this video shows why you need to get HVAC and ventilation done right.
thats in Houstan texas, so more humid than here but also hotter. its also an extreme example.
all the mold is simply from humid outside air being sucked into the house and hitting cold spots. the cause of the air leaking in so much is due to the HVAC (eg ducted heat pump) has to much leakage from the ducts. ie its sucking more air out of the house than its blowing into the house.
for those who will say its lack of ventilation, i suspect it has plenty of ventilation. but ventilation pulls in damp outside air and its pulling it through the cold walls/ceiling/etc where it condensates.
this is why you want positive pressure in the house so dry air is being pushed through the walls instead of humid air.
having the HVAC unit and ducts inside the house would have helped a lot. also making the house air tight so you don't have humid air leaking in through the wood work.
ducted heatpumps are getting more popular here, but they come with risks.
Trusted
