When towns grew during the 1700s with increased overcrowding and the absence of adequate sanitation, health issues became increasingly urgent. Suspicions arose that some diseases are airborne. Ventilation for healthy indoor air thus had a high priority, especially in buildings where it was specifically noted that illnesses and disease spread, namely in prisons, ships, troop barracks and ironically even in hospitals. Around 1770 there was a scientific evidence that fresh air is actually more healthy than tainted indoor air, as it is also known that indoor air contains high levels of carbon dioxide, water vapor and contaminants from for example fuel lamps.
August 3, 2015