Supply ventilation creates positive indoor pressure.
This is advantageous in moderate and hot climates
because positive pressure avoids pulling hot, humid
air into wall cavities where condensation problems
can occur. In cold climates, positive pressure can
possibly lead to moisture problems if hot, moist air
is forced into wall cavities where condensation is
likely to occur. In addition, supply ventilation
systems avoid “back drafting” combustion gases
from appliances and fireplaces into homes.
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