Being simple is being sensible!

Growing trees around your home reduces heat gain a great deal. Why pay so much for fans and air conditioning? Be trendy. Grow trees around your home and reduce your bill.

Be wise in choosing the type of trees. Large leaf types such as jack fruit is a bad choice, while small leaf types such as Kohomba and Tamarind are preferred. They have minimal effect in clogging drains or rainwater drainage systems, and also shed relatively less leaves which contribute to making the place untidy.


Use air conditioning moderately. Keep the places cool, not freezing cold. The ideal temperature is 26oC. for hot and humid Sri Lanka.

An air conditioner is a refrigerator sans the insulated box. It uses evaporation of a refrigerant to provide cooling, resulting in comfort level rooms.

The compressor compresses the refrigerant, causing it to become a hot, high pressure gas (red in the diagram).

The hot gas runs through a set of coils (condenser), dissipating heat and condensing into a hot liquid refrigerant.

The hot liquid refrigerant runs through an expansion valve and evaporates, becoming a cold, low pressure liquid gas refrigerant mixture (light blue in the diagram).

The cold refrigerant runs through a set of coils (evaporator), absorbing heat from a blast of air re-circulated within the air conditioned space, thus cooling the air inside the building.

Think twice before switching on an AC. Use a fan, unless it’s absolutely necessary.

Set the thermostat at 26oC. An extra 1oC difference in the temperature adds 4% to the cooling energy costs.

You can set the thermostat at even higher temperatures, if fans are used in air conditioned rooms.

Install a programmable thermostat to track your schedule.

Keep filters clean. Clean ductwork / vents. Clogged filters reduce air flow, forcing compressors to work hard.

Keep windows / doors closed, when the cooling system is on. Window shades can reduce / block sunlight and heat during daytime.

Install window unit ACs on the shadiest side of the building. Grow trees to shade the unit from sunlight.

Seal cracked / broken windows, electrical outlets and switches on walls. Seal leaks where plumbing, ducting and electrical wiring penetrates walls.

Curtains inside the glazed windows offer little or no help to reduce the solar heat gain. Always attempt to block solar rays outside the glazed area.


Limit the use of ceiling fans. They consume more energy than pedestal fans or table fans.

Beware of old ceiling fans. Even if they work reliably and faithfully, they may not be the most efficient ones in service.

Keep your fan in good working condition. Check the manufacturer’s recommendation for care and maintenance.

Place the fan so that you feel the breeze directly.

Did you know?

Landscaping is a natural and beautiful way to help keep your home cool and comfortable. Carefully position trees to deliver effective shade. Such trees can save upto 25% of a typical household’s comfort-related energy.

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