Advanced numerical simulations have shown that the risk for mold growth in cold attics can be substantially reduced, and
even eliminated, if the cold attic is sealed and fitted with adaptive ventilation. A basic system would be comprised of mechanical
fans and dampers controlled by attic and outdoor climate sensors installed in a sealed attic without vents. The ventilation system
would run only when the outdoor air has a potential to dry out the attic.

Field tests and extensive measurements over complete annual cycles confirm the simulations and also show that sufficient
airtightness can be achieved in practice with fairly small effort.