Whole House Fans

Efficient Low Cost Cooling: The best thing about a Whole House Fan is how cheap they are to run

One Whole House Fan running at maximum speed uses less electricity than three ceiling fans and yet it cools the whole house!

Your Whole House Fan costs about 10c per hour to run. Typical usage of your Whole House Fan is less than $1 per day. This is far less than even a moderately sized room air conditioner which would cost close to $1 per hour to run or $10 per day and that doesn't even cool your whole house!

Even on a really hot day your whole house fan can dramatically reduce your air-conditioning bill. In the cool of the morning you run the Whole House Fan to pull all the cold morning air into the house cooling it down.

Then you shut the windows and draw your curtains and blinds.

A sealed house where the structure is cool, the air is cool and the roof space is cool takes a lot of time to heat up.

If you have your Whole House Fan running at low speed and open a small window very close to your ceiling vent for the Whole House Fan in say a bathroom, this will vent the roof space preventing it from getting too hot and helping to keep your house temperature cool.

This is similar to when you take your esky out on a hot day. You are storing the "cool" to keep yourself cool for most of the day.

If that fails you supplement your cooling with some air-conditioning but instead of running it for 24 hours you might only need it for a few hours during the hottest part of the day. When the outside temp drops again you just open your windows and let the Whole House Fan bring in the cool natural air.

There is nothing more pleasant than sleeping at night with a cool natural breeze of fresh air wafting in your windows even on a perfectly still night courtesy of your Whole House Fan.

When your house is cool and you just want a pleasant breeze for the night while you sleep, you turn down the speed to suit your comfort and the fan is barely audible.

How noisy is the Whole House Fan?

The noise from a Whole House Fan is just the noise of air rushing through the duct and out of your house.

It has been described as a dull rumble. Some customers have said they love the sound of it as it is like white noise.

Even people who comment about hearing the fan running say within a day or two they no longer notice it.

To meaure the noise of the Whole House Fan prototype I have installed, I measured the sound level at 3 different points in the house at varying fan speeds. The results are shown below.

As you can see from the chart of noise measurements below, the reason the noise is hardly noticeable is because it is very low.

To compare, our bathroom exhaust fan is 57dBA when standing directly underneath it. It is also a far more annoying sound as it is higher frequency.

So how quiet are these measurements? Noise levels in a quiet suburb are about 50dBA and the noise level in a library is 40dBA.

Ceiling mounted exhaust fans and air conditioning fans produce significant noise by vibrating the ceiling which then acts as a drum sending the noise into your house. Our units are not ceiling mounted. They are vibration isolated and mounted near the peak of the roof.

Installation

Installing a whole house fan is straightforward. An electrician can install it for you quite simply. If you are in South East Queensland, or New South Wales, we have installers who can do the job for you.

All you see from inside your home is the air inlet grill in the ceiling which is about 550mmx550mm.

Efficiency Designed In: We use EC motors (Electronically Commutated) in our fans. Why this is important

Old style American Whole House Fans were great at moving lots of air but sound like an industrial blower. Not so good for when you are trying to sleep.

These motors had only two or three speeds to choose from and the fan was mounted right over the ceiling on the rafters so the noise levels were pretty high.

Our EC motors are amongst the most advanced electric motors available.

They are brushless so they are very low maintenance and very long life.

EC motors are quieter than traditional inefficient motors.

They use permanent magnets and electronic speed controllers so they are extremely efficient.

EC motors are typically two or three times more efficent than similar sized induction motors used in air conditioning fans.

This high efficiency means EC motors run much cooler than their counterparts. This increases the life of windings and bearings.

Efficiency will vary depending on the manufacturer, power rating and load conditions. However, as a general rule of thumb, shaded pole motors range from 15-25% efficiency, permanent split capacitor motors range from 30-50% efficiency and EC motors achieve 60-75+% efficiency.

The electronic speed controller allows inifinitely variable speed settings so you can adjust your fan to the setting you want rather than just what the motor allows.

Save Money: How much you can save with a Whole House Fan

If you have fully ducted airconditioning your running cost over 10 years is about $31,500. You could save around $6,300 over 10 years by installing and using a Whole House Fan in conjunction with your airconditioning.

If you have 3 small room airconditioners your running cost over 10 years is about $13,500. You could save around $2,700 over 10 years by installing and using a Whole House Fan in conjunction with your airconditioners.

Based on data from energyrating.gov.au, 28.5c kWh power cost, 5 months a year of cooling at 12 hours per day, 23% reduction using whole house fan and 90% more efficient than air conditioner, ducted airconditioner 21kW capacity and room airconditioners at 3kW capacity each.