MHRV plastic ducting

Home4Life

I have installed MHRV with plastic ducting.

Does anyone have any concerns about the health implications of air supply through these plastic ducts.
Is there any evidence to suggest that there are health risks associated with it?

YourAverageJoe

As opposed to what other type of ducting?

My worry with HRV is how do you clean the ducting (possible mould/bacteria growth) after a few years of warm moist air travelling through it?

sinnerboy

http://www.boards.ie/vbulletin/showthread.php?t=2055385732&highlight=hrv+fire

gizmo555

sinnerboy wrote: »

http://www.boards.ie/vbulletin/showthread.php?t=2055385732&highlight=hrv+fire

This is a very helpful and informative thread which should be read by anyone considering HRV.

I'm looking at a retrofit installation and the prospective suppliers use plastic ducting. While they do fit firestopping intumescent collars on the ducting just behind the vents as standard, they had apparently never been asked about fitting the springloaded vents with fusible links, nor about interlinking the fan and the smoke alarms.

Once I asked them they agreed it would be no problem to do and add little to the overall cost - the springloaded vents add about 3% to the total.

The thread has also made me think about the four recessed light fittings in my kitchen ceiling and I may replace those with fire rated units.

Home4Life

great replies already and thanks for those.

However, I wasnt clear enough in my original post.

I have heard some talk about a cancer risk assocaited with air supply to the house through plastic ducting.

Is there any evidence or basis to this?
I ahve installed MHRV already on a retrofit of an old house,

Thanks,
H4L

gizmo555

Home4Life wrote: »

I have heard some talk about a cancer risk assocaited with air supply to the house through plastic ducting.

I'd have thought the risk, if there is one, is more than offset by the ventilation system clearing out, for example, the products of offgassing from paints, carpets, MDF, etc.

CJhaughey

YourAverageJoe wrote: »

As opposed to what other type of ducting?

My worry with HRV is how do you clean the ducting (possible mould/bacteria growth) after a few years of warm moist air travelling through it?

I have Spiral wrap galvanised ducting.
The air that passes through the ductwork is usually not moist as it gives up moisture in the heat exchange process.
It may be moist from the bathroom but that is the extract not the feed.

sydthebeat

Home4Life wrote: »

great replies already and thanks for those.

However, I wasnt clear enough in my original post.

I have heard some talk about a cancer risk assocaited with air supply to the house through plastic ducting.

Is there any evidence or basis to this?
I ahve installed MHRV already on a retrofit of an old house,

Thanks,
H4L

i have never heard of a cancer risk associated with heat revovery ventilation...

where did you hear it and what proof did the person have?? is this pub talk?

people need to remember that the extraction system in these units are sealed.. there is no physical mixing of fresh and stale air. Therefore any toxins being extracted are exhausted to the open air....

Home4Life

It is most likely pub talk.
I think the "urban myth" risk that people associate with it,
is the mixing of air in a plastic pipe, that it is the plastic that
is infecting the air and making it potentially "dangerous".
I dont believe in it myself, but just wanted to know if anyone else
had heard any foundation for it.

sinnerboy

Clean your filter every 3 months and inspect and if necessary clean the fan unit too

At least one a year remove all outlets / inlets and check for dust there

Straight smooth runs of ducts will resist dust settling . Bends kinks and changes in directions may cause dust to settle