When the temoerature’s over 40°C for days on a row, a well built system of shade is necessary. It’s good to make that shade out of edible plants and porous surfaces.
The view in the pic above is from our front door, looking straight to the West where the afternoon sun is now down at about eye level.
A barrier of trees and other plants can slash a surprising amount of the incoming heat. They cool the air it picks up the moisture they transpire . Add to that the fact that all of ours are edible and you get a year round bonus too!
When we first lived here, the Sun blazed down on the unprotected Western side of the house and the only way to live inside was with all the windows blacked out with multiple layers of curtains and the lights and the reverse cycle air conditioner on full. It was dark, stifling and depressing.
We’ve used that air-conditioner only once this year, despite daytime temperatures reaching over 50°C. The inside temperature has yet to break the 29°C mark.
So, beside the plants, how do we keep cool?
We have ceing fans in the main rooms like the lounge and bedrooms. They move the air around, making it far more comfortable and breathable inside. The air they move evaporates the sweat from your skin, reducing skin temperature and making things a whole lot more comfortable. This means that the critical ‘Turn on the aircon!’ temperature is 28°C instead of the 24 °C that it was. Looking back, we wish that we had purchased and installed them in every room.
To be honest though, our main defence is to use the evaporative aircon sparingly. Once the night time temperature drops 2 degrees below that inside, we put the evaporative aircon on in its ‘vent’ mode. That is the most efficient and effective way to distribute the cooler outside air throughout the house. All the windows and doors are kept wide open.
We used to just open them and let the air infiltrate through the openings, but that is very slow and not very effective. The 450W aircon motor is our best compromise.
On days over 34°C, we run this aircon as needed during the day.
We also dump the air from the house into the roof through three low energy exhaust fans (total of 14W) at the beginning of the process.
All of this means that we are a far cry from the stifling, dark days of three years ago.
We aim to get the inside temperature down into to the 22 – 24°C range before the Sun is up and temperatures begin to rise again. Then we close it all up and enjoy the day.
Our windows are of that terrible, old fashioned ‘sash’ design, where one half will pull up or down. These are great for winter but are terrible in Summer because only half of the surface area is available to the cool air.
Each of the glass panels on the Western side of the house has a bubble wrap lining on the inside. That can drop the inside window temperature around two degrees, while still letting light in. It works the other way in Winter too, keeping the heat in. All the doors are well sealed, using door stops of various sorts as well as that gap sealing tape. A small gap on the hot, windward side of the house can let a surprising amount of air in or out.
In previous years, we used pull-down, outside, blinds of shadecloth material to stop the Sun from hitting the window glass (that’s the most effective method of keeping the temperature down). This year, though, that has proven unnecessary on most windows because the vines and climbing plants have now become big enough to grow along the wire trellis and shade the house.
We have a Yellow Passionfruit and Hops well established and Kiwifruit coming along nicely for next year.
Interestingly, the vines don’t have to be deciduous to help in Winter as most pundits say but thas maybe for another article.