Passive Design

Passive Design at Taman Petanu

Basic principles of passive cooling design for tropical climates

• • Site for exposure to breezes and shading all year

  • Use of light colored roofs and walls to reflect more solar radiation and reduce heat gain

  • Elevate buildings to permit airflow beneath floors & consider high or raked ceilings

  • Provide shaded outdoor living areas

  • Design and build for cyclonic conditions

  • Use lightweight construction include thermal mass where diurnal range is significant

  • Maximize external wall areas (plans ideally one room deep) to encourage movement of breezes through the building (cross ventilation)

  • Use evaporative cooling or ceiling fans

  • Allow passive solar access in cooler months only

  • Shade all east and west walls year round

  • Use reflective and bulk insulation (especially if the house is air-conditioned) and vapor barriers

  • Orientation for exposure to cooling breezes

  • Increase natural ventilation by reducing barriers to air paths through the building

  • Provide paths for warm air to exit the building

  • Floor plan zoning to maximise comfort for daytime activities and sleeping comfort

  • Appropriate windows and glazing to minimise unwanted heat gains and maximise ventilation (less windows, more open air flow is better)

• • Effective shading (including planting shading species in strategic locations)

  • Adequate levels of appropriate insulation

  • Maximise the indoor/outdoor relationship and provide appropriate screened, shaded, rain protected outdoor living spaces

  • Maximise convective ventilation with high-level windows, ceiling and roof space vents

  • Design ceilings and furnishing positions for optimum efficiency of fans, cool breezes and convective ventilation

  • Locate mechanically cooled rooms in thermally protected areas

  • Adjust eve overhangs to suit the particular micro-climate

  • Include evaporative cooling and water features

Basic principles of passive design for humidity control

• • High humidity levels limit the body’s ability to lose heat by evaporation of perspiration. Sleeping comfort is a significant issue – especially during periods of high humidity.

  • Design eaves and shading to permanently exclude solar access to rooms

  • Consider shading the whole building with a fly roof

  • Maximize shaded external wall areas and exposure to (and funneling of) cooling breezes through the building

  • Use single room depths with maximum shaded openings to enhance cross ventilation and heat removal

  • Design unobstructed cross ventilation paths

  • Provide hot air ventilation at ceiling level for all rooms with spinnaways, shaded opening clerestorey windows or ridge vents

  • Shade outdoor areas around the house with planting and shade structures to lower ground temperatures

  • Use insulation solutions that minimise heat gain during the day and maximise heat loss at night. Advanced reflective insulation systems and reflective air spaces can be effective

  • Choose windows with maximum opening areas (louvres or casement) and avoid fixed glass panels

  • Include ceiling fans to create air movement during still periods

  • Consider using whole of house fans with smart switching to draw cooler outside air into the house at night when there is no breeze

  • Use low thermal mass construction generally. (Note: high mass construction can be beneficial in innovative, well considered design solutions).

  • Use planting design to funnel cooling breezes and filter strong winds

For more information on passive design see: www.AlamSanti.com