Re: Positive Input Ventilation
Malcolm's on the right track (for a change).
Although, I realize that cold, bleak, miserable Britain is different from warm, tropical, Pumicestone Passage paradise.
Here, if it's too warm - or even 'hot' - I peel off clothing and open all the windows to let the sea breezes waft through.
Too cool or even cold (rarely), I simply don more warm gear, close the windows a bit and (very rarely) switch on a heater.