Good ventilation brings fresh air into a home 24 hours a day. And that’s important for a healthy indoor air climate. If you don’t ventilate, or don’t ventilate enough, the risk of health problems increases. This can be due to mould growth caused by moisture released by showering, washing, and breathing. Or through harmful substances released during frying. Fresh ventilation air enters the home from outside. But if the outdoor air is polluted, then ventilating will do just the opposite, bringing unwanted substances into the home. This can be mitigated when building or converting a house by making sure it is known on which side of the building the air is least polluted. This may vary from one property to another. Drawing in ventilation air on the cleanest side improves the air quality in the home. The side of an existing or planned house that’s exposed to the least air pollution is usually the rear of the building, which is as far as possible from the road.
Case study: the Prince Willem Alexander school is located on The Hague’s central ring road. A busy road where concentrations of soot, particulate matter, and nitrogen dioxide are greatly elevated. Our advice was therefore to draw ventilation air as far from the road as possible. The air intake was therefore moved to the back of the school building. This resulted in a 27% lower nitrogen dioxide concentration in the classrooms!