Have you ever stuck your head into a ceiling cavity during hot weather? If so, it’s no surprise how the space between your ceiling and roof can get so hot.
Roof insulation helps to reflect heat, but can be a drawback by sealing air and moisture in. This in turn creates a hot-house effect and is prime breeding ground for fungi to flourish. The ideal solution is a combination of insulation and ventilation.
Whirlybird – this ingenious simple device is the most common type of roof ventilator. A cylindrical dome which spins when it catches a breeze. This causes the turbine to spin in the wind to create a vacuum by extracting warm air from the roof cavity. Whirlybirds are not without controversy. Ventilation professionals argue that they do work, but only if you install enough of them. One whirlybird is not usually enough even for a modest sized roof.
A further downside is they cannot be “turned off” during winter causing your home to lose heat. And when we need it the most in Summer, the Whirlybird ventilator which is designed to spin and draw out hot heat from your roof, will struggle to spin at all, on a hot dry summer day. Despite criticisms, whirlybirds are easy to install and provide an alternative to expensive ventilation systems.
Solar powered vents – these are growing in popularity. A solar powered vent contains a small solar panel which powers an exhaust fan inside the frame. They can be very effective, but have no power storage capacity, and don’t work at night. Advocates argue that this doesn’t matter, though, because they are needed most during the day. Because they rely on solar energy instead of wind energy, they are not as obtrusive as whirlybirds, which must be tall enough to catch breezes and do not operate in winter so keeping the heat in your roof when most needed.
Electric powered roof vents – Considered the most effective because they around the clock. Manufacturers claim they are eight times as effective as whirlybirds. But, installation requires a licensed electrician which adds to initial costs. They will also contribute to your energy consumption. Advocates of electric roof ventilation systems claim the savings to cooling costs outweigh the cost of running the vents.
There are many arguments for and against every type of roof ventilation system. Most roof ventilation suppliers offer several options because there is no “one size fits all” system.
You can install whirlybird vents and forget them. If the right size vents are installed and you get the right number of whirlybirds, they may be all you need. Remember though, in winter you will lose that precious heat in your roof meaning ineffective heating during cold weather. So, solar powered roof vents might be the perfect solution for your home.
If you live in a very hot climate or have a problem with humidity, you may need electric vents. The best thing to do is to ask local suppliers and installers for their opinions. Then take a good look at the product specifications and make your decision based on your needs rather than price. After all, there’s no sense spending more than you need to for the latest thing or less than you should for a roof vent that isn’t efficient enough for your home.
To learn more about the best roof ventilation for your home, contact the experts at Roof & Render SA.