Summer’s here and the temperature is frequently topping 40°C. I usually go around the outside of the house and compare temperatures in full sun and in shade. This year I’ve made a video of most of my findings. Some might surprise you – they always do me! The take home lesson from all this is that shade is good, full sun is bad. It’s that easy! The inside of the house averages 24°C throughout the Summer with minimal input from our evaporative air conditioning. We do have a reverse cycle aircon that came with the house. That gets used for an hour or so here and there when Jelina gets home late from Uni on stinking hot days. She deserves a little coolness at the end of the train trip home. Apart from that, it’s ceiling fans and judicious cooling of the house at night time by venting in the cooler air through the evaporative system on the vent setting
Bubble wrap can be easily applied to windows as insulation. A while ago, I wrote a post called ‘Bubble Wrap Insulation‘. That post was aimed at keeping the Winter cold out and our precious heat in but as its been so hot here lately, I thought I’d measure the difference it made on the windows in Summer. The digital weather station with today’s temperatures. The pic above shows the weather station in the lounge. You can see the inside and outside temperatures. The digital ‘gun’ type hand held spot thermometer that I used to take the other measurements agrees with this, within a few 1/10ths of a degree. The bubble wrap pulled back so that I could get a comparison. To prepare the window, I pulled the bubble wrap off of one half of a window and left the other half attached. Then I left it for half an hour before measuring. The window wasn’t in direct sunshine,
Over the last week, interrupted by periods of bad health, and with Marlon’s erstwhile assistance, I’ve put up a shadehouse that covers most of the northern end of the house. This is the end that usually gets blasted all day by the summer sun, so shading it has been on our to-do list for a while. We were lucky enough to get some cheap building materials, so went ahead and did it. It’s already making a difference. The other hot day I measured 46° on the exposed brickwork but only 36° on the bricks under shade. Thats a 10° difference! The best way to stop something getting hot in the sun is, of course, to block the sun and prevent the heat getting to it. While ambient air temps and humidity can offset the effectiveness if this technique, it’s still a pretty effective and simple technique to keeping the house cooler.
I noticed something about the temperatures yesterday, so got out some thermometers and checked the situation. The temperature inside the house was 24 °C, outside was 34°C. The interesting thing was that the temperature of the window glass on the western side of the house was almost 45°C! That was a lot of heat pumping into the house. I dropped the external blind and after 10 minutes checked the temperature of the glass and it had dropped to 37°C. Half an hour later I checked again and the temp of the window glass was down to 34°C, the same temperature as outside. This showed me much heat is radiated through uncovered windows in summer. Imagine how much is pumped in through those huge windows in many commercial, or some newer residences. How much power is used by airconditioning to make temperatures comfortable? External shading is essential for reducing out energy use.
I had an interesting ‘how to’ delivered to my email this morning. ’ 10 Tips For Drying Clothes Outdoors On A Clothes Line’. I found it interesting, not because I don’t know how to do it, but the fact that there are probably people out there who have never done it. People in modern, technological, wealthy places who until recently would have just thrown their clothes in the dryer or just taken them to laundromat. Its a sign of the age that’s just passing, an age when we in the ‘developed’ world places didnt need to worry about energy use, supplies, cost or its contribution to climate change. It’s the type of ‘how to’ that we will see more of. Here’s the link – http://thehomesteadsurvival.com/10-tips-for-drying-clothes-outdoors-on-a-clothes-line/