Ideally you want to underfloor ventilation if the replacement air is dry. As being the temperature is greater during the day the relative humidity is decreased, so the choice could well be to operate your sub-floor ventilation program during the day – and stay clear of operating it through damp http://sergiotsrah.acidblog.net/13233532/the-smart-trick-of-sub-floor-vent-that-no-one-is-discussing