Some ideas if you’re trying to improve ventilation
- small openings are quite effective in cold weather - big temp difference = more flow
- regular airing 10 min per hr can be nearly as good as constant opening, especially if you leave the room
1/

- more than one opening is good - go for opposite sides of room or high and low openings if you can
- high level openings can help ventilate with less cold drafts
- as well as windows make sure background trickle vents are open
- if you have mech vent set to full fresh air 2/

- if ventilation is tricky air cleaners can help - look for UVC or HEPA as most reliable with a high CADR
- don’t forget that distance, duration, face coverings, hand washing and cleaning high touch surfaces matter too. No one measure will work alone.