About wind turbine ventilation

How does good ventilation benefit you?

Your Health

Good ventilation protects you, your family, and your guests, your staff and your customers from unpleasant odours, irritating pollutants, and potentially dangerous gases like carbon monoxide. Good ventilation also prevents the growth of mould and mildew, which can cause or aggravate allergic reactions and lung problems such as asthma.  Click here to read about more health benefits.

Your home / office / warehouse

Good ventilation protects your buildings from damage by eliminating excess moisture from the air. Too much moisture rots window sills, attic eaves and roof timbers, peels paint, and invites insect infestation.  Metal fittings can rust.  Damp insulation in walls and ceilings means lost heat, higher fuel bills, and destructive mould growth. Carpeting, wallpaper, electronic equipment, and furniture can all be damaged by excess moisture.

Carbon savings and Environmental Impact

Case study projects on natural ventilation have shown a saving of between 24% and 71% of carbon emissions compared to the industry benchmark figures for an average air conditioned building.

Roof turbine vents (whirly vents) are powered by the air, and they don’t require any additional electrical power. That in itself has an immense impact on the environment, helping you, the business and homeowner, significantly reduce your carbon footprint.

Now there is a raised consciousness to be environmentally responsible by consuming less energy, turbine ventilators is your answer for cooling.

Maybe this is the time to consider using whirly vent wind turbine ventilators for all of your buildings, being GREEN does not have to be expensive. 

How does natural wind turbine ventilation work?

How air movement works is very simple.  The old adage "hot air rises" is true.  The hot air inside your building rises up to the top of the building (absorbing excess moisture).  When the turbines rotate, they suck this warm moist air out through the roof vent, thereby dropping the temperature in the building and allowing the supply of fresh air through vents (and doors and windows when they are open).  Because roof turbine ventilators are located at the highest point of the roof this provides fantastic ventilation.  A huge advantage of wind turbine ventilation is it is draught free (unlike an open window).

Air naturally separates into layers with temperature and moisture.  Fact sheets confirm that with every 10°C increase in temperature, the moisture-holding capacity of the air approximately doubles.

Natural ventilation systems rely on pressure differences to move fresh air through your building.  Pressure differences can be caused by wind or the buoyancy effect created by temperature differences or differences in humidity (between the inside and the outside of a building).  It is useful to think of a natural ventilation system as a circuit, fresh air needs to be able to enter and circulate in the building replacing the stale air that is being drawn through the roof mounted wind turbine ventilator.  It is, therefore, important to make sure their are openings between rooms.  Windows, louvers, grills, or open plans are methods to complete the airflow circuit once you have installed your roof vent.

So in summary, a wind turbine ventilator provides a form of natural ventilation, moving air continually that draws stale air out of the building while the grills / louvres etc are letting cleaner, cool air in from outside.  The turbine is a free-spinning roof ventilator, which uses a combination of wind energy and convection to facilitate air changes. 

wind turbine ventilation - Bernoulli's Principle

The blades of the wind turbine ventilator add to the effectiveness of the ventilation:-

• as the breeze turns the ventilator, it creates an area of low pressure on the leeward side of the turbine. This low pressure zone is fed by drawing air from inside the building through the turbine, causing a continuous extraction of stale hot air from the building; and
• as the turbine rotates, the centripetal forces associated with the rotation fling air outwards to the tips of the vanes. This draws air from the building through the throat of the ventilator causing continuous ventilation.

When your building is hot and there is no breeze - An important feature wind turbines is they even when there is no wind.  The hot air (thermal currents) cause the ventilator to rotate drawing hot stale air out of the building and creating continuous ventilation.

Effective cooling and moisture removal in ceilings / attic spaces

Roof mounted wind turbine ventilators commonly referred to as whirlybird vents are now a regular item on homes in countries like Australia.  They are steadily becoming a more common site on residential homes, upmarket lodges etc in Africa.  In buildings with ceilings and no attic ventilation the heat gets trapped in the ceiling and radiates down into the building.  This causes extreme discomfort for the people working and living there.

Often people do not realise that proper ventilation is as important in winter as it is in summer.  It is estimated that bathrooms and kitchens put as much as 12 litres or water per day into your home.  A wind turbine ventilator draws this excess moisture out of your building. 

RoofWhirlys4Africa roof top wind turbine ventilators have several advantages

These include they do not need to be powered by electricity, they are located such that they exhaust the hottest air first, they do not cause any harm what so ever to the environment, they tend to save a lot of money because there is no operating cost plus they are maintenance free.

They are also strong and anti-corrosive.   They are designed to be rainwater and bird proof.  The ventilators are also designed in a way that prevents leakage and down draft into the building.

Vertical vanes

An Australian study by Revel compared ventilation rates between two 400 mm wind turbine ventilators of straight vane and curved vane design. The study concluded that at all wind speeds the
straight vane wind turbine ventilators significantly outperformed the curved vane ventilator.  Results of a study Ref. D.M.H. Rashid, N.A. Ahmed, Journal of Wind Engineering 2 (2003) 63-72, showed that a straight / vertical blade design was more efficient at lower wind speeds.