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positive pressure ventilation

(25 Posts)

Anyone used this?

We've got a 1960's detached, upstairsdownstairs house. No cavity wall, double glazing.

Some condensation at the windows in the winter, but mould developing behind curtains, furniture and in wardrobes. Not dreadful, we painted the bedroom eight years ago and the mould is limited to invisible places.

Also have two wheezy kids.

Someone suggested PPV as a way of improving ventilation and, hopefully, reducing hospital admissions.

I've never heard of it - anyone got any opinions?

Also, we've got plans in for an extension - should it be done before, or after that? Loft space will be unchanged in the old part of the house, just tacking an extension on the back.


PigletJohn Thu 24-May-12 12:33:59

It can work, but is very much a last resort.

The three much more effective things to do (in order of importance)

1) don't drape wet washing around the house or over radiators

2) Use an extractor fan during and after every bath or shower, with the bathroom door and window shut, until all the water has gone (including wet shower tray and towels) or you can open windows now the summer is here instead

3) ventilate the house by using trickle vents all the time, or opening bedroom windows every day between getting up and making the beds.

BTW if you have a 1960's house, I bet it has cavity walls, not solid. You can get subsidised or free insulation from the company that supplies your gas or electricity.

Thanks, Piglet - that's great.

It is a cavity wall house, not currently insulated. But, that's getting done over the summer along with the extension.

I do usually have wet washing hanging in the boys' room in the winter. On an airer, not on the radiators - but, the house looks like Widow Twankey's most of the time...

And I OPEN the bathroom door to let the condensation out whilst running hte extractor fan. This makes no sense at all, will do your way now! excited am I about getting a utility room in the extension? All my dreams are coming true!

Thanks for the advice.

unadulterateddad Sat 26-May-12 23:19:31

Go and buy a decent dehumidifier - for example , costs about 5p per hour when on and will keep a house free of condensation.

As a plus it dries washing really fast. One of these keept me sane in a very damp house smile

Dries washing really fast?


Thanks for that suggestion, will do!

Staceroo Wed 21-Nov-12 21:47:23


My husband works for a manufacturer of these positive input ventilation systems. As a result we had one fitted in our bungelow in March 2011. We have had no condensation or mould since and do not have any additional extract fans as our kitchen and bathroom are both off our hallway.

The fan, which is mounted in the loft, replaces all the dirty, damp air in the house once every couple of hours with fresh, filtered air from outside. This solves the root cause of condensation and mould which is excess moisture in the air, normally from everyday activities like washing, cooking and drying washing - all essentials especially with a new arrival!

There is also plenty of evidence to support claims that asthma sufferers and people with other respiratory-related problems really benefit from living with these systems as they filter out 95% of airborne pollutants that are otherwise present in indoor air.

As an added benefit over the last two summers we have not slept with windows open as the fan provides fresh, cooler air through the hot, stuffy summer nights!

My husband suggests going direct to the manufacturer if you are interested rather than third parties such as damp-proofers. Check out EnviroVent, based in Harrogate. They will carry out free-of-charge surveys and can then make some reccomendations.

Hope that helps smile

Sharonrb Sat 01-Feb-14 07:37:48

If I go direct to the manufacturer for the unit then what type of company do I ask to fit it?

gouldydl Sun 23-Feb-14 20:08:43

Hi, I know this an old thread, but does the house cool down with the positive input ventilation system?

alejamruc Tue 14-Feb-17 16:41:39

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Trethew Tue 14-Feb-17 20:16:25

Please can you explain simply how it works, and where you put it?

alejamruc Tue 14-Feb-17 20:48:15

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alejamruc Tue 14-Feb-17 20:52:25

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Trethew Tue 14-Feb-17 21:04:03

Thanks alejam. I've read the blurb on the internet but still have some doubts. I'm thinking of it for a 1966 council house. Despite being an award winning development at the time, the whole estate suffers with condensation. Some houses have had cavity wall insulation installed but there has been a high failure rate (but that's another story).

My main questions are
1. Is it expensive or noisy to run?
2. Doesn't it make a cold draught coming from the landing?
3. Can it really stir up the air in the furthest corners downstairs, wouldn't it have already found a way out?

alejamruc Tue 14-Feb-17 22:07:21

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cherrytree63 Wed 15-Feb-17 08:33:42

Alej...can you control the fan remotely? Do you need to change the speed in different seasons?

alejamruc Wed 15-Feb-17 08:49:14

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Trethew Wed 15-Feb-17 09:54:01

Thanks Alejam, that's all really helpful

TrippyMcTrapFace Wed 15-Feb-17 15:30:21

PigletJohn's advice is spot on. BTW he's a long term poster here, whereas one poster on this thread hasn't made any other contribtutions to MN apart from resurrecting zombie threads to share with us all about a certain ventilation system. MOTWYW.

alejamruc Wed 15-Feb-17 16:00:44

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Trethew Wed 15-Feb-17 20:01:32

I for one am extremely appreciative of both Alejam's and Piglet's advice. Both conscientious and intelligent contributors who have taken time and made the effort to share their knowledge and experience

Trethew Wed 15-Feb-17 20:04:52

Please don't drive them away by being cynical

TrippyMcTrapFace Wed 15-Feb-17 21:02:50

Trethew I have no intention of driving anyone away. Just seems odd that someone has joined MN purely to resurrect zombie threads in order to talk about this amazing device.

HopeClearwater Thu 16-Feb-17 20:11:17

Trethew I've not long installed this. I paid a fair bit for it and have nothing to do with any company which supplies or fits it. I'm pleased so far: it's not particularly noisy (it would really annoy me if it was) and it's already brought the humidity levels in the house down considerably. I also had some more powerful extractors put in too. Because the air is dryer, the house doesn't feel cooler. Doesn't seem harder to heat. Yes you can feel a bit of a draught sometimes on the stairs but it doesn't bother me. I can't say anything about the long term effects as I haven't had it long enough yet. Hope this helps.

Trethew Thu 16-Feb-17 20:52:31

Thanks hope. Do you leave your internal doors open circulfor better aid circulation?

HopeClearwater Fri 17-Feb-17 12:53:13

Not deliberately but the kids don't know how to shut them grin

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