Outdoor shading is an essential part of a home’s energy saving strategy and awnings have long been considered a great solution. The role of an awning is to provide the flexibility to regulate the amount of solar energy that reaches the facade, especially glass, of your home. Awnings reduce the ability for solar energy to be converted to radiant heat in your home benefitting your living space with comfortable levels of visual light and more flexibility to naturally ventilate your home.
In Winter, an awning is best utilised to reduce visual light transmission when required and is retracted when you want the solar energy to heat your house.
In Summer, the awning shields your façade from solar energy reducing visual light combined with massively reducing solar load, which converts to radiant heat on contact with any exposed surface. The passive control of solar energy with external awnings saves you money and saves the environment. Reduced reliance on mechanical equipment costs such as air conditioning and heating ultimately reduces your energy bills and is less demanding of utility infrastructure and natural resources.
- Direct radiation from the sun is the most important component shading has to address. Reflected light is strongly influenced by the reflecting surface. For example grass will reflect 20 – 30% and snow more than 70%. Single pane glass reflects only less than 5%.
- External shading devices are the most effective in reducing heat gains because they intercept and dissipate most of the heat in solar radiation before it reaches the building’s surface. This differs to internal shading where the sun’s rays hit the building or window and then traps the heat in. This heat is hard to remove.
- With a markilux awning it’s possible to achieve a 95% reduction in solar thermal energy radiation, however the average awning should block out about 80% of the heat load.
- Recent statistics by the NSW Government estimate that the average Australian home spends $265 a year on airconditioning. By installing adequate outdoor shading and appropriate awnings you can eliminate the use of air conditioning all together or reduce it by up to 75%
- It is estimated that adequate external window coverings can reduce carbon pollution by 200 kgs each year.
TIPS WHEN CHOOSING AN ENERGY SAVING AWNING
The type of awning that you choose to install is also crucial to the savings and energy saving outcome. The traditional image of an awning (ie: a scalloped piece of cloth and bit of metal!) has been replaced by modern outdoor shading solutions. The modern markilux awning incorporates energy saving ability but also design, image and aesthetics, adapting themselves ideally to their surroundings and giving sun protection of
the highest quality.
- TYPE: When it comes to energy savings, there is no real difference in retractable or fixed awnings during peak Summer months, as they are both effective at blocking sunlight and reducing energy usage. During the Winter however, some homeowners may prefer retractable or adjustable awnings because they can be retracted or adjusted to expose more of the window glass and thus let more light and heat in.
- SIZE: Proper sizing is important to optimise for blocking the summer sun and allowing the winter sun to shine through for passive solar heating.
- POSITION: The orientation of the window to the sun as well as your latitude, affect how far away the awning must project from the house wall. In Australia, awnings should be fitted to north, east and west facing windows and are more effective for blocking out morning and afternoon rays than internal blinds, curtains or shutters. Window awnings can reduce solar heat gain in the summer by approximately 65% on south-facing windows and 77% on west and north-facing windows.
- CIRCULATION: Awnings require ventilation to keep hot air from becoming trapped around the window. Grommets (eyelets) or other openings along the tops and sides of an awning can provide ventilation. The awning may also open to the sides or top to vent hot air. An awning can greatly assist in the ability to naturally ventilate your living space improving air quality.
- MATERIAL: Choose fabrics that have a minimum 98%UV and 50+SPF factor. Lighter coloured fabrics will be cooler and lighter underneath and darker coloured fabrics absorb the heat more, so can be warmer and darker under the awning. Quality is key. The fabric should be water resistant, durable, tear proof and not susceptible to rot, quick drying, resistant to heat, cold and other environmental influences.
This article has been provided to Your Future Home by Tess from The Guides on behalf of Markilux. For information on Markilux products visit www.markilux.com.au