Cooling power is not the only concern when choosing an air conditioner unit. You must also consider its Energy Efficiency Ratio or EER. A higher EER means that an appliance is capable of transforming electricity to utility without wasting much power. Nowadays, the standard minimum EER is 10. Hence, if you have old units with a rating of 8, it is time to replace them. Just make sure that your new unit has an Energy Star label to guarantee genuine EER rating.
Another important consideration is the BTU (British Thermal Unit) Rating of the unit. In layman’s terms, this is the ability of the conditioner to cool a place at a given span of time. Air conditioner units use mechanical parts like the compressor and fan. It uses internal pressure to move the cooling fluids in its tubes suck the warm air in and force cool air out. These mechanical processes require electricity. If the unit has a high BTU rating, the components require more electricity. Hence, it is important to just choose the right amount of BTU for your house.Higher BTU results in faster cooling, but the rate of air suction cannot remove water vapor from the room. Besides power wastage, this will result in an uncomfortable and clammy atmosphere inside the house. There is a prescribed BTU, depending on the room size. There are free charts in the web that will help you size your air conditioner BTU.