Solar Passive design can not only minimise your impact on the environment, but can also reduce the impact on your back pocket. Solar Passive Design principles can be easily incorporated into your home design without any additional construction costs, with the added benefit of reducing the energy use of your home over its lifetime. If you have no idea where to begin, you are not alone! Read on for some ideas that can provide you with a good starting point for your solar passive design.
Location is critical when it comes to cooling breezes. In the warmer summer months, these breezes provide you with natural air conditioning to flush out hot air and cool your home. In Perth, smaller operable windows located on the south-west orientation of the house are ideal, as they allow these cooler south-west summer breezes into the house. Ideally, these cool breezes will then travel through the home and out the windows located on the opposite face of the building, the northern orientation. When rooms can only have windows located on one wall, two windows can be used side by side, widely spaced to provide the breeze with an entry and exit path.
A breeze path can be further enhanced through the inclusion of correctly designed and positioned wing walls. Wing walls work by stopping the wind in its path, capturing it, and then directing it into the designated window opening. A wing wall is simply a wall positioned beside the window, running perpendicular to it so that it can trap the wind in its path and enhances the natural cooling directed through the home.
Glazing & Shading
Glazing brings in light, fresh air and winter heating. However, along with the winter heating, comes the summer heat. Up to 87% of the homes heat is gained through glazing and up to 40% of the homes heating can be lost through this same glazing. With today’s technologies, there are a wide variety of different glazing types, with each performing slightly differently. This provides you with the opportunity to use the correct glazing type for the windows specific job. Glazing types are now so advanced that they can be designed to allow the suns long wave heat waves to enter the house, but once they become short heat waves inside the house, they then become trapped and cannot exit through the same glazing, therefore providing a great function of capturing winter heat.
Before you look at upgrading your glazing, you want to make sure that your shading is correct. There is little point spending any additional money on improved glazing if your basic design principles have not been considered. Shading your house greatly reduces the inside summer temperature, improving the comfort levels without any auxiliary cooling.
Along with correct shading, insulation will help prevent unwanted heat from entering the house. Insulation acts as a barrier to heat flow, preventing the hot air in summer entering into the house and the warm air in winter from escaping the house. Insulation comes in many different types and forms, with different varieties working better for different applications, depending on the location and desired result.
Air leakage is another simple passive design solution to consider when building your own home. Air leakage can account for up to 20% of winter heat loss, along with a considerable amount of cool air lost in the summer months. If air leakage is minimised, ventilation through desired openings can ensure the solar passive principles incorporated into the design work to their maximum ability.
Thermal mass is the ability of a material to absorb and store heat energy. High density materials such as concrete, bricks, stone and even tiles require a large amount of energy to change their overall temperature. Therefore, they are fantastic materials to use for your home, when utilised in the right location. The key being the right location. badly placed thermal mass can worsen the extremes of the climate by storing and radiating heat in summer and the opposite in winter. Good thermal design will moderate the indoor air temperature throughout all seasons of the year. In winter, thermal mass releases the heat stored from the direct sunlight during the day into the cooler air inside the house at night. In summer, the thermal mass should be shaded from direct sunlight. This allows the thermal mass to absorb internal energy from the heat inside the house during the day. The cool night breeze then passes over the thermal mass, drawing out any day time stored energy which then, in return, cools the overall internal temperature for the day to come.
“An open floor plan can be utilised to enhance all of the above passive solar systems, for both heating and cooling. A well designed home, combined with these principles can provide you with a modern home which will not only benefit your wallet.”Janik Dalecki, Building Designer
As you can see, location is key when it comes to solar passive design. Not only the location of the block and the position of the home on the block, but the location of every item within the design- from the individual rooms down to each individual window. For the best result, a passive home needs an active user; people with a basic understanding of how the home works with the daily and seasonal climate, such as when to open or close windows. This is where using these basic, easy to implement passive design solutions can provide a better result than some of the more complex, expensive solutions that not only cost you extra, but require more work to operate.
Article by Janik Dalecki