Building experts are pushing for ventilation systems to be mandatory in all new homes to help curb Covid-19 and other airborne diseases.
The Building Research Association is testing the air quality in 200 homes, examining how better air circulation can help reduce the amount of carbon dioxide and other pollutants in rooms.
If an indoor space does not have adequate ventilation, the breath stays in the air longer, increasing the risk of those inside catching a virus.
Experts say a room must contain less than 800 parts per million (ppm) of carbon dioxide to be considered properly ventilated.
But tests have shown that being in a room with several people and no open window or other form of ventilation means the concentration of carbon dioxide rises rapidly.
“Indoors, pollutants in the air can be up to 100 times worse than outdoors,” said Julie Bennett of the University of Otago.
“It’s really problematic because we spend all our time, 90% of our day indoors.”
For existing homes, devices such as portable air purifiers are available, but NIWA air quality scientist Ian Longley says simply opening the windows is often enough.
“A lot of people might think that in winter I can’t open my windows and doors, it’s too cold,” Longley told 1News.
“But in fact, science and studies show that you can open them up a bit and that’s enough to give the ventilation a big boost.”
The Covid-19 pandemic has created a much greater awareness on ventilation, with 5,000 portable air purifiers distributed to schools.