Having recently replaced the filters in my MVHR unit, I'm pondering whether it would be worth fitted additional filters in the actual ductwork to do the majority of the filtration.
Something like this:
http://www.justfans.co.uk/catalogues/PF150AL.pdf
With an additional filter (lets assume its a fairly coarse one) there would be some pressure drop if I were to do this, which I could compensate for by increasing the fan speed.
Any other thoughts?