• By Liam Ridings
• In Blog, Metal Roofing, Renovation
• Tags roof repairs

Do Whirlybirds Work?

Do whirlybirds work and are they worth installing in your home?

Whirlybirds, otherwise known as roof ventilators or turbine ventilators, are installed on a roof to improve ventilation and reduce heat build-up – but are they really worth the money? Two of the most common questions that we receive around whirlybirds are when should you install them and are they worth the cost.

A very common addition to many Sydney households, whirlybirds are just one of the many ventilation systems available. Whirlybirds do not use any electricity and have been used in Australian homes for years. With so many ventilation systems out there, it’s important to choose one that is going to improve the air quality of your property and reduce reliance on air conditioning and heating devices. The big question is: do whirlybirds work?

This article will break down the basics of roof whirlybirds, how many whirlybirds do I need, and whether or not roof whirlybirds actually work.

What Are Roof Whirlybirds?

Whirlybirds are cylindrical domes that sit on the roof of a building and spin in the wind, creating a vacuum which extracts warm air from the ceiling cavity. When the sun beats down on the roof, it heats the ceiling and roof cavity up to excessive temperatures. As a result, the heat infiltrates the interiors, making the living spaces uncomfortable and stuffy. To compensate for this compensated heat, whirlybirds offer an electricity-free roof ventilator to manage roof space temperatures.

Whirlybirds are designed to extract hot and damp air from roofing spaces, dramatically improving temperatures and increasing the comfort of a property. By removing damp and humid air within a roof void, you eliminate any potential mould or bacteria problems. In summer, whirlybirds minimise excessive temperatures, keeping the spaces nice and cool. During winter, whirlybirds work to remove excess humidity and dampness, preventing mould and bacteria growth.

Installing a whirlybird is an inexpensive way to make your home more energy-efficient, ventilated, and free from odours and stale air. Relying on whirlybirds means less dependence on air conditioning and heating devices. Whirlybirds use no electricity and can spin for more than 20 years when well-maintained; keeping your property comfortable and clean.

Do Whirlybirds Work?

The answer to the question “do whirlybirds work?” is yes. Whirlybirds work to remove hot air from roof voids, effectively ventilating the room or space below. However, whirlybirds are relatively dependant on airflow to function properly. The reason there is varying information on “do whirlybirds actually work?” around is that in areas in which there is little wind, whirlybirds will not function as effectively as they will in high-wind locations.

The roof of a building or house acts as a heat trap. Whirlybirds work to effectively remove the heat that builds up in rooms, by sucking out the hot air. This helps to keep houses and properties ventilated, clean, and prevent the accumulation of hot air. In the hot Australian climate, whirlybirds can do wonders in keeping a space cool during summer.

The Benefits of Roof Whirlybirds

• Remove excess heat
• Helps to minimise mould and dampness
• Improves air quality and removes odours
• Cheap to install and free to run
• Saves on air conditioning and heating costs
• Available in Colorbond colours to suit your roof style

How Do Roof Whirlybirds Work?

So now that we have established that the answer to the question “do whirlybirds work?” is yes, let’s look at how they work. Whirlybird roof ventilators consist of a metal top that is specifically engineered to scoop the wind with fins. As the wind blows into the turbine, the vent rotates. This rotating motion is what creates the vacuum effect that sucks hot air from the interiors of the roof cavity.

All of the heat from roof space gets drawn upwards and into the whirlybird ventilator, which then expels the hot air from the interior of the building. A significant number of whirlybirds will work together to assist in reducing the build-up of heat and humidity, while also enhancing the air quality of the interiors of the house.

The effectiveness of roof whirlybirds is determined by airflow capacity. Airflow capacity of a whirlybird will depend on the whirlybird itself and the space it is installed on. For a whirlybird ventilator that has a diameter of 30cm and a wind speed of 8km per hour, the whirlybird will move almost 10 cubic meters of air per minute from the roof cavity. For a ventilator that has a diameter of 35cm and a wind speed of 25km per hour, the system will move 38 cubic meters per minute.

The design of whirlybirds is entirely waterproof. While the whirlybird is spinning, its circular and rotating force means that any water will be expelled and removed similarly to the vented air.

Often, whirlybirds are teamed with other natural ventilation devices, including soffit vents and ridge vents. Whirlybirds can also be used in conjunction with powered options for a direct and impactful whole-house cooling system.

How Many Whirlybirds Do I Need?

If you’re considering installing roof whirlybirds, you’re probably wondering “how many whirlybirds do I need?”. This is a pretty common question. Whirlybirds work very well and will only increase the ventilation in a house when multiple are installed. The size of your house should determine the number of whirlybirds you install. Here’s a rough guide:

• 1-2 Bedroom Home: 2 Roof Whirlybird Units
• 3-4 Bedroom Home: 3-4 Roof whirlybird Units
• 4-5 Bedroom Home: 4 Roof Whirlybird Units

Vertec Roofing Whirlybird Installation

At Vertec Roofing, we pride ourselves on our commitment to quality. While still offering our services at reasonable rates, we only use the best quality roof whirlybirds. We complete whirlybird installation Sydney on both metal and tile roofs to ensure that your property is kept safe from damp and humid roofing issues.

If you’d like to learn more about what whirlybird installation can do for you, get in touch with one of our experts today. Our roofing contractors are experienced, knowledgeable, and offer professional advice on your roofing project with a no-obligation quote.