Frequently Asked Questions
As a homeowner, one of the toughest decisions you’ll have to make about your air conditioner is when it’s time for a new home AC system.
You’re researching online or have heard talk about variable speed AC compressors, two-stage compressors, and the single-stage compressor and Seer ratings. let us help by explaining some of those AC systems and related terms.
WHAT DOES THE SEER RATING OF AN AC SYSTEM MEAN?
An air conditioning systems energy efficiency is classified by the S.E.E.R. rating. The SEER, which stands for (seasonal energy efficiency ratio), rating of the energy efficiency an air conditioning unit during a full season of operation. Using an air conditioning system with a higher SEER rating means the AC system uses energy more efficiently than an air conditioning unit with a lower SEER rating. Higher Seer rating saves you money on your home cooling utility bills. The SEER rating seems to be based on the average of 83 degrees Fahrenheit. So for every 5 degrees warmer than 83 degrees, deduct 1 from the SEER value. An example would be if you have a 10-year-old AC system that has a SEER value of 10 and its 98 degrees outside you would have a 7 SEER system. Where the highest SEER system we sell and install has a 26 SEER rating, at 98 degrees, it would still be a highly efficient 23 SEER.
AC CAPACITY (TON)
We know that the air conditioner’s capacity number of tons doesn’t refer to its actual weight. This number actually refers to the amount of heat In British Thermal Units (BTU) the air conditioner system can remove from a house within one hour. One ton of AC capacity is 12000 BTU’s per hour. So why ton you ask, I know your wondering so here we go, believe it or not, is based on a 1-ton block of ice which is 2000 pounds.
I will explain, before the invention of refrigerators and air conditioning, people who could afford it, used ice to cool their homes and food. The math is based on the melting (heat transfer) of a 2000 pound block of ice over a 24 hour period at 32 degrees f. If that block of ice melts evenly over the course of the day, it absorbs heat at the rate of 11,917 BTU/hour. Rounded up, we get 12,000 BTU/hour or one ton of AC capacity.
SINGLE-STAGE AC COMPRESSOR
A single-stage AC compressor operates at one speed all the time full cold, the thermostat controls the temperature in the house by turning the AC system and compressor on and off. From an efficiency standpoint, these are the least efficient type of units, as they are always running at full cold. A compressor draws the most power when it turns on. That is why you will see your lights flicker when your air conditioner turns on. I am sure you have heard your neighbors AC turning on and off all day and night long. This equals a large power bill every month.
TWO-STAGE / MULTI-STAGE AC COMPRESSOR
The two-stage AC compressor means the compressor has two levels of operation: high for the very hot summer days and low for milder Summer days. A two-stage AC unit is like actually having two units for the price of one. On milder days the compressor comes on initially at 70% and if it can’t cool your house at that level it then moves to 100%. Since the low setting is adequate to meet home cooling demands 80% of the time, a two-stage unit runs for longer periods and produces a more even leveled home indoor air temperature. The two-stage compressor is more efficient than the single-stage compressor because it doesn’t cycle on and off as much, which means less wear and tear on the compressor. The two-stage system also removes twice as much humidity as the single-stage system because the two-stage stays on at the lower level for a longer period of time.
VARIABLE-SPEED AC COMPRESSOR
The Variable speed compressor is the quietest most efficient offering we have today. It operates at different speeds depending on the need for cooling, anywhere from 35-100%. These compressors offer more speeds than the two-stage systems. This allows the AC to cool your home at lower speeds for longer periods of time while still having the higher speeds available for when the outdoor temps get higher. The variable speed AC systems run longer without cycling on or off and stays only at the speed needed to keep you comfortable. This makes the variable speed system the most energy-efficient of the three types.