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Published on April 15, 2008

Owner Wichart Manachaimongkol has saved 10.38 per cent on energy consumption, or 863 units of electricity per year, after renovating the building for energy efficiency.

The refurbishment not only saves money (about Bt3,020.50 per year based on a cost of Bt3.50 per unit), but also creates better living conditions and a healthier environment by reducing greenhouse-gas emissions.

One principle that must be accepted in such conversions, however, is that upfront investment is often steep but shows generous returns over time. The core ideas are stopping the incursion of hot air into living spaces, changing habits and using energy-saving electrical appliances.

Installing aluminium foil and fibreglass insulation is the most efficient way to cut electricity bills, because this can prevent a build-up of heat. Where the insulation should be installed is really a matter of the size of the home-owner's budget.

Those on a very tight budget should perhaps limit the installation of fibreglass insulation to the attic, because that is directly heated by the sun. For those who can afford it, insulation should be installed not only in the attic, but also in ceilings and walls, particularly in rooms with air-conditioning, because it can prevent heat flow and reduce cooling costs.

Importantly, insulation at least 3 inches thick is recommended for hot countries like Thailand. Layers of lesser thickness are not as energy-efficient.

Three-inch-thick insulation costs about Bt300 per square metre, while the installation cost is Bt50 to Bt100 a square metre. Preparing the attic for installation may cost an additional Bt30 to Bt50 per square metre.

Many home-owners overlook trees as a means of blocking sunlight and providing moisture. In fact, a single large tree can produce the cooling effect of 10 room-sized air-conditioners operating 20 hours a day.

Stairs and hallways gather stale air, because of little or no ventilation. Installing an awning window above a flight of stairs can bring in fresh air. Glass blocks are also recommended, to admit natural light to dark stairways, so that there is no longer a need to switch on lights during daylight hours.

Remove louvre windows from air-conditioned rooms, because such windows leak air, and the air-conditioning must then consume more energy to maintain the set temperature.

Rooms that are painted in light colours accumulate less heat than do dark rooms. Moreover, light-coloured rooms reduce power bills for electric lighting.

The most important living habit to change is using electrical power during the peak period, from 9am to 10pm. This is when electricity costs the most.

Turning a fan on when air-conditioning has just started up can accelerate the build-up of cool air and help save electricity, and don't forget to set the temperature of air-conditioning to start from 25 degrees Celsius.

Setting the air-conditioning timer to turn off about 30 minutes before you wake up can also save energy.

Turn off both computers and monitors when they are not being used and use energy-efficient appliances.

Those appliances with label No 5 have already been proven to use less power than those without a label rating or with a lower number.

Replace incandescent bulbs around the house with compact fluorescent lamps. These may be three or four times more expensive, but they last up to five times longer and use 80-per-cent less electricity.

Bulbs with the highest lumen rating at the lowest wattage consume less power but give better brightness. Wattage is the power needed to make a bulb work, while lumens measure brightness.

Oranan Paweewun

The Nation