Australian Passive Solar Home

So what do you do if it’s a 36 deg C day and the power is going to be off from 8.30am until 4pm? Well, if you’re in a well-designed passive solar house, you don’t do anything.

That was my story yesterday – a long scheduled power cut for line maintenance, and a hot day.

But from a comfort and health perspective, having no power simply didn’t matter.

• There was still plenty of light as the large windows let in natural light, that at this time of year is diffused by the eave shading and net curtains. No need at all for artificial light.
• Despite it being 36 deg C outside, inside it peaked at 24 deg C – there’s no need to run air conditioning in this weather.
• Although the relative humidity was 11 per cent outside, inside it stayed around 50 per cent, the indoor plants and cooler temperatures doing their stuff.
• Carbon dioxide (CO2) didn’t exceed 600ppm – there was no change to that figure without power, as the fresh airflow doesn’t need a mechanical ventilator.

In short, the only change was that the ceiling fans didn’t work, and at 24 deg C inside air temperature, and with thermal mass around you that was 3 deg C cooler than that, they were not needed anyway.