Browse Forums Heating, Cooling & Insulation 1 Nov 10, 2010 4:15 pm We have a 25sq brick and tile home at the Gold Coast with roof insulation and ducted air conditioning. We're considering buy one (or two?) of these whirlybird for the roof to try and reduce the need of turning on the aircon this summer. Just wondering if anyone has any knowledge of how effective are these are? Difficulty of installing these onto a tiled roof? And would we need two for a 25sq home? Thanks. Re: Whirlybird air vents 4Nov 11, 2010 6:57 am gcnewbies We have a 25sq brick and tile home at the Gold Coast with roof insulation and ducted air conditioning. We're considering buy one (or two?) of these whirlybird for the roof to try and reduce the need of turning on the aircon this summer. Just wondering if anyone has any knowledge of how effective are these are? Difficulty of installing these onto a tiled roof? And would we need two for a 25sq home? Thanks. http://forums.whirlpool.net.au/forum-replies.cfm?t=843539 Re: Whirlybird air vents 5Nov 13, 2010 7:48 pm I worked with a guy years ago who had a business installing these. He said they made next to no difference. Re: Whirlybird air vents 6Nov 15, 2010 12:15 pm There is also ones called E-Vents. They maybe more suited to colourbond roof though because they are hidden along the roof line,very hard to see them. Block bought 1st RBC X! 2nd Ventrua,Keeper! Pstart 18/7/11 Ethwks jan 2012 Slab Bricks- finished 7/6 Roof Trusses 15/6-cbond 21/7 viewtopic.php?f=31&t=41185 Re: Whirlybird air vents 7Nov 16, 2010 3:52 pm Depending what type you get, a 250mm (throat) vent does about 70m2 (according to manufacturers) and a 300mm vent does around 90m2. You also want to check and see if the insulation is effective. Remember 5 % missing can affect up to 50 % of the total effectiveness. You are best off getting an insulation mob out to check the existing stuff and quote you on the vents. As for diy it is possible, depending on the brand some are harder than others. Eave vents help with these whirlybirds, as they create air flow through the roof space. Nothing can stop your tiles from heating up, and they will remain hot as buggery until evening. Vents slow the heating process up in the morning, and speed the cooling down in the evening. Thats why you need to make sure the batts are installed properly and havent flopped over the years. Re: Whirlybird air vents 9Jan 18, 2011 12:39 pm Throw another into the mix http://universaltileventilators.com.au/ ... -vent.html no need for eave vents Re: Whirlybird air vents 10Feb 03, 2011 10:13 pm I've been reading up on these recently. Have come across a great article that makes sense. If you go a whirly bird you go solar powered for a start. If you go wind powered, the baking hot days with no breeze (when you need it), it wont work Then the next step is to add air vents in your eaves. This then allows the cooled air from outdoors to be pulled through the roof cavity allowing the hot stale air to be sucked out more efficiently. As for anything else (cost, how many needed etc), still reading. Re: Whirlybird air vents 11Feb 17, 2011 3:41 pm I too have examined vents. I have seen some measured performance data on various roof vents which is available from this page (the link to the data is above the photos on the page which opens): http://www.envirosciences.com.au/main/p ... loads.html Certainly, the extraction of air will decrease as wind speed decreases, however, the less restricted the flow path through a roof ventilator, the more air will vent by convection (since they are placed high on the roof). If you examine the data, it indicates that a vent with an internal fan actually moves marginally less air than one without a fan (probably due to a blockage effect of the fan blades)! Bigger isn't always better as the design is important. Any style of vent needs to have a suitable source of replacement air, frequently through eve vents. Effectiveness in reducing "within room" temperature is greatly dependent upon insulation present within the roofspace. Whether the vent has a transparent top or a metal top has next to no impact upon temperature in the roofspace (radiant heat from roof will be the main driver). The site from which the data comes relates a vent which doesn't spin and has a very open air path. Best to view the video on the home page for a quick understanding (originally seen on The New Inventors). Re: Whirlybird air vents 12Feb 25, 2011 3:19 pm We're looking to get 2 whirlybirds for our build. The builder indicates "the weep holes in the brickwork provide sufficient air circulation to the cavity which flows then into the roof space." Is this really enough or should we be pushing for proper eave vents to be put in/are there eave panels that have ventilation holes in them already ? Re: Whirlybird air vents 13Feb 28, 2011 8:16 am A few eve vents would represent a minimal cost, so adding them can only assist in ventilation through the roof cavity. You'd need about 70 holes (100 x 10mm) to equal the "open" area of a 300mm vent. However, a good vent will function with maximum efficiency only if the replacement air required to enter the roof space can do so without restriction, hence the addition of eve vents. The eve vents can always be added as required later, if you choose. Re: Whirlybird air vents 14Feb 28, 2011 11:46 pm I have purchased 3 Maestro Power Vents for our house. According to the box, each one is the eqivelant of 4 wind powered devices. I went with them because the are controled by a thermostat and should only cost about $30 a year to run. In winter you can turn the maestro units them off, a normal whirly bird will continue to pull warm air out of your roof when you are trying to keep warm. I have only installed one so far, but I could quickly feel the difference. http://www.edmonds.com.au/Products/Residential/Roof-Space-Ventilation/Maestro-Power-Vent.aspx Re: Whirlybird air vents 15Mar 06, 2011 7:09 pm I had 3 whirlybirds on my colourbond roof (in Perth), had 2 of them replaced with Maestro solar vents, has made no difference in roof temp than the whirlybirds. My roof temp gets to around 65deg on a 35 deg day. There are other solar vents out there that remove much more air than the Maestro I since found out. Re: Whirlybird air vents 17Mar 06, 2011 7:38 pm I am in no way endorsing them but have a look at westernsolar.com.au they claim one of there vents the SV20 extracts 11,000ltr of air per minute. The Maestro only 1000ltr. Have spoken to the guy from this company an he tells me that he has tested whirlybirds and they extract 1500ltr per minute which is better than the Maestro claims to do. Re: Whirlybird air vents 18Mar 12, 2011 2:25 pm Living in Central Qld in a house orientated the wrong way with a low pitch roof we felt the heat so had two w/birds installed. Can honestly say that we noticed no difference what so ever, and yes one made a continual soft moan after a few years which we ignored. But when the second one started with its noise which resembled a loud constant groan ( scared the kids when they first heard it at night) we said bye bye to them both. We won't be putting any in our new build, we'll put in a quality roof insulation. But that's just our experience I know of others who like them. 12th of Never land 20/3/07 ~~ Contract 17/11/10 ~~ Prestart 9/3/11 ~~ Footings 29/4/11 Re: Whirlybird air vents 19Jan 07, 2013 6:09 pm Argyle I am in no way endorsing them but have a look at westernsolar.com.au they claim one of there vents the SV20 extracts 11,000ltr of air per minute. The Maestro only 1000ltr. Have spoken to the guy from this company an he tells me that he has tested whirlybirds and they extract 1500ltr per minute which is better than the Maestro claims to do. under what conditions, a gale force wind? powered is the way to go Slooowwwwly getting a Manhatten 35 in Middleton Grange 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 13780 How do you remove one of these ceiling air con vents? And is it possible to disconnect the duct joined to the vent from inside the house, without going into the roof cavity? 0 5933 Hi all, sorting out the ducted air con for a 350sqm double story house. Does this placement sound reasonable to you? Also, I plan to have 6 zones I think. Living room… 0 0 |