Almost half of our electricity bills comes from the energy used to cool down our homes. But don’t despair, there are easy ways we can reduce the load of (and costs of running) air conditioners.
By decreasing the amount of electricity we use (and the fuel used to generate it), we are also cutting down on greenhouse gases and global warming.
Here are some simple tips to help you save your money and our environment.
If you do not have an air-conditioned bedroom:
1. During hot days, keep the doors and windows closed (or at least the curtains drawn) during the day. Do not let in unwanted heat and humidity. Open up the windows to ventilate at night, either naturally or with fans.
2. Install awnings over (or louvres in) windows to provide shade.
3. Plant trees to cool down the house, especially as “sun-breakers” outside windows.
4. Install window shades or mini-blinds. Mini-blinds can reduce solar heat gain by 40%-50%. You can also put solar tinting film on window panes.
5. Have a cold shower or a cold drink before bed to help bring your body temperature down.
6. Delay heat-generating activities like dishwashing and ironing until the cooler evenings.
7. Clean your ceiling fans and table fans to improve speed and efficiency. Dust build-up will slow down the blades and consume more electricity.
If you have an air conditioning unit in your home:
1. Ensure that it is a high-efficiency air conditioner with “energy star” ratings.
2. Switch on the air conditioner only AFTER you have entered the room. Do not keep an air conditioner running if there is nobody in the room.
3. Use the timer to switch off the air conditioner after one or two hours, when the room is sufficiently cool and you are already asleep.
Keep your fan on to ventilate the room. The room should be able to remain cool until morning.
Ceiling fans, on average, use only 75 watts for each hour of continuous use.
In contrast, a central air conditioning unit uses about 3,500 watts per hour, while a medium-sized individual air conditioning unit uses about 900 watts per hour.
4. Keep the thermostat set at 23°C or higher if using ceiling fans. Do not air condition unused rooms.
1. Avoid using the dehumidifier function (indicated by a drop of water on the remote).
This will force the air conditioner to work harder. (The exception is if you set a higher temperature level while using a dehumidifier. This is because drier air often gives an illusion of “feeling” cooler.)
2. To reduce energy wastage, seal all air conditioner ducts so cool air does not leak out.
3. Maintain your air conditioners properly to maximise efficiency. Clean the filters every month if you use it frequently. Dust build-up can reduce airflow by 1% per week.
4. Provide shade for the outside half of your air conditioner if possible. This will increase the unit’s efficiency by 5% to 10%.
5. Consider sharing an air-conditioned sleeping. This will reduce the need to use an air conditioner in more than one room.
Stay cool, use energy and resources wisely and tread gently on the good Earth!
DIY to reduce your electricity bills
The Malaysian Nature Society offers an easy way to create a ‘poor man’s air conditioner’.
Here is a do-it-yourself project that has proven popular with students and room renters.
This is a practical alternative to installing air conditioning units in every room of the house.
The best thing is that it uses items you already have, or items that would otherwise be recycled or discarded.
1. Two (or more) beverage bottles.
2. A table or standing fan.
3. Boxes, stools or books.
4. Trays or plastic takeout containers.
1. Freeze the bottles of water way ahead of time. The cooling effect of half-litre bottles like the ones in the picture will last at least an hour. The bigger the bottle of water, the longer the cooling effect will last.
2. Use the boxes, books or stools to bring the bottles up to the height of the fan blades.
3. Put the bottles in the trays to collect the condensation.
4. Switch the fan on and allow the wind to blow over the frozen water bottles.
In the morning, remember to put the bottles back into the freezer so that you can use them again at night.
Wong Ee Lynn co-ordinates the Green Living Special Interest Group as a volunteer of the Malaysian Nature Society (mns.my).