Things To Know Before Purchasing a New Air Conditioner
Whether you are selecting an air conditioner system for a new home or replacing an existing unit, there are three factors that should be considered – size of the system, energy efficiency, and cost relative to the size and achievable energy savings.
Every refrigeration air conditioning system is rated by the number of BTU’s it can remove per hour or “tons” of cooling it provides. This rating refers to the amount of heat it can remove in one hour’s time – one ton equals 12,000 BTU/hour. For example, a three ton air conditioner would remove 36,000 BTU’s per hour.
If the air conditioner is under-sized, it will not be able to cool the indoor space to the desired temperature on very hot days.
If the AC unit is over-sized, it will cycle on and off frequently most of the time and except for the very hottest time periods, will not operate near its intended efficiency.
Two groups, the Air Conditioning Contractors of America (ACCA) and the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) publish calculation procedures for sizing central air conditioning systems.
Air conditioning systems have an operating efficiency, and that efficiency is an indicator of how well the unit converts input energy into output cooling.
As of January 23, 2006, the Department of Energy has required central air conditioning manufacturers to meet a minimum Seasonal Energy Efficiency Ratio (SEER) of 13. The previous standard was 10.
The SEER value measures the efficiency of a cooling system (air conditioner or heat pump) over the full cooling season. It takes into account the variation in temperatures that can occur within a season, and is the average number of BTU’s of cooling delivered, for every watt-hour of electricity used by the unit.
The Department of Energy determined that a SEER rating of 13 was the highest value both technically feasible and economically justified.