what is passive design?
how passive design help us?
- Passive design utilises natural sources of heating and cooling such as the sun and cooling breezes and it works by appropriately orientating the building on its site and carefully designing the building envelope.
- A well-designed building envelope is able to minimise unwanted heat gain and loss.
Design for
climate:
- Good passive design ensures that the occupants remain thermally comfortable with minimal auxiliary heating or cooling in the climate where they are built.
Orientation:
- Placing the home on its site in the right way to take advantage of climatic features such as sun and cooling breezes.
- Good orientation reduces the need for auxiliary heating and cooling and improves solar access to panels for solar photovoltaics and hot water.
Sealing the
home:
- Sealing the house and increasing insulation levels can create condensation and indoor air quality problems.
Shading:
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Insulation:
- Insulation can let the house warm in winter and cool in summer.
- Insulation can also help with weatherproofing and soundproofing.
- A well-insulated and well-designed home provides year-round comfort, cutting cooling and heating bills by up to half and reducing greenhouse gas emissions.
Thermal
mass:
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Glazing:
- Glazed windows and doors can bring in light and fresh air and offer views that connect interior living spaces with the outdoors.
Skylights:
- Using skylights can improve natural ventilation.
designing sunspaces
Important considerations for sunspace design are:
In very cold climates, double glazing reduces conductive losses through the glass to the outside.
Insulated panels, shades, or blinds are more important for sunspaces than for Trombe walls, as sunspaces are sometimes occupied.
As with Trombe walls, the darker the internal surfaces of the sunspace, the more effectively the thermal mass can store heat during the day.
Do not overpopulate conservatories with vegetation, as foliage can reduce the system's heat capture by significantly shading the floor and wall.
For all climates except those with very cool summers, operable or mechanized windows should be considered at top and bottom. These allow the sun space to avoid overheating by passively venting hot air out the top of the glazing and pulling cool air in through the bottom of the glazing.
In very cold climates, double glazing reduces conductive losses through the glass to the outside.
Insulated panels, shades, or blinds are more important for sunspaces than for Trombe walls, as sunspaces are sometimes occupied.
As with Trombe walls, the darker the internal surfaces of the sunspace, the more effectively the thermal mass can store heat during the day.
Do not overpopulate conservatories with vegetation, as foliage can reduce the system's heat capture by significantly shading the floor and wall.
For all climates except those with very cool summers, operable or mechanized windows should be considered at top and bottom. These allow the sun space to avoid overheating by passively venting hot air out the top of the glazing and pulling cool air in through the bottom of the glazing.
Water Walls:
Instead of using masonry, water can be used as the thermal mass of a Trombe wall or sunspace. Due to convection currents within the water itself, heat is transferred through the entire thermal mass much quicker than a masonry wall that relies solely on conduction. This can be useful when a shorter delay in heat delivery is required. Such systems can not only bring heat into a space, they can be translucent to bring light in as well. When using a water Trombe wall, it is better to seal the air between the glass and wall, to further increase the surface temperature of the wall. |
Solar Chimney:
During hot seasons, a Trombe wall or sunspace with vents through it can be used as a thermosiphon. If vents are placed at the top of the glazing, then air from the room will be pulled out by convection in the air gap between glazing and mass wall. This form of passive ventilation is called a solar chimney. |
Information Source: http://www.yourhome.gov.au/passive-design