MHRV Filter - Oilly black substance?

GilltownJoe

Hi,

Noticed recently that the incoming air filter on my heat recovery ventilation unit has an oilly black substance on the incoming side of the filter, similar to black oil, horrible stuff. It is only on the incoming side of the incoming filter.

Anyone got any ideas of where it might be coming from? First i thought someone nearby may have been burning wet fuel in their fire and it may be the smoke getting sucked in but this started during the summer when fires not in use.

Andrew_Doran

GilltownJoe wrote: »

Anyone got any ideas of where it might be coming from? First i thought someone nearby may have been burning wet fuel in their fire and it may be the smoke getting sucked in but this started during the summer when fires not in use.

If you live in an (sub)urban area or near a busy road I would suggest diesel cars, vans and lorries.

I see the same and it's the only thing I can think of.

http://news.bbc.co.uk/2/shared/bsp/hi/pdfs/07_08_12_fo4_dieselpollution.pdf

KELLY: We‟ve walked somewhat blindly into a situation where
we have more than one in two private cars now being purchased as being a diesel vehicle.

O‟HALLORAN: As opposed to about one in ten twelve years ago?

...

KELLY: Diesel vehicles are particularly bad emitters of
particles, so if you‟re comparing a diesel car to a petrol car, then you can do a rough guess
that the diesel will be producing ten to twenty times more particles than the equivalent petrol
car. It really is quite an enormous problem, I mean, it‟s now recognised that air pollution is
the second biggest public health challenge we have after smoking, so this is a major cost
driver to our NHS system.

fclauson

It can also be tyre rubber - again depending how close you are to a major road

near the M25 in London this has been a noticeable problem with any white surfaces

GilltownJoe

Both good thoughts but I live in countryside with minimal traffic, also, only started over last few months. Thanks though

fclauson

So I live rurally as well and I have noticed
a) during the harrowing season (spring) that the fine clay of Wexford gets blow up and is picked up by fly filter in the HRV
b) durign the summer a much finer "muck" (pollen probably) makes its way to the HRV filter itself

the rest of the dark stuff I am assuming is jut the detritus of life

When did you last change the filters - 6months seems to be a good time frame

GilltownJoe

Pollen could be the answer and then as you saw other stuff sticks to it.

Cheers

I change filters every 3 months or so. I bought big roll of filter media from industrial supplier as buying filters individually was very expensive