Browse Forums Eco Living Re: Roof space heat - eave vents and whirlybirds ... 20Oct 28, 2009 7:24 pm dymonite69 In the absence of a radiant barrier, ventilating a roof space with a whirly is insignificant. - Natural convection in the roof space results in a much cool boundary layer at the top surface of the ceiling (lower than the mean air temperature) And guess what will happen to that boundary layer if you introduce enough ventilation to stir up the air space without actually allowing enough air out to take much heat away! I believe an experiment could well find that only having a couple of eave vents or a single small whirlybird could be worse than having none at all. "Now, supposing a house to have a southern aspect, sunshine during winter will steal in under the verandah, but in summer, when the sun traverses a path right over our heads, the roof will afford an agreeable shade, will it not?" -- Socrates, ca. 400 BC Shade the brick with large eves. Since going to minimum of 600mm eaves on my build, I've noticed much improved cooling off the house after hot summer days. Can see the… 1 815 Old Home Restoration / Renovation Cheers mate! This is exactly what I was thinking but wasn't sure if it was something I'd find on the shelf. I agree with you, fixing the brackets to the board will look… 2 3337 retail its around double the price of a similar sized actron/dakin system from memory, They are excellent systems though. But with how builder gouge on AC/heating, you… 4 16292 |