Condensation/Mould Solutions - PIV

McKnze21

WIAWSNB said:

Whose bedroom?

Does it need to be kept at a certain - highish - temp for any reason?

Ok, assuming not, this is something to try;

1) As soon as the bedroom is left unoccupied in t'morning, open all the window openers to at least its 'vent' setting, or a good inch or two if you can, if security isn't an issue. 

2) Turn the heating - CH radiator - off in that room - ie, down to, say, 1 or 2 tops. You don't want it coming on at all during the day, and only weakly overnight if it's really bludy freezing.

3) Shut the internal door to the bedroom, and walk away. 

4) Try and keep that damp corner as open as possible, with nothing sitting close to it - let air circulate.

5) Clean and kill that mould with mould killer/bleach.

6) Before bedtime, close the windows to 'vent', but leave them like this all night. Do NOT shut them fully. DON'T!

7) If you wish, by all means have the heating come on for a half-hour or so before bedtime just to make the room more welcoming. A cheap and easy way to do this is to use an oil-filled radiator on a digital timer - rad on Fb for £15, and digi timer £10 on eBay. That way you don't even have to think about it. Oh, and set it to come on a half hour before wake up too. This will cost pennies, and is the only time you need heat in that room.

8) Keep warm using a good duvet and an electric blanket - also set to come on with a timer. If you are a complete wuss, you can buy an all-nighter.

9) No need to be chilly in your bedroom, but don't do so by shutting the windows and turning up the CH. 

10) Do the above. Your condie issues will disappear. I'd even site the oil-filled close to that corner as that is clearly the coldest spot in the room, apart from the windows, obvs.

You are very welcome

Separately, fit a good quality extractor fan in the bathroom as Tacpot suggests. My bro just had new extractors fitted in his loos, and they were silly money - around £150 each? But, they are fully controllable (I think by BT and phone App), run pretty much constantly at next-to-no power consumption, are literally silent unless working in anger, and are humidity controlled. Oh, yes, and react - it's true - to odours. 

The installation of an extractor will be the biggest part of the cost, so it's worth forking out for a model that you can then ignore, but which will keep your rooms ventilated as needed. (I'll try and remember the model). 

Any room in the house you are not actually using, then ditto - crack the windows to 'vent' 24 hours, rad down to '1', and close the door. You will have cold rooms, but they will be dry.

This is my sons bedroom on the North West corner of the bungalow. We do however have it on the North East corner of the house also which is actually our bedroom. Condensation on our window also.

The en-suite shower for our room won't help and as for my sons bedroom, the bathroom is next door to his room so to go back to extractor fans, these will definitely be fitted in both wet rooms as again this will be contributing.

We don't want to have the heating on all the time due to cost and also due to fact we don't actually feel we need it on most the time as the temperature feels comfortable,. We also don't want to have to have windows open as this will pose a security risk with it being a bungalow.

This is what led us to look to alternative solutions and other than purchasing a couple dehumidifiers, 1x PIV was a suggestion put to us but I didn't know enough about them before hence why I am on here to look for advice and potentially recommendations on a particular model.

My detached bungalow is currently a 3 bedroom, however we plan to restore this back to a 4 bedroom as it was meant to be when first built. It is approx. 34 years old and gross internal floor area is approx. 129m2. It is timber frame with brick outer leaf, roughcast/pointed synthetic stone external finish. Walls approx. 300mm thick. There is good sub floor ventilation & good amount of loft insulation.

Thanks for all the advice and input so far, much appreciated!

WIAWSNB

McKnze21 said:

This is my sons bedroom on the North West corner of the bungalow. We do however have it on the North East corner of the house also which is actually our bedroom. Condensation on our window also. 
The en-suite shower for our room won't help and as for my sons bedroom, the bathroom is next door to his room so to go back to extractor fans, these will definitely be fitted in both wet rooms as again this will be contributing.
We don't want to have the heating on all the time due to cost and also due to fact we don't actually feel we need it on most the time as the temperature feels comfortable,. We also don't want to have to have windows open as this will pose a security risk with it being a bungalow.
This is what led us to look to alternative solutions and other than purchasing a couple dehumidifiers, 1x PIV was a suggestion put to us but I didn't know enough about them before hence why I am on here to look for advice and potentially recommendations on a particular model. 
My detached bungalow is currently a 3 bedroom, however we plan to restore this back to a 4 bedroom as it was meant to be when first built. It is approx. 34 years old and gross internal floor area is approx. 129m2. It is timber frame with brick outer leaf, roughcast/pointed synthetic stone external finish. Walls approx. 300mm thick. There is good sub floor ventilation & good amount of loft insulation.
Thanks for all the advice and input so far, much appreciated!

My son's bedroom is south-facing, and nicely warm during the day when the sun is out. But, if he shuts the windows tight during the night, he wakes to dripping windows and a damp patch in the corner just like yours. 

If he leaves them on vent, no such issue occurs. It really is that simple. (Ok, on particularly cold nights, some condie might still appear, but a fraction of what it would otherwise be. Simply wipe that up first thing, and leave the windows on vent.)

Pretty much everything I've read about PIV systems - mostly on this forum - has been, unironically, positive. Do they work? Seemingly, yes.

How do they work? By ventilating your house, just in a backwards manner. Ie, they do the same as cracking open your windows. 

Any drawbacks? Yes, they can create a chilled area where the grille is positioned, usually a central hallway or landing. Is that different to what a 'vent' window will do? No, except with the windows you also isolate these rooms by shutting their doors, so the heart of the house is still kept heated. 

Can you mitigate this PIV heat loss? Yes, by either having a model with a heat exchanger, or by adding a heater to it. Is this different to having a window on vent and a heater on? Not really. And that would be daft.

So, PIVs work. But so does opening your windows. One costs now't, the other many £undreds.

Any pros on PIV? I guess it's 'automatic' and works nicely behind the scenes.

McK, you obviously have nothing to lose by trying what I suggested - except a bit of heat... But that's also true of PIV. 

Please do try it. Ok, you cannot open your windows fully, but you can leave them on 'vent' - that is 95% of the job taken care of. 

Give it a bash. :-)

 

noitsnotme

Before the PIV I always found having windows slightly open made the rooms very cold in winter.  Plus the wife would never allow it downstairs overnight as she was too afraid of someone breaking in.  The coldness of the PIV seems to be very localised in just the landing.  You can’t even feel it at the bottom of the stairs which is almost directly below the vent (mainly because the air is directed sideways from the vent).

Im not sure how true it is but I did read that it might be cheaper to heat a house with a PIV because it takes less energy to heat air that contains less moisture.  Our gas consumption for heating hasn’t really changed since fitting the PIV.

WIAWSNB

noitsnotme said:

Before the PIV I always found having windows slightly open made the rooms very cold in winter.  Plus the wife would never allow it downstairs overnight as she was too afraid of someone breaking in.  The coldness of the PIV seems to be very localised in just the landing.  You can’t even feel it at the bottom of the stairs which is almost directly below the vent (mainly because the air is directed sideways from the vent).

Im not sure how true it is but I did read that it might be cheaper to heat a house with a PIV because it takes less energy to heat air that contains less moisture.  Our gas consumption for heating hasn’t really changed since fitting the PIV.

Fair points. 

A PIV is a gentle device, and that low level of incoming air will be shared throughout the whole house - every room will seep out some of its air - through windows, floors, whatever - from the PIV's air being 'forced' in through the doors.

I guess it achieves good results by providing a constant level of background ventilation, so excessive moisture just doesn't get a chance to build up.  

If folk, instead, shut their windows at night, and then fling them open during the day, that will also dry the room, but it'll have to shift a lot of accumulated damp in the walls too, for example; the rooms will effectively have repeated dry/wet cycles. And the ventilating, when it takes place, will be more literally in yer face, and a lot of folk won't like that - "It's cold!".

Also, natural ventilation via cracked-open windows will vary from day to day according to the weather - PIV makes this steady and constant. I have now't against PIV at all - most feedback is very good. 

The essential principle is the same, tho'; ventilate. And that can be done right away, and at zero cost.

shiraz99

Whilst PIVs are a good solution for some I think it might be a bit overkill for your situation. My advice would be to just get a decent dehumidifier. I'd recommend the Meaco range or if you can afford it an Ebac.

Also, don't forget to ventilate as much as you can. Condensation is usually a problem this time of year when the temperatures are not always cold enough for the heating to be on and there's a lot of moisture in the air, condensing on colder surfaces over night.

noitsnotme

WIAWSNB said:

noitsnotme said:

Before the PIV I always found having windows slightly open made the rooms very cold in winter.  Plus the wife would never allow it downstairs overnight as she was too afraid of someone breaking in.  The coldness of the PIV seems to be very localised in just the landing.  You can’t even feel it at the bottom of the stairs which is almost directly below the vent (mainly because the air is directed sideways from the vent).

Im not sure how true it is but I did read that it might be cheaper to heat a house with a PIV because it takes less energy to heat air that contains less moisture.  Our gas consumption for heating hasn’t really changed since fitting the PIV.

If folk, instead, shut their windows at night, and then fling them open during the day, that will also dry the room, but it'll have to shift a lot of accumulated damp in the walls too, for example; the rooms will effectively have repeated dry/wet cycles. And the ventilating, when it takes place, will be more literally in yer face, and a lot of folk won't like that - "It's cold!".

That's what we did before the PIV.  But then we were battling with completely soaked windows and pools of water on nearly every window sill in the mornings. Just opening the windows was not always enough to clear that without some help mopping up and letting in that much cold air around the whole house meant the heating needing to work harder to heat it back up again.

Mould around the windows was also a constant problem that needed regular cleaning.   The PIV has pretty much solved that too.  I might go over the window rubber seals with some mould cleaner once a year a now.

WIAWSNB

noitsnotme said:

WIAWSNB said:

noitsnotme said:

Before the PIV I always found having windows slightly open made the rooms very cold in winter.  Plus the wife would never allow it downstairs overnight as she was too afraid of someone breaking in.  The coldness of the PIV seems to be very localised in just the landing.  You can’t even feel it at the bottom of the stairs which is almost directly below the vent (mainly because the air is directed sideways from the vent).

Im not sure how true it is but I did read that it might be cheaper to heat a house with a PIV because it takes less energy to heat air that contains less moisture.  Our gas consumption for heating hasn’t really changed since fitting the PIV.

If folk, instead, shut their windows at night, and then fling them open during the day, that will also dry the room, but it'll have to shift a lot of accumulated damp in the walls too, for example; the rooms will effectively have repeated dry/wet cycles. And the ventilating, when it takes place, will be more literally in yer face, and a lot of folk won't like that - "It's cold!".

That's what we did before the PIV.  But then we were battling with completely soaked windows and pools of water on nearly every window sill in the mornings. Just opening the windows was not always enough to clear that without some help mopping up and letting in that much cold air around the whole house meant the heating needing to work harder to heat it back up again.

Mould around the windows was also a constant problem that needed regular cleaning.   The PIV has pretty much solved that too.  I might go over the window rubber seals with some mould cleaner once a year a now.

The point is, you shouldn't be heating the room unless it's needed - being occupied.
Yes, mop up with an absorbent cloth any visible condie on your windows first thing. Then vent the room via its windows, heating off in there, and shut the door. It'll be cold but dry.
No excuse to have heating on during the night, except at a low background level. No excuse to not vent the room overnight either - you should be snug under t'duvet.
Bottom line, if you are going to keep the windows closed, then you will almost certainly have to counter by having the room warm all night. Great, but it'll cost you.
A thing to bear in mind, tho', is, what that heat is doing is keeping your moisture suspended in the air. You'll still need to ventilate that increased level away, or it will find surfaces in your home to condie out on.

rob7475

We've had both PIV and dehumidifiers over the years. Both will probably solve your issue.

PIV may be a little more to buy initially. Filters will last a few years so not expensive in the grand scheme of things. They cost next to nothing to run - don't bother with the ones that have a heating element as it makes next to no difference to the air temperature. We bought one with a heating element but I turned it off after a couple of years and noticed no difference. It will cool down your house a bit as it's constantly drawing in cooler air from the outside. When I installed ours back in around 2014, gas prices were relatively low so the extra heating costs were worth it as the unit cured our condensation problems overnight. I ended up removing the unit in 2023 though due to the heating costs and the fact we were having a loft conversion so had nowhere to mount the main PIV fan.

We now use a dehumidifier which also acts as an air purifier. In AP mode, running costs are very low as it's just a fan with a filter. If we need to run it in dehumidifier mode, it does cost more to run but it's also blowing slightly warmed air out which may have a positive effect on overall heating costs.

MVHR is another option to look at as it gives you all the benefits and low running costs of PIV but none of the drawbacks like blowing cold air into your home. However, it's more complicated to retrofit so initial costs are higher. If you have loft space in your bungalow to run the ducting, it may be a good option though

noitsnotme

WIAWSNB said:

noitsnotme said:

WIAWSNB said:

noitsnotme said:

Before the PIV I always found having windows slightly open made the rooms very cold in winter.  Plus the wife would never allow it downstairs overnight as she was too afraid of someone breaking in.  The coldness of the PIV seems to be very localised in just the landing.  You can’t even feel it at the bottom of the stairs which is almost directly below the vent (mainly because the air is directed sideways from the vent).

Im not sure how true it is but I did read that it might be cheaper to heat a house with a PIV because it takes less energy to heat air that contains less moisture.  Our gas consumption for heating hasn’t really changed since fitting the PIV.

If folk, instead, shut their windows at night, and then fling them open during the day, that will also dry the room, but it'll have to shift a lot of accumulated damp in the walls too, for example; the rooms will effectively have repeated dry/wet cycles. And the ventilating, when it takes place, will be more literally in yer face, and a lot of folk won't like that - "It's cold!".

That's what we did before the PIV.  But then we were battling with completely soaked windows and pools of water on nearly every window sill in the mornings. Just opening the windows was not always enough to clear that without some help mopping up and letting in that much cold air around the whole house meant the heating needing to work harder to heat it back up again.

Mould around the windows was also a constant problem that needed regular cleaning.   The PIV has pretty much solved that too.  I might go over the window rubber seals with some mould cleaner once a year a now.

The point is, you shouldn't be heating the room unless it's needed - being occupied.

We don’t now and never did before the PIV.  I was describing what happened before the PIV, that  having windows opened during the day to try and dry up the rivers of condensation reduced the temperature in the house.  Then when the heating was needed later in the day, it had to heat the house from a colder starting point.

Now, with the PIV, the windows stay closed virtually all the time during winter - this helps to retain a better positive pressure in the house.  The house stays warmer even when the heating is not on because no heat is lost to open windows.  We still don’t have heating on overnight, just an hour or so in the morning and then a few hours in the evening.  We no longer have to mop up buckets of condensation and we no longer have a mold problem.  The heating doesn’t keep moisture suspended in the air, because there is virtually none compared to before the PIV.

It might not be for everybody, but for us the PIV has massively improved everything from before it was fitted.

WIAWSNB

noitsnotme said:

WIAWSNB said:

noitsnotme said:

WIAWSNB said:

noitsnotme said:

Before the PIV I always found having windows slightly open made the rooms very cold in winter.  Plus the wife would never allow it downstairs overnight as she was too afraid of someone breaking in.  The coldness of the PIV seems to be very localised in just the landing.  You can’t even feel it at the bottom of the stairs which is almost directly below the vent (mainly because the air is directed sideways from the vent).

Im not sure how true it is but I did read that it might be cheaper to heat a house with a PIV because it takes less energy to heat air that contains less moisture.  Our gas consumption for heating hasn’t really changed since fitting the PIV.

If folk, instead, shut their windows at night, and then fling them open during the day, that will also dry the room, but it'll have to shift a lot of accumulated damp in the walls too, for example; the rooms will effectively have repeated dry/wet cycles. And the ventilating, when it takes place, will be more literally in yer face, and a lot of folk won't like that - "It's cold!".

That's what we did before the PIV.  But then we were battling with completely soaked windows and pools of water on nearly every window sill in the mornings. Just opening the windows was not always enough to clear that without some help mopping up and letting in that much cold air around the whole house meant the heating needing to work harder to heat it back up again.

Mould around the windows was also a constant problem that needed regular cleaning.   The PIV has pretty much solved that too.  I might go over the window rubber seals with some mould cleaner once a year a now.

The point is, you shouldn't be heating the room unless it's needed - being occupied.

We don’t now and never did before the PIV.  I was describing what happened before the PIV, that  having windows opened during the day to try and dry up the rivers of condensation reduced the temperature in the house.  Then when the heating was needed later in the day, it had to heat the house from a colder starting point.

Now, with the PIV, the windows stay closed virtually all the time during winter - this helps to retain a better positive pressure in the house.  The house stays warmer even when the heating is not on because no heat is lost to open windows.  We still don’t have heating on overnight, just an hour or so in the morning and then a few hours in the evening.  We no longer have to mop up buckets of condensation and we no longer have a mold problem.  The heating doesn’t keep moisture suspended in the air, because there is virtually none compared to before the PIV.

It might not be for everybody, but for us the PIV has massively improved everything from before it was fitted.

Just to clarify, you don't 'retain a positive pressure in the house'. This does not work by 'pressurising' your house in any way.
It works by pumping in a gentle flow of air, which then escapes out every orifice it can find - past window seals, through floors, out keyholes, out under skirting boards, out via your bathroom and kitchen extractors, out around the wee gaps around your plumbing pipes, up the flue, etc. and it takes the moist air with it. It flushes your house. It ventilates it. So it clearly takes some heating with it.
If your house was airtight, it wouldn't work. 

But, I get it - it works. Almost all great reviews. But it isn't magic - it is an automated ventilating device - it keeps an air current flowing through your house. Like a clever window.