page contents
Home » Home Ventilation » Air Conditioning

Save Money on Air Conditioning with Solar Whiz


During summer roof spaces across Australia can easily reach temperatures of up to 60-70 degrees, depending on the colour and type of roof. Imagine how much of an impact this has on the cost and efficiency of your central ducted air conditioning system!

Roof ventilation is a simple and efficient way to ensure that you have energy-saving air conditioners and the lowest possible cost for operating your air conditioner system.

Reducing the temperature in your roof space (your A/C system’s working environment) from 65 to 40 degreeson a sunny, 30-degree day will make an enormous difference to how well your system runs.

Air conditioning with ventilation

Have a read of our state-specific Cost of Operations documents to see how Solar Whiz helps you keep cool while saving money!


Roof ventilation is a simple and efficient way to ensure that you have energy-saving air conditioners and the lowest possible cost for operating your air cooling systems. The Solar Whiz will run cost-free, every day with zero carbon emissions. Designed to fit walls and most roof types, the Solar Whiz is ideal for house cooling, has a lightweight body, and is maintenance-free.

Easily achieve a cool home with a Solar Whiz used in conjunction with your existing air conditioning system! There are no running costs as the Solar Whiz is a solar-powered ventilator and uses natural ventilation with eave vents to achieve fresh, cool air in your home.

Solar Whiz Ensures That You Have Energy Efficient Air Conditioning

How does it work?

The Solar Whiz air conditioners work by drawing in high volumes of air (1,700m³/hr for an SW-AU-R-28), this eliminates the heat build-up and reduces the heat load on your roof space. Our units extract the hot air surrounding your air conditioner’s unit and ducting, replacing it with cooler outside ambient air, which allows you to increase the energy efficiency of your A/C system. When it doesn’t have to work as hard, your air conditioner will be more effective.

Solar Whiz will save energy by keeping consistent lower internal temperatures, cleaner internal air and you won’t need to run your air conditioner as often.

With our units installed, a 20% increase in efficiency of the air conditioning system is easily achievable. The actual increase in efficiency of your air-con as a result of installing a Solar Whiz roof ventilation fan is of course determined by the temperature drop in the roof space, which can be affected by the quality of the insulated ducting used in your A/C installation.

Energy Efficient Air Conditioners

EPA Victoria’s air conditioning guide outlines a number of ways to keep your home cool by demonstrating styles of air conditioning, and how to help keep your house cooler.

The features outlined in the guide that can reduce the need to operate mechanical cooling and heating include:

  • orientation
  • building materials
  •  insulation
  • air movement—ventilation, fans, and seals
  • windows
  • shading
  • roof and external wall colour

The Air Conditioner Guide states “Ventilation of the roof space (through the use of roof ventilators, eave or gable vents, and/or whole-of-house fans) can assist in removing excess heat from the roof area during summer.”

For a ducted air conditioner, two factors play a significant role in the level of efficiency:

  • The temperature in the (roof) space where the air conditioner is located
  • The heat gain in the ducting between the A/C unit and the delivery point. For example, if the ducting is exposed to hot air in your roof space, the cool air will be heated as it passes through.

Both of these factors can be reduced significantly through effective roof ventilation.

The free-to-operate solar-powered Solar Whiz roof vent is a highly effective way of reducing roof space temperatures and therefore the workload for the air conditioning system and the heat gain in the ducting. On top of that, Solar Whiz works at its best when you need it the most – on clear sunny days!

Solar Roof Fan installed on tin roof

Want the most energy-efficient air conditioner? Improve what you have easily and inexpensively with Solar Whiz!

Installing Solar Whiz saves you energy by increasing the efficiency of your air conditioner. Our units reduce the temperature in your roof space – and therefore the amount of heat that penetrates your ceiling and heats up your house in summer.

When less heat enters your house from the roof space, you don’t need to run your air conditioner as frequently in order to stay comfortable. Therefore helping you cut down your energy bill by reducing the time that you actually need to run the air conditioner – saving you even more money! Basically, Solar Whiz helps you cut costs in two ways: increasing the effectiveness of your air conditioner, and reducing the amount of time you need to operate the system.

Ensuring that your A/C has the best operating conditions available to it by keeping the roof space as close to ambient temperature as possible is easy with Solar Whiz. Once you’ve got good ventilation in your roof-space you can then further maximise the performance of the air conditioner by following the four simple steps as outlined by the Happy Hiller website to reduce your air conditioning bill:

  • Clear any build-up of debris from the vents
  • Close doors and windows
  • Keep heat-producing appliances from thermostats
  • Cover windows/use window shades
  • Shade the outdoor condenser
  • Clear the drain line
  • Insulate any exposed ductwork
  • Change the AC filter regularly
  • Consider installing a zoning system
  • Schedule regular, preventative maintenance of the AC system

Duct Heat Gain Estimate

Duct heat gain is a good way to estimate the value of installing a Solar Whiz, and its role in increasing the efficiency of an existing cooling system.

Duct heat gain is the heat transfer caused by the temperature difference between the ambient air (roof space) and the air flowing inside the air duct. Duct heat gain is affected by the temperature difference, the thickness of the duct insulation layer, air volume, flow rate and the size and shape of the duct.

The calculator on the Whole Building Design Guide (WBDG) website can help you calculate the temperature change of the air passing through the ducts in your home system.

Generally speaking, you can get a rough estimate of the temperature increase of the supply air for the insulated duct as follows:

Supply air velocity
2000 fpm ( 10 m/s )
2000 fpm ( 10 m/s )
Air temperature rise
1°F/100 ft (0.6°C/30 m) duct length
0.75°F/100 ft (0.45°C/30 m) duct length


Night Operation with Solar Whiz

Even though the roof space temperature has been kept at bay during the day by the Solar Whiz – the roof space may still be quite warm after the sun has gone down. It can be beneficial to ventilate your roof at night when the outside air temperature is much lower. This will mean that by the morning, the space will already be quite cool and heat up more slowly.

Solar Whiz, therefore, offers a night operation option – which will enable you to run the Solar Whiz even after sunset.


The Solar Whiz is designed as a high-speed fan with low noise. Get a free quote from our quick quote form.