Ventilation science seems to suggest that the closer you can get to being outside, the better. And that…

Ventilation science seems to suggest that the closer you can get to being outside, the better. And that includes light and humidity, as well as air. I wonder if the old school opening windows, with upper opening clerestory windows and/or vents, has ever been bettered. /1 https://t.co/Hg2N4Epnun

There’s the worry about winter, about how this can work when it’s cold. But it appears you don’t need these open much, to get good ventilation. My house is over 100 years old, and it’s bloody cold here right now. There are no windows open, but CO2 readings are excellent. /2

We also have modern double-glazed windows, the house doesn’t leak a lot. But we have upper wall vents, like this one, designed into the house originally to remove exhaust gases from coal and gas fires. Ventilation experts have advised we seal them, because of heat loss. /3 https://t.co/mZ2F76GEpH

We haven’t done that, and I’m glad. It seems to create good ventilation in the home, even in deep winter, without any noticeable draughts of cold air or enormous heat loss impact on heating bills. Tilt and turn double-glazing is also useful because the tilt setting…/4

…allows for ventilation without draughts. Most commercial buildings moved to almost hermetic sealing, relying entirely upon HVAC. I do wonder if that was a terrible mistake in building design. /end

P.S. I’m also persuaded that encouraging more ‘vertical’ ventilation in this way is better than cross-ventilation, which tends to shift dirty air across a room, from person to person, rather than exhausting the dirty air up and out.