Recently, we touched the very tip of the iceberg on how the 5 main elements of passive solar design work together to make your home more energy-efficient. While solar energy and energy-efficiency are all relatively modern topics that have gained real momentum in recent years, the science of passive solar build design is not at all new. It’s really simple, yet amazing physics figured out by folks a very long time ago.
Good passive solar design provides optimum thermal comfort with minimal use of artificial heating or cooling – and in some climates, can potentially reduce your usage to almost nothing.
#Tip: Passive homes require you to have a general understanding of how the home ‘works’ with the daily and seasonal climate, like knowing when to open or close windows, and how and when to adjust shading.
Here are some simple ways use passive design in your home.
Design according to climate
Strategies used for ultimate passive design depend on the climate as well as the aspect and attributes of the building site. Australia has 8 main climate zones, each with its own characteristics that dictate the most appropriate design.
The Greater Sydney region is in the Warm Temperate climate zone, for example, with hot to very hot summers and mild winters. There is no one-size-fits-all so you’re best to engage the services of an expert if you’re passionate about getting the best results.
Passive design utilises the sun and cool breezes as natural sources of heating/cooling by orientating the home appropriately and designing the building to minimise unwanted summer heat or heat loss in winter.
In a warm climate, living areas with large banks of windows should ideally face north to take maximum advantage of the sun. Likewise, the direction of breezes are considered, placing windows and doors directly in its path so fresh air can flow freely and easily through.
Direct sun can generate the same amount of heat as a bar heater per square metre of surface. Effective shading reduces temperatures internally, improves comfort and saves on energy.
Because the sun sits higher in summer, the eaves, adjustable shading, external awnings, roller shutters, and leafy plantings provide additional shade, protecting the home until later in the day. Plantation shutters have excellent insulative properties for optimal energy-efficiency.
Permanent shading needs to be properly considered because it will potentially block out the winter sun also.
Passive solar heating & cooling
Most Australian climates require both heating and cooling and it helps to know the specifics of the climate zone you’re in to achieve this.
Consult an expert to discuss how best to capture and retain the warmth of the winter sun, while allowing the built-up heat of the summer sun to escape.
Sealing your home and eliminating drafts is one of the simplest ways to maintain internal temperatures and reduce energy usage, with air leaks accounting for 15–25% of winter heat loss. The more extreme your winter, the more beneficial sealing is.
Insulation acts as a barrier and is an essential element for keeping your home warm in winter and cool in summer. A well-designed and insulated home provides year-round comfort, reducing heating and cooling bills by up to half (heating/cooling accounts for around 40% of household energy consumption).
Up to 40% of a home’s heating energy can be lost and 87% heat gained through improper glazing.
Windows and doors provide natural light, fresh air and connect interior spaces with the outdoors. However, they can be a major source of unwanted heat gain/loss, making your insulation efforts null and void.
This can be largely overcome with the right glazing – double glazed windows are excellent at reducing energy consumption considerably.
Skylights can make a major contribution to energy efficiency, comfort, and, research shows, to the value of your home. They are an excellent source of natural light, perhaps generating more than three times the light of a vertical window.
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