I will also put the air supply with 1.7 kW heater + 2.5 kW convector, my area is only 20 m2, the green room is insulated and overpressurized, so called clean room, no dust on the air supply side! The second room is negative pressure and will be less insulated to avoid condensation. So, the only thing left to do is the testing. The air change per hour for 20 m2 is no more than 200 cubic meters per hour. 5 ventilators will work in the supply exhaust unit. Total room consumption 4,85 kw