Seal rooms are the way to go. You still have an exhaust and intake on temperature controlled dampers. You just exchange air two to three times during their nite period to pull out excess oxygen. Other than that there is zero fresh air exchange. In a fresh air room, you pull in air to give plants co2 and control humidity and temp. In a sealed room your dehumidifer, a/c and co2 setup do all that, but better.