Positive input ventilation - does anyone have this?

danlightbulb said:
Is that just because of the heat they generate?

There is one place a log burner could go but it would be right next to the TV and would require a through the wall flue.
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Immensely helps. They draw a lot of the air in the house and in turn the moisture in the air goes up the chimney!
 
We have one that came with the house. I only tend to run them over the winter months because of having windows open in the summer. Think it idles around 35-40W, humidity is pretty stable around 55% in our house, it's only the bathrooms that jump high from baths/showers - which is when it ramps up to about 200W to exhaust the air.

I don't notice it any colder in the winter months, I know it has a heat recovery system which I think uses the heat from the house to warm the air, but at 35-40W it definitely isn't heating it up.

Ours is a vent-axia, it has a boost control in the kitchen to ramp up the speed if needed but otherwise it should run automatically and adjust speed based on humidity levels.
 
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Nathan said:
Immensely helps. They draw a lot of the air in the house and in turn the moisture in the air goes up the chimney!
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This is a good point. When the house was built it would have had two open chimneys with fireplaces certainly downstairs but possibly also upstairs. Both chimneys have now been removed in this house. These would have drawn any winter moisture out of the house when they were being used and that's not an option any more.
 
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Best thing we ever did was get a Nuaire Drimaster, we used to have mould...now we don't(the kitchen was black when we bought the place). Initially you will get a loft smell but I don't even notice it now.

I was worried about the drop in temperature by bringing in fresh air but its not an issue and I think the general consensus is that its much easier to heat drier air than humid air.
 
roboamigo said:
1920s solid wall house here. Black mold behind wardrobes, condensation on windows so bad we rolled up towels on the windowledges to catch it!

Fitted a Nuaire Drimaster PIV and it solved literally all of this within 2 days of being installed. Have it set to 3 in the summer and 5-6 this time of year, and it is fantastic. We have it at the top of the stairs. Plus side is it helps dry clothes on the landing as the air is always moving.

Theres a slight hum if you listen out for it, and if you stand directly under you can feel a breeze.

Otherwise I would not be without it. Dont bother with dehumidifiers or anything else imo., this will do the trick.
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This was exactly our previous situation and resolution with a Nuaire PIV installed in the loft on the 1st floor landing.
 
PIV is good and can treat the symptoms of high humidity by forcing ventilation to take place.

Ideally it’s it’s better to buy a system with heat recovery over a PIV. A PIV effectively forces fresh air into the house and pushes out the air in the house out any cracks or vents.

A unit with heat recovery (MVHR system) exchanges the air and uses the air it’s sucking out to warm the air it’s pumping in.

A heat recovery system will be more expensive to buy but you’ll save on heating costs as the PIV will push out the warm air in your house and you’ll have to heat it again.
 
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Mvhr are significantly more effort to plumb in if you're doing it right though as you want bathrooms/kitchens to be your extract points which isn't easy to do when retrofitting.
 
SoliD said:
Unlikely to happen with PIV alone but thats mainly because you'll be blowing in 70% humidity air with the UK's typical weather system. You'd need something like MVHR and/or aircon to get down to that level.
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Thats not correct, 70% RH at a typical 6c outside temps is 33% RH when heated up to 18c. This is the whole point of PIV and why it helps people with condensation/humidity. I don't have PIV but I have seen the effect from general leakage as I run a dehumidifier 24/7 on my bottom floor to curb off RH down to 60% (usually its 80% due to various factors such as a bit colder than the rest of the house and also its underground). Usually it'll want a 5L tank emptying every few days but since its been so cold recently the air coming in the house via the front door, leaks, vents etc has been keeping it below 60% and i've not emptied it for a over a week now and its still practically empty. Its used 0.12kWh in the past 24 hours so basically the dehumidifier isn't doing anything because RH is self managing with air exchange from daily activities.

Obviously this is separate from active issues that are introducing damp (such as leaky gutters spraying walls, bridging of inner/outer bricks transfer moisture, low insulation, damp proof course not working properly etc) These items need investigating and fixing first before thinking about dehumidifying or PIV as you are then just treating a symptom, not the problem.
 
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Not only the above, there are also the ‘lifestyle’ factors of humidity. People, animals, fish tanks, drying clothing indoors, showers/baths etc etc.
 
gingergundog said:
Best thing we ever did was get a Nuaire Drimaster, we used to have mould...now we don't(the kitchen was black when we bought the place). Initially you will get a loft smell but I don't even notice it now.

I was worried about the drop in temperature by bringing in fresh air but its not an issue and I think the general consensus is that its much easier to heat drier air than humid air.
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Same here, we had the standard nuaire and it solved condensation overnight. Now upgraded to the nuaire heat which keeps a constant temperature running through. We've only just last week switch the gas heating on.
 
Maccapacca said:
Same here, we had the standard nuaire and it solved condensation overnight. Now upgraded to the nuaire heat which keeps a constant temperature running through. We've only just last week switch the gas heating on.
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It was a nice surprise how good they actually are, and quiet. Very easy to fit too, if comfortable wiring in a socket.
 
Have a Drimaster (non-heated, but the link version) on order, as we have condensaton/mold issues in the winter, and it might be affecting my wife.
 
What are these things like in the cold of winter? A normal loft is about as cold as the outside which would mean a stream of cold air entering the house.
 
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