I mean that's going to depend heavily on insulation, light insulation, how many device you have generating heat (computers, servers, refrigerator, tv), and how

I mean that's going to depend heavily on insulation, light insulation, how many device you have generating heat (computers, servers, refrigerator, tv), and how many times you enter/leave your place. In a well insulated place with airlock-style entrance (even just a mudroom with solid insulation on both doors) where you're blocking out sunlight and not running a ton of electronics, it could easily take hours and hours.