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Many people are familiar with whirlybirds, what they do and how they work. However, a whirlybird installation comes with a large number of drawbacks that you might not be aware of. Make sure you read up about these surprising facts before you buy a whirlybird of your own!

1. Whirlybirds Are Noisy

disadvantages of whirlybirdsMany businesses that sell whirlybirds will tell you that the fans operate quietly. Often they claim that if their product is making noise it’s because of a solvable issue. It’s true that when a whirlybird is working properly, they run silently.

However, this doesn’t change the fact that almost everyone who has whirlybirds complains about the noise. Whirlybirds can easily get bent or rusted and the bearings that allow them to spin can easily get worn out. Any of these issues will cause the unit to make a grating or squeaking sound as it spins.


2. Whirly birds Are Dependent on Massive Amounts of Airflow to Function Properly

Whirly birds work primarily by spinning to create a vacuum that sucks hot air out of your roof space. This process relies on a wind strong enough to spin the turbines. As a result, if there is no wind, it doesn’t spin properly. Although whirly birds can still spin in still conditions due to heat convection pushing the blades from the inside, the effect won’t be anywhere near what you need it to be.
Even in ideal conditions, whirly birds have an airflow capacity of about 100-150 m³/h in 12 km/h winds (varies according to design). This is still drastically under-ventilating a space. We recommend that a small space will probably need at least 700 m³/h of airflow to make a difference.
Australia is prone to still and hot summer days. In these conditions, a whirly bird simply won’t deliver the results you need to keep you cool.

3. Whirly Birds Are Inefficient in Removing Moisture in Colder Months

It is important to ventilate your roof space during winter to keep moisture and condensation levels as low as possible. While Australia is known for our long hot summers, the winters can still be cold and very wet. This can cause a build-up of moisture in the house that can lead to mould growth. An efficient ventilation system will keep you healthy and comfortable through the winter months.

Whirly birds will continue to operate as long as there is wind to spin the turbines. However, because of their limited airflow capacity, they won’t be able to extract much moisture from your roof. As a result, you may just be losing valuable heat from your home.


4. Whirlybirds are Prone to Malfunction

Many people worry that whirlybirds will leak in the rain. This is a misconception as the design prevents rain from getting in. What you should be concerned about is the debris that can get caught in the turbines. Because of the open design, it is possible for dust and leave to get stuck in the turbines. This can cause the unit to stop spinning like it should and leave it open to rust. Many whirlybird owners struggle with their units rusting over time. These problems prevent the unit from ventilating your home like it should.

5.Whirlybirds Require Periodic Maintenance

Due to the moving parts in a whirly bird and the design features that collect debris, the unit will need to be maintained to prevent noise. You will need to occasionally clean out your unit to prevent it from getting clogged up by leaves and other foreign objects.
As the moving parts are used (do their job), they tend to wear down. This can lead to squeaks and grinding in the bearings which can be especially annoying because there is no off switch! That means you’ll have to get up on the roof and lubricate the moving parts every now and then.

6. Whirly birds Are More Expensive Than You Think

As mentioned above, whirly birds can make a lot of noise when they aren’t installed properly or if they get damaged. To avoid these kinds of problems, you would need to buy a more expensive whirly birds from a more reputable brand. You will also need a roofer to install the unit for you. Both of these things will bump up the cost of your whirlybird installation. So much for a cheap and easy roof ventilation option!

Furthermore, a tendency to malfunction which means whirly birds require periodic maintenance. It can be costly to have your fan maintained and/or fixed whenever something goes wrong (which could be often). Many brands claim that a whirly bird is a great ‘set and forget’ ventilation option, but this clearly isn’t the case.

While individual whirly bird units might not be that expensive, the costs can add up quickly. Most businesses recommend at least 1 unit per 50-90m2 of roof space. That means that most homes will need more than one unit. Our smallest unit is as powerful as 12 whirlybirds! Evidently, it is far more cost effective to pay more upfront for a more reliable and powerful roof ventilation system like Solar Whiz.


home solar whirlybird

Consider Buying a Whirlybird Alternative

With these common problems that stop whirlybirds from working like it should, we strongly encourage you to look at more durable roof ventilation options. Solar Whiz’s solar whirlybirds are much more resilient, and far more powerful than any traditional whirlybird on the market.

Solar Whiz is an Australian-made product designed for the harsh environments this country has to offer. If you need something to powerfully and effectively extract hot air from your roof space, check out Solar Whiz. Our solar whirlybird has an airflow capacity of up to 2300 m3/h, compared to just 100 m3/h for regular whirlybirds.

Don’t delay! Find out more about how our roof ventilation units can save you money, keep you cool and improve the indoor air quality!


Frequently Asked Questions

Are whirlybirds effective at cooling a roof?

Whirlybirds can provide some cooling benefits, but they may not be as effective as other ventilation systems. Their effectiveness depends on various factors, and in some cases, additional ventilation solutions may be required for optimal cooling.

Do whirlybirds require maintenance?

Whirlybirds require periodic maintenance, such as cleaning and lubricating to function properly.

Do whirlybirds work in all weather conditions?

Whirlybirds work best in windy conditions but can still be effective in mild to moderate wind speeds. However, they may not be as effective in calm or still conditions.

Are there any building code requirements for installing whirlybirds?

Building code requirements for whirlybird installation can vary depending on your location. It’s best to consult with a professional installer or your local building authority to ensure compliance with any relevant regulations.

Are whirlybirds effective at reducing humidity levels?

While whirlybirds can help improve ventilation and reduce moisture in the roof space, they may not be as effective at reducing high humidity levels. In areas with extremely high humidity, additional ventilation solutions may be required.

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