Double Glazing Condensation

what percentage of the overall house moisture may come from the kitchen/cooking/washing machine ? with increased open plan layouts that must be exacerbated,
most neighbours never open kitchen window a jar when cooking, in addition to hob fan.

I supppose a humidity 'meter' might help diagnose issues too.
 
jpaul said:
what percentage of the overall house moisture may come from the kitchen/cooking/washing machine ? with increased open plan layouts that must be exacerbated,
most neighbours never open kitchen window a jar when cooking, in addition to hob fan.

I supppose a humidity 'meter' might help diagnose issues too.
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I imagine washing machines is very little, and when cooking should use an extractor fan (building regs part F recommends 10 air changes per hour I believe).
Problems will come from things like condensing tumble dryers with no air to escape, and recirculating kitchen extractor fans (rather than ducted externally)
 
The Craig said:
I imagine washing machines is very little, and when cooking should use an extractor fan (building regs part F recommends 10 air changes per hour I believe).
Problems will come from things like condensing tumble dryers with no air to escape, and recirculating kitchen extractor fans (rather than ducted externally)
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That came in in 2006 so unless he has a new kitchen it wont need to meet that regulation. Also 10 changes an hour is pathetic and IMO pointless, opening a window will work better.
 
Didn't realise old houses had such damp issues. Mine was built in circa 1997-1999 so it's fairly new.

I dry all my clothes indoors over radiators and on racks, etc. Even with all that extra moisture my humidity is in the 40's. I have 3 vents. 1 in the kitchen for the extractor. 1 in the main bathroom and 1 in the en-suite. the loft is also a "breathing loft" with vents around the sides.

I never open any windows or the vents on them. The only rooms that get condensation is the en-suite and main bathroom when your having a shower but that is normal and it clears up pretty quickly.

Modern home for the win then I guess. OP make sure your next home was built in the past 20 years.
 
jpaul said:
what percentage of the overall house moisture may come from the kitchen/cooking/washing machine ? with increased open plan layouts that must be exacerbated,
most neighbours never open kitchen window a jar when cooking, in addition to hob fan.

I supppose a humidity 'meter' might help diagnose issues too.
Click to expand...
Open plan doesn't really have much effect. It would probably spread the moisture around a larger area rather than concentrate it in one room. The humans in the house are the problem with all that breathing and sweating that they do.

jamief said:
Thank you - interesting read. Our house was built about 1925 and either has no cavities, or they are incredibly small, so no CW insulation. These PIV units - look interesting, do you typically have one per house? I'll also look into taping the window - it would at least rule out the leaky window as being the issue (or not).
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A PIV unit is usually situated in the loft and will serve the whole house. The ducting coming from it is quite large so you would situate the diffuser on the landing somewhere.

Honestly I swear by them. I fitted a lot of them at work and decided to install one in my old house and it took care of the condensation problems I was having there. Now that I have moved I will be installing another as the house constantly feels stuffy.

By squeezing out the damp air and replacing it with clean dry air it helps with allergies as well.
 
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TallPaul1878 said:
A PIV unit is usually situated in the loft and will serve the whole house. The ducting coming from it is quite large so you would situate the diffuser on the landing somewhere.

Honestly I swear by them. I fitted a lot of them at work and decided to install one in my old house and it took care of the condensation problems I was having there. Now that I have moved I will be installing another as the house constantly feels stuffy.

By squeezing out the damp air and replacing it with clean dry air it helps with allergies as well.
Click to expand...

What sort of filters do they have, something similar to an A/c unit?
 
TallPaul1878 said:
http://www.envirovent.com/specifier/products/positive-input-ventilation/

Enviro-Vent have a lot more products, they're more expensive but are arguably the market leaders in ventilation. I like the multi room input units because you can specifically target rooms for ventilation rather than just the landing area.
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Thanks, watched the University Nottingham PIV video on that site

it discussed pushing air from the loft into property to mix with existing air, but not any aspects of the evacutaion of that air - did I miss something ?
are the windows trickle vents meant to evacuate it ?
 
TallPaul1878 said:
Open plan doesn't really have much effect. It would probably spread the moisture around a larger area rather than concentrate it in one room. The humans in the house are the problem with all that breathing and sweating that they do.


A PIV unit is usually situated in the loft and will serve the whole house. The ducting coming from it is quite large so you would situate the diffuser on the landing somewhere.

Honestly I swear by them. I fitted a lot of them at work and decided to install one in my old house and it took care of the condensation problems I was having there. Now that I have moved I will be installing another as the house constantly feels stuffy.

By squeezing out the damp air and replacing it with clean dry air it helps with allergies as well.
Click to expand...

Where does the moisture from the air go and to me a PIV system is just a fan in the loft blowing air into the house. Am I missing something?
 
bloodiedathame said:
It was taking all the warm moist air and chucking it up into the loft, where it would just condense on the roof lining. It moved the problem away from the windows and into the loft, ruining loads of stuff in the process.
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How did you have it blowing air INTO the loft?? :confused:
 
No cloud formations then? :)

I thought the idea was that the moist air gets pushed out of the house from the loft pushing fresh air in. It's an interesting system. Something I'll do some more research on.
 
Six6siX said:
How did you have it blowing air INTO the loft?? :confused:
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The idea was that it would draw hot moist air into the loft, then use a pump/heat exchange to put fresh air back into the house through vents. In reality it just didn't work.

In the new house we keep the windows cracked open, use a tumble drier and keep the door closed after bath/shower. If we don't do these things we get loads of condensation.
 
Six6siX said:
How did you have it blowing air INTO the loft?? :confused:
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Depending what the actual units is doing, if its drawing air from outside into the loft then dehumidifying it, that water has to go somewhere. I assumed they would have an exhaust tube similar to an AC unit
(which reduces the airs ability to store moisture when its cooled and hence dehumidifies)

Edit, crossed with bloodied, in that case that seems a bit daft, most lofts have ventilation but they aren't designed to be actively having moisture added to them!
 
bloodiedathame said:
PIV system made it rain in the loft in our old house.
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I had a similar thing except it was when I used the gas fire for a weekend :o. It was a cold winter weekend and for some reason i turned on the gas fire instead of CH. It wasn't so bad as it was only a day or two before i spotted it but longer term would have cause a fair bit of damage. Gas fire only exists for looks now and i used CH to heat the house :p

I later calculated it out and with the max gas flow it puts out about half a litre of water into the air per hour... :mad:
 
bloodiedathame said:
The idea was that it would draw hot moist air into the loft, then use a pump/heat exchange to put fresh air back into the house through vents. In reality it just didn't work.
Click to expand...

So you had a pumping moist air from the house into the loft and back out via a heat exchange process of some sort? What did you do with the condensate? Was it a closed loop/unit or did it just vent into the loft space?

In any case, I don't think that's the same sort of PIV as nuaire etc which wouldn't have that sort of issue would it?

What you describe sounds more a heat recovery type whole house ventilation system to me.
 
Six6siX said:
So you had a pumping moist air from the house into the loft and back out via a heat exchange process of some sort? What did you do with the condensate? Was it a closed loop/unit or did it just vent into the loft space?

In any case, I don't think that's the same sort of PIV as nuaire etc which wouldn't have that sort of issue would it?

What you describe sounds more a heat recovery type whole house ventilation system to me.
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I'm not sure what happened with the condensate, there was no tray to empty etc. We did notice that the vents that went into the upstairs room had been blocked by the insulation in the loft which made no sense at all.

In the house we bought next we had heat exchange units in the upstairs rooms, it was ex-rental so it made sense that they were in there but were a total eye-sore and seeing as we felt pretty clued up to damp issues and how to avoid them, we ripped them out and sold them on ebay. :D
 
bloodiedathame said:
I'm not sure what happened with the condensate, there was no tray to empty etc. We did notice that the vents that went into the upstairs room had been blocked by the insulation in the loft which made no sense at all.

In the house we bought next we had heat exchange units in the upstairs rooms, it was ex-rental so it made sense that they were in there but were a total eye-sore and seeing as we felt pretty clued up to damp issues and how to avoid them, we ripped them out and sold them on ebay. :D
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Sounds like they were installed by a moron. I regularly have to do repair jobs on them. The industry is tightening up on regulations, installers MUST be qualified now for the installation to be covered by the NHBC.

When it goes wrong it can be a disaster. With MVHR units it is taking warm damp air, expelling it to atmosphere and drawing fresh air in, the heat exchange uses the warmth of the damp air to warm the fresh air. Condensation will form inside the unit and this is drained through a one way valve. If the extract ducting to atmosphere is situated above the MVHR unit then that will also need a condensation trap to prevent water from running back down into the unit.

PIV units add dry air to the home, this squeezes damp air out of the house, for it to be penetrating the loft space is bizarre and I've never experienced that in all my years of doing this.

If MVHR and PIV units are installed correctly, are commissioned correctly AND are maintained correctly then they are fantastic.

Funnily enough I've been doing a repair job on an MVHR unit today. This is due to some moron loft insulator stomping all over the drainage pipe and snapping it out of the MVHR unit. This has created leaks in the house and I've been getting some smarmy comments from the site manager. Perculiar that the 3 properties it has happened in are all next to each other, have all been insulated by the same guy and have all had the pipe work broken off.
 
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