the ceiling of the cupboard is a large in-line extractor fan, connected to a thermostat.
sucked out of the cupboard and blown outside. The air coming back in is drawn from the garage, through the filter.
that warm air to take the chill of the house. I mean, its just being wasted at the moment.
warm air back outside in the summer, and probably fit a noise baffle.
full of insects? Would it make so little difference as to not be worth the effort?
Why not build a small airing cupboard beside it and use the heat to air clothes. Save on tumble dryer costs. I have the same thoughts about our boiler room which is integral to the house. All that lost heat.