How to choose an energy efficient air conditioner

Due to rapid demand and the effort to minimize the global warming, the technology of energy efficient air conditioners are continuously being developed. Minimizing the power consumption of air conditioners will significantly contribute to decrease in carbon footprint as most of our power utilities still use fossil fuel to generate the electricity. In general, the more efficient the equipment is, the more costly it is compared to the regular ones. Here are some steps that you can take when choosing energy efficient air conditioners to purchase.

Air Conditioner's capacity to cool

Air Conditioner's capacity to cool a room is defined as the capacity to remove  heat load from a room for achieving a certain room temperature and humidity. Basically, it is designed as 24°C temperature and 55% Relative Humidity. Human body feels comfortable with this combined temperature and Relative Humidity. Heat load is measured as BTU/hr. BTU acronym stands for British Thermal Unit. 1 BTU/hr is the heat energy needed to increase 1 pound of water by 1°F.

Basically, a 1 HP (horse power) air conditioning equipment can remove 9,000 BTU/hr of heat. With improved technology, some machines can remove 10,000 BTU/hr of heat with the same capacity. The higher the listed BTU/hr, the greater the cooling capacity. So, correct sizing of the air conditioner for the room is very important. Oversized air conditioner is not cost effective and also causes some problems. Oversized air conditioner turns on and off right away and can't remove humidity. You will have higher energy bill for oversized air conditioner.

 

Comparison between Non-Inverter and Inverter Air Conditioner

An inverter air conditioner is comparatively more efficient than a non-inverter air conditioner. In the case of inverter air conditioner, rotation of the compressor is varied according to load requirement. It contribute to save significant amount of energy. On the other hand, the non-inverter compressor is not able to vary its speed according to load requirement. It just can turn ON and OFF which consumes more energy. A DC inverter compressor is more efficient than AC inverter.
 

Checking efficiency

Different model will have different values and it also varies with different manufacturers. So, it is very important to check the brochures for the efficiency of the model. COP is the ratio of the cooling capacity(W) vs the power input(W). The higher the value, the more efficient it is as it is able to provide more cooling for the same power input. If it is not mentioned then calculate yourself. For ease of cooling capacity conversion, 1W=3.4121 Btu/h. You should choose a higher COP model. EER is the ratio of the cooling capacity(Btu/h) vs the power input(W). As with COP, choose a higher EER rating and the unit will consume less energy for the same capacity. SEER is the ratio of the total cooling that the equipment is able to provide over the entire season (Btu) Vs the total energy (Watt-hours) consumed. SEER is more accurate as it takes into consideration the start-up and shut-down cycles of the air conditioner. You should choose a higher value for energy efficient air conditioners.

Rating of Energy Star

According to laboratory testing, there are different energy ratings for different models of air conditioner in every country. You should choose the air conditioner which has the highest rating as this would mean that the unit is comparatively more efficient than lower star rating.

Sensor with advanced technology

Some manufacturers have built sensor with advanced technology. For example, we can say about built-in infra-red sensor. It can detect the presence or absence of the occupants in the room. If it does not detect any movement for a certain period of time, it will  automatically adjust the set temperature higher to minimize the temperature in the room. This will significantly contribute to save your electricity bill.