Now considering that solar insolation is around 1000W/m2, imagine beaming 200 bar radiators onto the roof.
How much moving air or water do you think would be required each minute to keep the roof from heating up?
Browse Forums Eco Living Re: Roof space heat - eave vents and whirlybirds ... 23Nov 14, 2009 4:06 pm Builder; Big M Design; Soho 32 Facade; Ascent Blog; http://mickeyb-soho.blogspot.com Trend; viewtopic.php?f=31&t=23990 Re: Roof space heat - eave vents and whirlybirds ... 27Dec 15, 2009 9:16 pm Where you are coming from is where you are going to... Re: Roof space heat - eave vents and whirlybirds ... 30Dec 18, 2009 4:51 pm Where you are coming from is where you are going to... Re: Roof space heat - eave vents and whirlybirds ... 34Feb 12, 2010 12:05 pm Where you are coming from is where you are going to... Re: Roof space heat - eave vents and whirlybirds ... 35Feb 12, 2010 12:43 pm Does insulpaint coating work on the roof? I have also heard of e-vent by Combined Metal Industries and would be interested in them if I needed it living in Perth, thank goodness I requested a surfmist roof. Re: Roof space heat - eave vents and whirlybirds ... 36Feb 12, 2010 1:06 pm I thought I would never had to say this but I am starting to reconsider the whirly debate. A member of another forum who lives in Melbourne has been data logging roof space temperatures during summer. Interestingly he has shown that roof space temperatures don't fall to ambient levels at night time. It makes we wonder if this is inhibiting passive cooling of the building fabric after sunset. This might also be exacerbated by the presence of insulation and radiant foil Although I will maintain that whirlys are insufficient at countering the immense heat load during the day, they may help accelerate roof space cooling at night so that the house can shed its accumulated heat prior to the next day. Of course, this is with the onc_artisan's proviso that night-time temperature do significantly fall. In the past roof space ventilation was advocated for hot/humid climates to improve comfort but paradoxically its benefit may be actually be more appreciated in more moderate climes. This is all speculation of course and a proper study for houses south of Brisbane may be in order. The only concern is that uncontrolled roof space ventilation will not be helpful for retaining heat during winter so some means of blocking it is required during the winter months. Re: Roof space heat - eave vents and whirlybirds ... 37Feb 12, 2010 1:15 pm Good to here some more localised testing is happening Dymonite69... I have to agree. it is my finding also they make a diff' albeit here in the south west. We here are after all on the same latitude a Sydney, so I figure without expiriencial data we are quite blind as to the benefits. And hoping as you know is not good enough. perthhomelover - I imagine you will get a negative response... The thing that concerns me with roof painting, is that paint uses surfactants to help ingress the substrate. Surfactants are what are in your soap ...if you intend to harvest your roof runoff (rainwater) I would advise against it. kind regards, Onc Where you are coming from is where you are going to... Re: Roof space heat - eave vents and whirlybirds ... 38Feb 14, 2010 9:59 pm I have enquired about a solar-powered roof vent which was advertised in a local paper during the week. The product is called Solar Star by Solatube. They claim 1 of them is equivalent to 14 whirlybirds... http://www.sydneydaylight.com.au No pricing on their website, but there is pricing (US$?) on this one: http://www.ecohaus.com/C-22/solarstar+attic+fans Re: Roof space heat - eave vents and whirlybirds ... 39Feb 22, 2010 7:53 am Hi, Can anyone help here please. What is the best height/location to install whirly birds on a house? For example, when looking at the house from the street, should the birds be installed very high on the roof (close to the peak), or further down, maybe half way up the roof height? Other info: Concrete roof tiles, 25 degrees roof pitch, sarking, 2 whirly birds. My signature is distracting people from my wise posts ... Re: Roof space heat - eave vents and whirlybirds ... 40Feb 22, 2010 3:51 pm Seeing as heat rises, wouldn't it be common sense to put them as high as possible? BTW, No response from the company to my email requesting info on the Solar Star a week ago. Slack! (And now 3/3 companies to ignore emails/contact requests through their website in the last few weeks!) 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 3962 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 4061 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 16531 |