When it's around 20C, it's impossible for me to make my rooms colder than say 23C, because there is no way I can make so much of air exchange. Even if I someho

When it's around 20C, it's impossible for me to make my rooms colder than say 23C, because there is no way I can make so much of air exchange. Even if I somehow manage to pull the air in, the moment I close it - the walls that have all that heat will start giving it back again, bringing the temperature back to where it was. It's so funny, that when the winter starts, it's long into the winter before I have to turn on heating in my apartment.