News Item - September 2011
"Study disproves claims that roof space air can be used for effective domestic heating and cooling."
Claims that positive pressure ventilation systems that draw air from roof spaces can provide effective heating and cooling have been shown to be unsubstantiated.
This is the conclusion of a recent study by the University of Otago New Zealand titled
The study showed that " that small potential heating and cooling benefits were possible at certain times from pumping air from the roof space into the living areas of some New Zealand houses. However those potential benefits were not large enough to significantly alter the indoor air temperature on average."
and that " the majority of the time, it was calculated that pumping air from the roof space into the house would provide no heating or cooling benefit. In fact, this would often actually act to push the internal temperature further away from the desired level rather than closer to it."
In a press release , Consumer NZ (New Zealand's National Consumer organization) "welcomed the results" and stated " Consumer looks forward to the end of advertising that makes misleading claims about the heating or cooling benefits from positive-pressure type ventilation systems. These ventilation systems should only be promoted on their ability to control condensation by providing adequate ventilation."