or designed features (trickle vents), it will take the path of least resistance and may not circulate the air to where you really need it to go. In a house with low air permeability i.e well sealed, there may not be sufficient air 'gaps' for the air to escape and again circulation could be a problem.

And of course at this time of year it will be taking cold air from the loft and pushing out the warm air in your house.

Another option for condensation control or specifically humidity control are Humidity Sensing Extractor fans. Even Amazon sell them ( well they sell just about everything) but I don't know how effective they are.

 

[Jcloughie]

Just noticed this thread so a bit late to the discussion but it is a subject that interests me.

We were fortunate enough to be able to design and build our own house and for a number of reasons specified a Mechanical Ventilation and Heat Recovery Unit (MVHR). In respect of this conversation we have no condensation anywhere in the house at any time of the year. Humidity control is one aspect and as I write the outside humidity is at 91% while inside its 51%. It's mostly around the 50% mark all year round. Temperature is pretty much uniform throughout the house.

Other benefit is that it's over 90% efficient in reclaiming the warm outgoing air.

PIVs may offer a solution to condensation in some instances but care is needed in implementing the installation. They are easier to install compared to MVHR systems especially if trying to retrofit.

As you know the PIV draws air typically from the loft into the house and needs to circulate to those places where condensation is a problem. Since it relies on expelling or rather pushing the air out through 'leaks' either through poor build standards ( e.g. poor sealing around doors and windows etc) or designed features (trickle vents), it will take the path of least resistance and may not circulate the air to where you really need it to go. In a house with low air permeability i.e well sealed, there may not be sufficient air 'gaps' for the air to escape and again circulation could be a problem.

And of course at this time of year it will be taking cold air from the loft and pushing out the warm air in your house.

Another option for condensation control or specifically humidity control are Humidity Sensing Extractor fans. Even Amazon sell them ( well they sell just about everything) but I don't know how effective they are.

Great reply Sam. I think I am right in saying the MVHR systems would be considerable more expensive and require ducting through the property. They lend themselves to new build and ideally need to be considered in the design stage. But would be an ideal solution for sure.

Fully agree that the PIV idea could work, but could also fail for the reasons you mention.

I had forgotten about the humidity controlled fans. I was aware of them as I considered installing one in the airing cupboard after installing a radiator in there. But it was so difficult to duct to the outside, I gave it a miss.

John

 

[otherclive]

We have a humidity sensing 6 inch extractor fan in the kitchen. It is away from the cooker as there wasn’t sufficient space around the cooker, down pipes and boiler. It works very well in that environment. But when not cooking it is switched off.

 

[Beachball]

Now looking at the conclusion the PIV might not work will the humidity controlled fans help me.
Do i just put damp seal paint on would that be better and use the moveable humidifier .

 

[Sam Vimes]

Great reply Sam. I think I am right in saying the MVHR systems would be considerable more expensive and require ducting through the property. They lend themselves to new build and ideally need to be considered in the design stage. But would be an ideal solution for sure.

Fully agree that the PIV idea could work, but could also fail for the reasons you mention.

I had forgotten about the humidity controlled fans. I was aware of them as I considered installing one in the airing cupboard after installing a radiator in there. But it was so difficult to duct to the outside, I gave it a miss.

The unit cost and install cost of MVHR vs PIV would be condiserably different - MVHR more expensive. The MVHR does require ducting throughout the house and while retrofitting this to a single story building with loft e.g. bungalow, is possible, multi storey houses would prove more difficult. However, coupled with the install of an MVHR system is the need for controlling the air permeability i.e the airtightness. As you say easier to do at the build stage than later.

To just cure condensation problems retrofitting an MVHR in my opinion doesn't seem the best option due to cost and difficulty if at all possible. Of course we had other reasons than just condensation control for choosing such a system.

 

[Sam Vimes]

Now looking at the conclusion the PIV might not work will the humidity controlled fans help me.
Do i just put damp seal paint on would that be better and use the moveable humidifier .

Well it depends. If you can easily put a Humidity Controlled Extractor Fan in the areas you have problems it might be a solution for you. Still pushes warm air out though.

A moveable humidifier would equally work but maybe not as convenient if you have to move it around.

My daughter in NZ had an old house reminiscent of what we had here in the '60s although timber construction. Single glazed, zero insulation and damp in the winter. She found a portable humidifier in the second hand shop for NZ$10 and it made an incredible difference to the warmth and feel of the house.

 

[Beachball]

Well it depends. If you can easily put a Humidity Controlled Extractor Fan in the areas you have problems it might be a solution for you. Still pushes warm air out though.

A moveable humidifier would equally work but maybe not as convenient if you have to move it around.

My daughter in NZ had an old house reminiscent of what we had here in the '60s although timber construction. Single glazed, zero insulation and damp in the winter. She found a portable humidifier in the second hand shop for NZ$10 and it made an incredible difference to the warmth and feel of the house.

Hi Sam There are two rooms the kitchen ,bedroom and the hall way that suffers bad with condensation but if we can get a Humidity controlled extractor fan that could sort it we will get some quotes in for the job .

 

[otherclive]

Hi Sam There are two rooms the kitchen ,bedroom and the hall way that suffers bad with condensation but if we can get a Humidity controlled extractor fan that could sort it we will get some quotes in for the job .

It will send your heat straight out. We only use ours when mega cooking. We’ve had dehumidifiers ever since we lived by the Walkham in Devon and our white cottage turned green each winter. Still have an Ebac that my wife uses to dry washing that cannot be tumbled dried and if the ambient outside conditions aren’t suitable. The Ebac has a particulate and charcoal filter too.

 

[Kevin M]

Unity CV3

<p class="font_8">Low energy continuously running fan</p>

www.greenwood.co.uk

I’m a construction director for my sins.
PIV is great if designed correctly and ducted to the outside, still requires quality extract fans to the usual areas tho.
Your easiest solution (and one I’ve used with great success in my own home) is to use constant running fans, hopefully the link to the greenwood product works.
Easy to fit and set up, silent In use and in our house have cured the issues with condensation and mould growth.
In our main bathroom, my 2 20y/o children shower at least twice a day each and the fans boost when required and easily cope with the steam etc.

Kev

 

[Buckman]

As said ours seems to be a very simple plain fan arrangement that takes the moist air into the loft area. There is a small vent tube over the extractor fan which directs the air away from the fan area. It seems to work okay and it not cost a fortune.

 

[Jcloughie]

As said ours seems to be a very simple plain fan arrangement that takes the moist air into the loft area. There is a small vent tube over the extractor fan which directs the air away from the fan area. It seems to work okay and it not cost a fortune.

I refer you to the previous replies to this be myself and the prof. Extracting to the loft is really bad practice which will accelerate roof failure.

Could this also be why you are having difficulty heating your home?


John

 

[Buckman]

I refer you to the previous replies to this be myself and the prof. Extracting to the loft is really bad practice which will accelerate roof failure.
Could this also be why you are having difficulty heating your home?
John

We have resolved the heating issue and it is now nice and comfortable in the home for a change.
Our loft is quite large and taking into account only two of us plus animals I doubt if venting into the loft would be bad practice otherwise they would not have installed the unit there?
Bathroom as its own extractor that vents directly to the outside.

 

[ProfJohnL]

Now looking at the conclusion the PIV might not work will the humidity controlled fans help me.
Do i just put damp seal paint on would that be better and use the moveable humidifier .

The condensation you are experiencing is not coming through the wall of the cistern, so painting it with Damp seal will do nothing.

The condensation is the result of the air in your room being well laden with water vapour and warmer than the cold water entering your cistern. The cold water cools your cistern and the air in the room touching the cistern is also cooled.

As the air cools it passes its dew point and some of the water vapour its carrying is deposited as condensation onto the wall of the cistern. If you apply dampseal all it would do is to add a thin layer of paint which will make virtually no difference to the amount of condensation you get.

There are two ways to reduce the condensation, first and probably the most significant is to reduce the sources of high levels of moisture, and improving ventilation. Using a dehumidifier will drop the level of moisture, but its not resolving the underlying cause.

The second way to reduce condensation is to prevent the warm air from touching cold surfaces. i.e. improved insulation. - But this does not remove the underling cause.

 

[Jcloughie]

We have resolved the heating issue and it is now nice and comfortable in the home for a change.
Our loft is quite large and taking into account only two of us plus animals I doubt if venting into the loft would be bad practice otherwise they would not have installed the unit there?
Bathroom as its own extractor that vents directly to the outside.

Good luck with that.

John

 

[Beachball]

We have resolved the heating issue and it is now nice and comfortable in the home for a change.
Our loft is quite large and taking into account only two of us plus animals I doubt if venting into the loft would be bad practice otherwise they would not have installed the unit there?
Bathroom as its own extractor that vents directly to the outside.

Good luck and thanks for you input on this matter

 

[Beachball]

Unity CV3

<p class="font_8">Low energy continuously running fan</p>

www.greenwood.co.uk

I’m a construction director for my sins.
PIV is great if designed correctly and ducted to the outside, still requires quality extract fans to the usual areas tho.
Your easiest solution (and one I’ve used with great success in my own home) is to use constant running fans, hopefully the link to the greenwood product works.
Easy to fit and set up, silent In use and in our house have cured the issues with condensation and mould growth.
In our main bathroom, my 2 20y/o children shower at least twice a day each and the fans boost when required and easily cope with the steam etc.

Kev

Hi Kev i think we will get some quotes how this Greenwood product works and thanks for the information