Energy Diet

Home Is Where the Heart Is

Just as I started the 360° Energy Diet last week, a heat wave hits us for 4 days. Johannesburg experienced its hottest recorded temperatures, ever, for the month of October – 33.4°C (92.1°F). While it’s great for a tan, it’s not great for energy bills as our air conditioner was used for 2-3 hours every evening to bring the ambient temperature in the bedrooms down to 20°C (68°F).

During the course of the diet, points are allocated in 6 main categories: home, food, transportation, waste disposal & recycling, water use and what you buy. My initial score was 235 points with the best category being home (60 points) and the worst category being waste disposal & recycling (25 points). There certainly is room for improvement in all six categories, but there are items on the list I just won’t be able to tick off, at least for the next few years, i.e. use public transport. Each week for the next 6 weeks, I will comment on each category in more detail and how I have changed my habits, or plan to change them.

Category 1 – Home

Even though this is the highest scoring category, I believe I can make a big impact on the unticked item as well. Before starting the diet, I’d already identified that the halogen down lights had a high energy consumption but the costs to replace every halogen is going to cost about R9400 ($1175) for 47 LED’s. Subsequent investigation and advice from friends is that although LED’s are more efficient, they also get extremely hot at the back of the globe so it requires air circulation to keep them cool. The plan is to use CFL’s in the lounge and kitchen as they are mounted in concrete slab and to use LED’s in the bedrooms and bathrooms where there is more space in the roof.

Having moved into a newly built home in 2007, the geyser and surrounding pipes were insulated together with the entire ceilings in the upstairs rooms. I must say that it works well in winter to keep the warm air from escaping, but it doesn’t work that well in summer. As a result the geyser was turned down to the lowest possible setting of 50°C (122°F) and even that is too hot. Another installation during the construction phase was to have a timer installed at the distribution board to regulate the times the geyser is working.

Polystyrene insulation built into the concrete slab

In my previous post I mentioned the polystyrene boards placed in the concrete slab, which does wonders in keeping the floor temperature regulated, and thereby eliminating the need to underfloor heating. A photo during construction is shown (left).

One advantage of living in South Africa is the weather – winter are dry and last about 3 months, with daytime temperatures getting as high as 20°C (68°F). Cold snaps last a few weeks at a time, but it’s seldom below 10°C (50°F) for long. That means we get to hang the washing outside and let the sun do the hard work. One of the disadvantages of living in South Africa is the lack of double insulation in buildings, resulting in wasted energy in heating and cooling various rooms.

Next week I’ll be discussing one of favorite topics… food (category 2)