Whirlybirds are seen as a staple of roof ventilation in Australia. Most people will be familiar with the site of a whirlybird installed on the roof of a home or business.
While it’s not entirely clear who came up with the first design for the whirlybird, the design for a turbine air vent has been used in houses since the first half of the 20th century. The design has not changed much over time, despite the leaps and bounds we have made in technology over the last 70 years. This page looks at the challenges and limitations associated with a whirlybird installation.
The Downside of a Whirlybird Installation
Whirlybirds operate using wind power (and a little bit of heat convection). They rely mostly on the wind to spin the turbines which creates a vacuum that drags the hot air out of the house. Rising and expanding heat can also help this process as built-up heat ‘balloons’ and can push its way out of the turbine.
However, relying on wind power to operate a whirlybird installation has a lot of limitations. When there is not enough wind, the whirlybird’s performance will be severely reduced.
Furthermore, even in ideal conditions, whirlybirds cannot extract much heat because they do not have a very high airflow rating. The average whirlybird can move around 100m³/h (cubic metres of air per hour), which is nowhere near enough to have a meaningful effect on the temperature and air quality in your building. There are a variety of factors that need to be considered when determining how much ventilation your building needs, including size and recommended air changes per hour.
At Solar Whiz, our smallest unit moves 1200m³/h; that’s 12 times more powerful than a single whirlybird!
Whirlybirds are noisy.
Many sources say that a working whirlybird should operate at a low hum or whirring sound level. However, there are multitudes of sites and pages that talk about this issue. If the whirlybird is only noisy when it is broken, and everyone who has one complains about the noise, then there seems to be a serious problem!
Whirlybirds frequently get bent, rusted, and worn out, which will cause the turbine vent to grate and create a lot of noise.
Our SMALLEST unit is 12 times more powerful than a whirlybird
The High Cost of Whirlybird Installation
Expensive Installation Fees
Many people feel that a powered fan like Solar Whiz is too expensive and opt for a traditional whirlybird instead. There are many cheap whirlybirds available on the market, but these are notorious for causing problems for the owner. In order to avoid issues relating to poor product quality and installation problems, you would need to purchase from a reputable brand. However, if you consider that a higher quality whirlybird will cost more (plus you will need multiple units, costing you more in installation fees) you are not really saving that much money.
Whirlybirds require regular cleaning and upkeep to ensure that they work properly. The turbines need to be cleared of debris and the bearings need to be lubricated.
Over time, debris such as leaves can get stuck in the turbine blades, limiting the amount of air that the units can move. Additionally, the ball bearings that allow the whirlybird to spin can get worn out or rusted over time. These issues will impact the (already limited) effectiveness of the unit and generate squeaking or grating noises.
It can be difficult to clean and maintain the whirlybird unit yourself, especially if the whirlybird is installed on a steep and/or inaccessible roof. If that is the case, you will need to pay for someone to clean it for you. Over time, these costs will add up to quite a bit of money!
Solar Whiz units do not require regular maintenance and use brushless motors. Brushless motors are quieter and last longer than electrical motors or ball-bearing parts. This further cuts down on any costs that you might encounter after installing your unit.
Maintenance and Upkeep of a Whirlybird
Regular Cleaning is Essential
As mentioned before, it is essential that you regularly clean and maintain an installed whirlybird. Debris and dust particles can accumulate over time, impacting the whirlybird’s performance. Built-up debris can limit how effectively the unit removes heat, moisture, and pollution from your house, if the unit even works at all! Regular maintenance is necessary to avoid damage and maximise effectiveness.
Repairs Can Be Costly
If the installed whirlybird gets damaged or goes a long period of time without cleaning, you will most likely have to replace the whole unit. Because whirlybirds are designed to work as a single part, if it gets damaged you can’t fix the problem without getting an entirely new unit. That means that you can’t just fix a ball bearing or a broken turbine.
If a whirlybird gets damaged you will need to pay for a new one, and pay to get it installed again.
Solar Whiz units are far less likely to have any operational issues. Any problems that do occur are likely to be related to parts that can be easily fixed or re-wired without removing the unit from the building.
Is a Whirlybird Installation Right For You?
Consider Your Ventilation Needs
Whirlybirds may not be effective in all situations. Remember, an average domestic whirlybird only moves around 100-150 m³/h in 12 km/h winds individually and the general recommendation is one whirlybird per 50m2 of roof space.
Our recommendation at Solar Whiz is a minimum airflow capacity of 700m³/h. We find that this is the minimum airflow rating for a noticeable impact. That means you would need a minimum of 5-7 whirlybirds installed to notice any difference in temperature or air quality in your house.
Solar Whiz offers 3 domestic units, the smallest of which has an airflow capacity of 1200m³/h. Our largest domestic unit moves 2300m³/h. That’s equal to the function of 12 and 23 whirlybirds respectively.
If you need to ventilate your home, we strongly recommend that you consider these numbers. In our experience, installing whirlybirds on your house just won’t make a difference.
Weigh the Costs
Determine if the cost of installing a whirlybird and maintaining it is worth it. As we’ve discussed through this page, installing multiple whirlybird fans can quickly add up in costs. Considering also the cost to keep the fans running properly and you’ll find that whirlybirds are actually quite expensive.
Whirlybird installations can quite easily become a risk and constant worry. A Solar Whiz unit is a much more reliable, efficient, and longer-lasting product. If you’re serious about ventilating your home our fans are the ones for you.