Building tight prevents conditioned (heated in winter, cooled in summer) inside air from escaping, causing you to lose/waste money. It also prevents bad outside air (bugs, pollen, dust, car pollution, too humid/dry/cold/hot) from coming in.
Ventilating right means taking stale air from bathrooms (humidity) and kitchens (cooking VOCs) and exhausting it, and at the same time bringing in fresh air from outside on your terms: through filters and tempered to match inside conditions. This is usually done with HRV/ERVs.
Harder to do with older homes that need to be renovated, but now part of the building code for new builds in many areas (ASHRAE 62 defines ventilation volume/rate requirements).
Not exactly. What you heat is the inside of your rooms, and a significant part of that heat can be felt as infrared radiation. When you ventilate in a quick and intensive manner, you exchange the air, which becomes cold for a few minutes but you do not cool down the room - because that takes longer. And the cold air has very little mass, so it is easy to re-heat again, and will be warmed by the walls etc.
The energy stored in your walls is much higher than the energy stored in the air. Swapping out all the air for cold one will reduce the total energy stored in your house very little. The walls will reheat the air. Same with letting AC air escape for a minute or two.
Buy a co2 meter. You have to have windows opened for much more than 5 minutes. Aaaand you have to open them every 40 minutes, even when you sleep. Good luck with that.
For smaller homes switching from convection to infrared heating helps a lot, heating the surfaces instead of the air, means that letting the air mix by opening a window is less of a problem.
Not very useful when it is -10C (or colder) outside.
Current building science best practice can be summed up in the saying "Build tight and ventilate right.".
* https://www.energy.gov/indianenergy/articles/build-tight-ven...
* https://www.nrel.gov/docs/fy03osti/26458.pdf
Building tight prevents conditioned (heated in winter, cooled in summer) inside air from escaping, causing you to lose/waste money. It also prevents bad outside air (bugs, pollen, dust, car pollution, too humid/dry/cold/hot) from coming in.
Ventilating right means taking stale air from bathrooms (humidity) and kitchens (cooking VOCs) and exhausting it, and at the same time bringing in fresh air from outside on your terms: through filters and tempered to match inside conditions. This is usually done with HRV/ERVs.
Harder to do with older homes that need to be renovated, but now part of the building code for new builds in many areas (ASHRAE 62 defines ventilation volume/rate requirements).