Really that much money to fit a fan?

[IJWS15]

Bit excessive. Mine didn't when I had to take my MVHR offline for a fortnight but I understand that you're being deliberately obtuse. Someone who has had the foresight to create or buy a well draughtproofed home with an MVHR would hopefully also understand the need to arrange alternative ventilation if the regular system were down for any reason.

The bigger problem is general ignorance, as the number of MVHR enabled homes rise it's quite likely that the number of occupants who have no idea what it is, where it is or how it works will also rise. That's the same story with many things though and we have professionals for those things (consumer units, gas boilers) to compensate for the ignorant population

My son had a new build flat with an MVHR, worked a treat until my wife started to get respiratory problems when we visited.

How many people with these systems know they need to clean the filters . . . . doing that fixed the respiratory problems.