Allan Street, Brunswick: The Passive & Active Energy-Efficient Systems Implemented
Passive Systems
For this project, just as in all of our projects, a range of passive solar design practices were applied to the scheme. When considered in the initial design phase, they can be quite straightforward. The large expanse of glazing is facing north toward the sun. An overhang at 63 degrees shades the glazing to let the winter sun in while blocking out summer sun. A pergola structure snakes around the side of the building. It becomes larger on the western side to shade lower western sun. The form of the sun shading reflects how you’d naturally use the space at different times of the day. Where the overhang widens, a shadier, cool spot is created that can be used in warmer weather.
Above: The North facing glazing screen by the pergola structure
All the walls and ceiling have a high level of insulation and a concrete slab acts as a thermal mass absorbing the warmth of the sun. Cross-ventilation through the space, ceiling fans and a bank of high operable louvres that work as a thermal chimney, assist air movement and the expulsion of warm air, in turn enhancing comfort levels.
Above: windows and doors placed to allow cross ventilation and a operable windows working as a thermal chimney.
Compartmentalisation
An additional element to enhance the efficiency of a home is compartmentalisation. When you have an old house and a new extension, it’s easy to make the new section thermally function well. Though the old house is often quite difficult to deal with. You can add insulation in ceilings and walls, but unless you’re re-plastering, it’s difficult and expensive to do so throughout. Having doors that separate the old and new areas of the house is a simple way to separate spaces, enhancing thermal performance. Whether it’s cooling when air conditioning is on in the main living areas, for heating, or sometimes it’s even beneficial for noise.
Active Systems
Micro inverter PV cells were installed which are more adaptable to batteries as well as adding more panels at a later stage. All solar panel systems installed in our projects are battery adaptable. There’s a common issue of heating and cooling in house extensions and every client has a different view of how much they want to heat or cool their home. Some people prefer not to heat bedrooms while some do. In this project, there were three existing split reversible air conditioners. With consideration to budget, these were added to rather than discarded. Several rooms have a reverse-cycle air conditioner which, intuitively sounds like a terrible thing to do environmentally; however, their PV electricity generation on the roof would mean that during the day, they’re probably covering the electricity. The intention is also that due to do the application of passive solar design principles, additional insulation etc. you’d hope they don’t have to use the split systems too often. In-slab hydronic heating was installed in the kitchen, dining, living room and study areas.
Selecting efficient active systems for a home is really about identifying how the occupants want to live, and also working with what’s already there, not just discarding it and applying a whole new technology, especially when working to a tight budget.