Positive Input Ventilation advice

[John Brown]

I went for the one without the heater in the grounds that:
A) It's much cheaper
B) Electricity is about 3 times dearer than gas for heating.
C) I'm a cheapskate.

 

[Ollie78]

I have a Vent axia one with heater ( not sure the heater does a great deal, hard to say ) It is very effective.
It did take a few weeks to dry out the house but once it's done that I would say it has reduced our condensation on windows and cold spots by 90%. On super cold days we still get a bit, but before it was pooling on the window boards.
Tried an expensive dehumidifier first and there is no comparison, the piv is superior in our case, and cheaper to run.

Got mine at Fastlec, I upgraded my filters to the HEPA ones (you won't believe how black they are after a year) . This stopped the random itchiness my daughter was complaining of almost immediately. Maybe because it stopped mould maybe the air filtration, not sure.

Ollie

 

[artie]

I'm wondering where does the extra air imported by the

Positive Input Ventilation advice​

go to?

 

[John Brown]

I'm wondering where does the extra air imported by the

Positive Input Ventilation advice​

go to?

If that's a serious question, then it doesn't go, it comes. Imported stuff comes, exported goes. It comes into the house and gently pushes out the humid air already present.
If it's not a serious question, then forget I replied.

 

[artie]

It was a serious question.

If fresh air comes in an equal amount must leave,

I was wondering does it just leave through leaky doors, windows etc or does anyone install vents so it could be directed to a certain area?

 

[John Brown]

It was a serious question.

If fresh air comes in an equal amount must leave,

I was wondering does it just leave through leaky doors, windows etc or does anyone install vents so it could be directed to a certain area?

Keyholes, trickle vents, letterboxes, gaps around doors and windows etc. In our house there are plenty of exit routes. No doubt you could add some venting if required, for us it most certainly isn't.
However, I'm not any sort of expert - just fitted one in my house, and have been blown away by the transformation.

 

[DeanN]

Ensures a constant change of air, so condensation has limited chance to form.

 

[Rodpr]

I guess if house is constantly at positive pressure with air being pushed out of nooks and crannies then cold draughts can’t push their way in through those same nooks and crannies. But are you driving out heated air and replacing with cold air from loft space?

 

[John Brown]

I guess if house is constantly at positive pressure with air being pushed out of nooks and crannies then cold draughts can’t push their way in through those same nooks and crannies. But are you driving out heated air and replacing with cold air from loft space?

Yes. But for us, at any rate, it's preferable to having black mould on the window frames.

 

[user 35906]

We fitted one about 6 months ago to a house my daughter rents out, the house is a 1930s semi, all double glazed and has insulation in the loft and walls but with the first tenants who have been in for over 6 years, seemed to be suffering with condensation/mould especially around windows and some walls (possibly due to them drying clothes on radiators?) When they moved out we fitted a Nuaire unit after reading good reports and after a recommendation from an old friend who has had one fitted years. Early days yet as the house was occupied just after it was fitted but I do remember people saying it also blew the warm air layer down from the ceiling level by the heater so helped circulate wasted heat.
The main problem we had was the house has a hipped roof with little height over the landing ceiling and getting the clearances from where we could actually fit the outlet from the walls and smoke detector. (the clearance from near-by walls determines the max speed the fan can be set to) but 2 baffles were supplied that can be fitted to avoid blowing onto walls that are too close.
Hopefully it will help reduce the amount of redecorating that has been required in the past.