Condensation/Mould Solutions - PIV

noitsnotme

WIAWSNB said:

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.

It creates a slight positive pressure which is what pushes out all the stale air through all the orifices.  The airflow coming in through the vent is faster than the airflow that is escaping, therefore a slight positive pressure.  Look it up. Or are you saying this is just sales patter?!

I don’t think anyone claimed it was magic, I certainly didn’t.  Far better than all our windows put together though 👍

WIAWSNB

noitsnotme said:

WIAWSNB said:

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.

It creates a slight positive pressure which is what pushes out all the stale air through all the orifices.  The airflow coming in through the vent is faster than the airflow that is escaping, therefore a slight positive pressure.  Look it up. Or are you saying this is just sales patter?!

I don’t think anyone claimed it was magic, I certainly didn’t.  Far better than all our windows put together though 👍

You are absolutely right; the PIV fan does have to create a slight imbalance in pressure - a positive one - in order to create the air flow. 

What I was remarking on was, "the windows stay closed virtually all the time during winter - this helps to retain a better positive pressure in the house." 

I'm not sure how this 'helps'. 

To take it to its logical conclusion, if your windows were so awesome that they were actually airtight, along with the rest of your house, then the PIV would just not work. You'd have all the 'retaining of positive pressure' you could want. But to no effect. 

It's a bit like a hose full of water being driven by a tap. If you close the far end, the flow stops. The resulting increase - retaining - of pressure inside the hose does not make the hose work better, it'll only threaten a burst. Like if you fully sealed your house, your skull would collapse inwards. 

(I'm a bit pished - forgive me...)

It isn't magic - it is just a controlled draught.

Albermarle

 Like if you fully sealed your house, your skull would collapse inwards. 

Probably some other bits would collapse first !

bjorn_toby_wilde

I think one point that’s being skipped over here is that it’s not so easy leaving windows open in a bungalow for security reasons. That’s why PIV could be more useful in this circumstance.

noitsnotme

bjorn_toby_wilde said:

I think one point that’s being skipped over here is that it’s not so easy leaving windows open in a bungalow for security reasons. That’s why PIV could be more useful in this circumstance.

I mentioned above my wife would never allow downstairs windows open overnight.  And we obviously wouldn’t leave them open when the house was empty, so there often wasn’t time to vent them adequately before everyone left for work/school.  Before the PIV, most of our downstairs windows also suffered badly from condensation.  

WIAWSNB

bjorn_toby_wilde said:

I think one point that’s being skipped over here is that it’s not so easy leaving windows open in a bungalow for security reasons. That’s why PIV could be more useful in this circumstance.

Windows have a locking vent setting. 

Mine's a (converted) bungie, and one opener on each of the downstairs bedroom windows is on vent. 

bjorn_toby_wilde

WIAWSNB said:

bjorn_toby_wilde said:

I think one point that’s being skipped over here is that it’s not so easy leaving windows open in a bungalow for security reasons. That’s why PIV could be more useful in this circumstance.

Windows have a locking vent setting. 

They do, but they never strike me as very secure because they make it easier for someone  to lever open the window.

Maybe that’s just me but I only ever leave the upstairs windows at the front locked like that. A thief would need to be perched on a ladder in full view to get in.

WIAWSNB

bjorn_toby_wilde said:

They do, but they never strike me as very secure because they make it easier for someone  to lever open the window.
Maybe that’s just me but I only ever leave the upstairs windows at the front locked like that. A thief would need to be perched on a ladder in full view to get in.

That's fair enough, and undoubtedly true that a window on vent is more vulnerable.

I should have added, we have nothing worth stealing. 

bjorn_toby_wilde

WIAWSNB said:

bjorn_toby_wilde said:

They do, but they never strike me as very secure because they make it easier for someone  to lever open the window.
Maybe that’s just me but I only ever leave the upstairs windows at the front locked like that. A thief would need to be perched on a ladder in full view to get in.

That's fair enough, and undoubtedly true that a window on vent is more vulnerable.

I should have added, we have nothing worth stealing. 

Neither do we. We have two grown up kids…..they’ve had it all. 😁

McKnze21

I think I will bite the bullet and order one today.

I think I have decided on the Nuaire Drimaster Heat HCS PIV as I am not so sure I require the sensors and/or switches. However, given my attic space measured at 9 degrees last night, I reckon the heater function will be a good addition.

This morning, all windows were covered in condensation so without putting heating and/or opening windows, I believe a PIV is really my only option and seems like the above is a good model to go for? Temperature/Hygrometers for each room were averaging 18 degrees and 70% RH.

Any further advice then please feel free to add!