The cost of saving

There's nothing like statistics to drive home the impact our lifestyles have on the environment and our utility bills. This is clearly evident when you consider something as basic as air-conditioning. According to the Dubai Electricity and Water Authority (DEWA), air-conditioning accounts for a major chunk of electricity consumption in Dubai.

A press report from the consumer electronics company LG cites recent statistics from DEWA showing that the demand for energy increased by 24 per cent in 2007, though power station capacity grew only by 20 per cent.

Commercial and residential developments were responsible for most of the power consumption at 42 per cent and 31 per cent respectively.

Air-conditioners accounted for the bulk of the power consumption at 60 per cent, followed by electronic equipment at 17 per cent and home appliances at 15 per cent. That's just power consumption.

The effect air-conditioning has on the environment is also daunting. According to the US Department of Energy (Energy Efficiency and Renewable Energy), in an average air-conditioned home, air-conditioning consumes more than 2,000 kilowatt-hours of electricity per year, causing power plants to emit about 3,500 pounds of carbon dioxide and 31 pounds of sulphur dioxide.

When you multiply these figures by thousands of such homes in a city, you realise the full impact on the environment.

Governments, manufacturers and consumers can help change the situation. The Dubai government, for instance, has issued property developers a directive to follow 'green building' standards in their constructions to address issues such as energy-efficient cooling among others.

K. W. Kim, President, LG Electronics, Middle East and Africa, says green buildings can significantly minimise the energy load on the power stations, which face the challenge of satisfying the growing demand for power in the region.

Eco-friendly refrigerants

Another measure, says Chris Ahn, General Manager, Air-conditioning, LG Electronics Gulf FZE, to reduce the load attributed to air-conditioners would be the introduction of more stringent specifications related to products that use eco-friendly refrigerants similar to those in Europe and the US.

He says that if more companies in the region use inverter technology and eco-friendly refrigerants, it could bring down energy costs and not harm the environment.

As part of the company's initiative to adopt a more eco-friendly approach to doing business, LG uses ozone-friendly refrigerants in its air-conditioners and materials and processes based on LEED and ROHS standards (which are linked to the restriction of the use of certain hazardous substances in electrical and electronic equipment) to manufacture their equipment.

"Keeping in line with our initiative, we have also adopted measures such as recycling materials used to manufacture our units and treating the waste water at our plants," says Ahn. DEWA has been trying to raise awareness about using less electricity and water across all consumer categories in Dubai.

"These efforts aim at reducing the wastage of available resources, utilising these resources rationally and protecting the environment through reducing the processes required in producing electricity and water, and thereby reducing the emission of harmful gases into the atmosphere," says Engineer Amal Koshak, Manager Investor Services, DEWA.
Conserving energy DEWA recommends several ways to conserve electricity used for air-conditioning purposes.

"If you are in the initial phase of planning your house or building, you should implement the thermal insulation guidelines in your building.

This will help maintain the indoor temperature for a long period of time and also increase the efficiency of the cooling system. Make sure that doors and windows are sealed in a manner that will help reduce the time air-conditioning units are switched on to cool the place," says Koshak.
Koshak also recommends using more than one air-conditioning unit (for example, one for the living room, guest room, bedroom and the kitchen).

Although this may marginally increase the capital cost, it will help in conserving electricity, especially if the units in unoccupied spaces are switched off. Using energy-efficient equipment for air-conditioning is also important.

She recommends looking at more than one vendor before purchasing an air-conditioner and using variable speed drives (VDS) with air-conditioning equipment. While several manufacturers make energy-efficient air-conditioners, it's important that consumers become aware of the factors that will help them choose one that can meet their cooling needs without increasing their utility bills.

Abby Thomas, Product Manager, Panasonic Marketing Middle East, says the simplest way to ascertain energy efficiency is to divide the cooling output (measured in British thermal units per hour) of the air-conditioner by the power consumption or energy input (in watts).

"The number you get gives you the Energy Efficiency Ratio (EER) of the unit. The higher the energy efficiency ratio is, the less power it will consume, which will inevitably result in lower utility bills. Using this formula you can pick out an appropriate air-conditioner," says Thomas.

In addition to this factor, consumers can also look at advanced features offered by the unit. Panasonic, for instance, has incorporated both purifying and cooling features within a single unit. Its new e-ion air purification system features a highly durable compressor and fan motor to maintain comfortable room temperatures even under the hottest conditions while simultaneously tackling impurities such as dust and other pollutants.

Reducing power consumption

Thomas says these units cut power consumption because at any given time you can turn on either the air-purifier or air-conditioner or both. Switching on the air-purifier automatically ensures that the fan inside the indoor unit is strong enough to circulate air in the room, which results in not having to turn on the compressor.

This helps to increase the lifespan of the unit since power consumption is reduced as the compressor is not repeatedly switched on and off.
LG also recently launched a line of air-conditioners called Multi V, which it claims reduces power consumption by up to 70 per cent.

Ahn says the Multi V system employs a heat recovery process that can operate both cooling and heating simultaneously, using only one outdoor unit and effectively serving both cost and energy efficiency needs.

Unlike conventional, first and second generation air-conditioners, this third generation air-conditioner is especially suitable for hotels, hospitals and buildings where space-specific heating/cooling control is essential.

Ahn says that in addition to cutting utility costs, energy-efficient air conditioners also increase the average lifespan of air-conditioners, which is around 15 years.

Optimal performance

The type and placement of units can also help attain optimal performance.

For example, placing of outdoor units closer to the actual room (such as on a balcony) helps reduce the amount of copper wiring used and is also beneficial when a technical failure raises the need to zero in on the hitch.
Even the type of unit considered is important.

Many villas in the region are equipped with ducted units. This can prove to be a serious health hazard as people in all rooms are breathing the same air. Such units are also costly to maintain and difficult to clean.

An easy solution to this is to use split units fitted with high-efficiency filters to reduce cooling loads, These are especially optimal for high occupancy areas such as malls and cinemas.
Thomas also stresses the importance of thermal insulation and the usage of good insulation materials.

According to DEWA, a good thermal insulation system can reduce the consumption of electrical energy by up to 40 per cent during the cooling process inside the building.

DEWA recommends materials that are resistant to heat, fire, humidity and erosion, in addition to materials that are long-lasting, non-expansive and non- shrinkable in the prevailing weather conditions of Dubai.
He mentions that it is wise to double insulate all power cables.

In older buildings, for example, having two or more air-conditioners installed would increase the load on the cables and hence frequent checks must be made on breakers and fuses.

Although the trend is to lower indoor temperatures as the external temperatures soar, international research proves that the optimal ambient temperature for humans is between 21 and 23 degrees Celsius.

Hence, it is best if you keep the thermostat of your unit at that level. Reducing the temperature lower to 16 or 17 degrees Celsius causes problems such as water leakage in the unit, and it also dries the human skin.

With energy-efficient equipment, these suggestions can go a long way in meeting your cooling needs, lowering your utility bills and increasing your contribution towards the protection of the environment.

According to the Dubai Electricity and Water Authority,
air-conditioning accounts for a major chunk of electricity
consumption in Dubai. The Dubai government has issued
property developers a directive to follow 'green building'
standards in their constructions to address issues such
as energy-efficient cooling among others

Tips to increase efficiency

Here are some ways to help increase the efficiency of your
air-conditioner and lower your electricity bills.

• Set the air-conditioner's temperature at 24 degrees Celsius in occupied spaces.
• Set the air-conditioner's temperature at 28 degrees Celsius in vacant rooms and spaces or switch the unit off.
• Use rotating doors to prevent conditioned air leakage.
• Make sure you switch off all air-conditioning in the house when you go out for short or long periods, for example holidays.
• Ensure you service and maintain the air-conditioning units at regular intervals. Measures such as cleaning the air filters will increase the efficiency of the unit and reduce running time, thus saving electricity.
Courtesy: DEWA