Homes and heatwaves

MEFL’s Senior Consultant Jon Morgan presented at the Ecocity World Summit 2017 recently on the topic of “Australian Houses and Heatwaves”.

Jon’s presentation focused on the increasing severity of heatwaves in Australia, the health impacts of heatwaves and how buildings can be designed to mitigate the impacts.

Heatwave impacts

An indication of the impact is the January 2009 heatwave in Melbourne resulted in an extra 7000 ambulance dispatches, almost 2000 after-hours doctor visits, over 700 hospital emergency patients and 374 excess deaths (above what would normally be expected for a similar time of year without a heatwave).

Health risks associated with heatwaves will be experienced across a diverse range of housing types from detached dwellings to high-rise buildings, both new and old buildings, public and privately owned, owner-occupiers and renters.  In addition, the health impacts will be felt more strongly by the more vulnerable people in our community, including aged and infirm.

Solutions

Whilst air-conditioning may appear to be an obvious solution that many people will turn to for heat relief, it does have its own problems, including causing power demand ‘spikes’ during heatwaves, affordability problems for low-income residents and urban heat impacts.

Jon’s presentation examined a range of building-design elements that can help keep indoor temperatures comfortable during heatwaves, including:
•    Window size, orientation and thermal properties
•    Ventilation and infiltration (while ventilation is controlled by the building occupants, infiltration refers to air leaks through cracks etc.)
•    Wall, roof and floor insulation
•    Thermal mass
•    Outdoor landscaping

Jon presented research findings that identify windows, infiltration and thermal mass as being the key factors that affect a building’s ability to protect its inhabitants from heatwaves. These findings will be of interest to designers and planners, asset managers and of course consumers.

One thought on “Homes and heatwaves

  1. Thanks for this subject.
    Its vitally important to retrofit aluminium foil reflective insulation products to underside of all residential roofs, either tile or metal.
    Downward facing foil surfaces, with 50-100mm airspaces, will re-radiate or emit approx 3% of all the incoming radiation.
    The science of aluminium foil has been known since 1953 when the first roll of sisalation was sold in Australia in Melbourne by my father Ted Renouf, working for Sisalkraft.

    Foil is more efficient in stopping intense radiation than endlessly thick bulk insulation. Bulk for winter, foil for summer.

    The insulation test method for bulk is a 4 hour duration at 23degC “mean”.
    This is wrong for long hot summers of 50-70 degC roof spaces.

    I am a foil insulation manufacturer in Cheltenham since 1991.

    I know my subject very well.

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