It seems to me that out here in western Sydney the summers are getting hotter. In the last two years we have had several days over 45°C and more than I care to think about over 40°C. Along with this has been the feeling that levels of heat that never used to bother me are now causing me some trouble. I mentioned this to my doctor and she made some comment that sounded like it was because I was getting bold, but I may have misunderstood.
One way of dealing with this, and it certainly is the method of choice for some of our neighbours, is to run the air-con 24/7. This is expensive and there has been talk of power issues on the really hot summer days and the possibility of blackouts. We have our own standalone power system, but when I was designing it the theory was that because the air-con is a major current draw and is only used for a few hours on the couple of hottest days of the year (ha ha), it would remain grid connected. Anyway, so much for that idea!
So what is the answer? A cool retreat!
A cool retreat is an area of your dwelling which has been set up to remain as cool as possible during heat wave conditions and which you can…….. retreat to. The area may be set up specifically to function as a cool retreat during construction or, as ours was, an area retrofitted into our standard 1970’s era dwelling. To work out where we were going to put our cool retreat we had to look at our house and identify the best location.
The criteria we used to identify where our cool retreat was going to be were –
- The area was, or could be insulated and/or protected from high outdoor temperatures,
- It could be isolated from the rest of the house,
- It had existing mechanical cooling assistance, and
- There was sufficient area and facilities to be comfortably habitable for extended periods.
After looking closely at all rooms of the house we decided our cool refuge would be our Livingroom/kitchen/dining room area. We have a comparatively small house (120m2) and these three rooms add up to a total of about 30 square metres (or one quarter of the house floor area).
So, to look at the criteria and how this area fitted them more closely -
1. Insulation/Protection from Outside Iemperatures
The whole ceiling is insulated with fibreglass batts, which was done the year after we moved in and they still seem to be working well. There is no wall insulation, much as I have tried to organise something, it would require electrical rewiring as the current wiring is rated for open air only (heat could build up and cause a fire if we insulated the wiring).
Probably 15 to 20% of this part of the roof is also covered with solar panels which will provide a bit of sun protection.
Our house is oriented so that the front faces a little south of east, and the back faces a little north of west. Due to the greater sun arc in summer, the nominally southern wall of the house gets a blast of afternoon sun, which would add to the heat load of the lounge and dining room, but the garage is along that wall so most of it is protected from direct sunlight.
Our biggest heat gain has always been from the west, and since the early days things would become uncomfortable from about 1:00pm onward, so this is where a large part of our efforts to provide protection to our cool refuge were expended. We have a deck built on the back of the house, protecting the kitchen and dining room western wall. The roofing is clear but we cover it in a double layer of 90% shade cloth for the summer and it provides excellent shade.
We also put in bamboo blinds on the front of the deck so that the wall is still protected as the sun sinks lower in the west and the direct sunlight can get under the deck roof and hit the walls and windows. Due to the slightly off kilter orientation of the house there is an open spot between the deck and the garage which allows sun light and heat to hit the dining room window and part of the wall. To cover this area I installed another bamboo blind on the fascia board at the outside of the eaves, which now provides shade for that part of the dining room window and wall.
The windows are obviously an area where the outside heat can be transmitted into our cool room. The lounge room window has a roll down shutter for insulation and we use thin (1 to 2 cm) sheets of polystyrene which fit inside the window frame and act as insulation against the heat.
2. Isolation from the Rest of the House
There is an archway leading from the lounge room into the hallway and the front door, an open doorway leading from the kitchen into the same area and an open doorway leading from the kitchen into the laundry/back room area.
In the lounge room arch and kitchen door way to the hall we have installed concertina style doors, which allow the area to shut off fairly well, but the laundry/kitchen doorway was still open so as a low cost fix we have attached a blanket to cover the doorway. We can still get in and out of the laundry but the blanket is very effective in keeping the cool air within our cool refuge.
3. Existing Cooling
The only air conditioning in the house is a split system on the outside wall of the kitchen dining room, which means we can cook and eat in relative comfort. We also have a ceiling fan in the lounge room to help keep the air moving and increase comfort. As we have put in more and more protection against the heat for our cool refuge, we have found that when we get those scorching days we don’t need to put the air-con on until 4:00pm or sometimes even later.
4. Facilities for Comfortable Habitation
In the kitchen area we have……the kitchen! So we have facilities for cooking our food without leaving the cool refuge. This is good, because we don’t need to leave the refuge to cook, but bad because it can act as a source of heat into the cool refuge. Generally the air-con can take care of that problem but it is something to think about. The fridge is also a small source of heat into the cool refuge.
The dining room provides a place to eat but also a place to set our computers up in the cool (to do things like writing this article) or to play games etc.
The lounge room has the TV, music machine and bookshelves etc as such rooms tend to do, but the lounge itself also folds out into a bed so that we can sleep in our cool refuge if required.
In general terms we have found the cool refuge concept to work fairly well for us. It has considerably reduced our reliance on air conditioning as our primary means of cooling, which has also reduced our electricity bills and increased our level of resilience in the event of blackouts, which have been threatened but not occurred in our area at least (so far!)
If you want more details on the “cool retreat” concept or other means of coping with heat wave conditions, the document “A framework for adaptation of Australian households to heat waves” produced by the National Climate Change Adaption Research Facility (Part of the University of South Australia) is worth a look.
