Do our houses handle the heat?
It’s one thing for us to explain the theory behind the design and thermal performance of our houses, but it is much more interesting to hear about the reality, directly from the people living in them. Here’s some feedback following the mid-January heat wave when the maximum temps were as follows: Tue 14 – 37.6, Wed 15 – 40.2, Thu 16 – 40.1, Fri 17 – 39.7, Sat 18 – 40.0 (see January climate data from BOM here.)
New house in Ainslie finished April 2013:
”Our house is fairing very well in the heat. It had been shut up since Tues (we escaped to Jervis Bay for a few days) and when we returned Fri evening it was warm but not unpleasant. The hottest room was 30 – the office with all the electronic gismos pumping out heat. The bathroom was 24.5. We had accidentally left two western blinds up/open and this would have made a large difference over four hot days. Once we refreshed the house last night we closed it up again today about 10.30. The Nest in the hallway reads 26.5 and the bathroom 23.6. The ceiling fans are on 3 [the lowest setting] and we haven’t thought to dig out the old pedestal fans. There are SOOO many great qualities about this house that we are grateful to Jigsaw for.”
New house in Wright finished Nov 2013:
”We’re doing well and so is the house and neither it nor us have melted!
We reckon the ‘weak’ point is the west side (as we knew would be) and it’s really interesting to just observe how it performs with little ‘help’ in terms of blinds/shutters or awnings or garden microclimate.
I’ve attached the stats we collected since Tuesday…hope they give you some insight into how the 8.5 star house goes.”
[Temps and comments show that our clients – a family of four – were still feeling very comfy with ceiling fans on, when the indoor air temp got to 27-28 degrees. It was only on the Thursday afternoon at 5pm when the indoor air temp reached 30 that they started to feel uncomfortable].
”As you can see, we only blasted it once with the AC in the afternoon on Thursday and I think that’s partly because we could only get it back down to 25 after the warm Wednesday night and the slab gaining temp over the days.” [The 3kW split AC system referred to was primarily installed as the only form of active heating for this house]
”We’re off camping tomorrow till next Friday so we’ll miss the last 2 days of the heat!”
New house in O’Connor finished Nov 2013:
”Our house performed exceptionally well in Canberra’s recent heat wave. The highest internal temperature was 28.6 degrees on a day that got to 39.8 outside with a total of 5 hours over 35 degrees. This was also one of five days in a row over 37 degrees. The ceiling fans made the rooms feel about 2 degrees less and ~26 maximum felt very comfortable – didn’t once have to offer visitors buckets of water for feet soaking as we did at our old house a few summers ago. We did the time-honoured trick of opening up the house once the external temperature was lower than the inside temperature and closing up as it rose again.”
Reno/Extension in Narrabundah finished November 2013:
”I’ve been trying to open up the house as early as possible (getting up at 6am!) to cool it down. I’ve been getting it down to the low 20s by the time I leave for work at 7.30ish. According to the thermometer I have, it’s been about 28 degrees when I get home – but I have to take into account the fact that I don’t have proper blinds yet…! In any case, it’s actually been quite comfortable with just the fans in the evenings.”
Our new houses have insulated concrete slabs (underside and edge) because they are designed to soak up and re-radiate the sun’s heat over Canberra’s winter (when we use the most energy in our climate). Considering this, we are really pleased to report that our houses are also coping very well over summer without the need for active cooling systems (only ceiling fans). This is because we minimise any sun strike to the slab over summer by orienting the house, and positioning windows, very carefully. We optimise the eave width to the north to prevent the summer sun hitting the slab and advise clients about the importance of shading any eastern or western windows they may have. Many people believe that lightweight buildings, or houses with earth-coupled thermal mass (not separated from the ground by insulation), are the only ways to make houses that cope with hot weather. In Canberra, where we need to cope with both winter and summer extremes, we think we have found an effective balance!