Why Is Your Cooling Capacity Measured in Tons?
The cooling capacity of the typical residential air conditioner is two to four tons. Though, it doesn’t mean that the air conditioner weighs 4,000 to 8,000 pounds. “Ton” in HVAC terminology and context is a measurement of heat energy movement rather than a measurement of weight.
“Tons” of Cooling Back in the 1800s before modern air conditioning, people cooled their homes and businesses with blocks of ice. The ice was harvested from frozen rivers and lakes during the winter and spring. The ice was measured by the ton. Millions of tons of ice, in fact, were harvested each year. It just so happens that it takes 12,000 BTUs of heat transfer an hour to melt one ton of ice in a 24-hour period.
So, a 2-ton air conditioner refers to an air conditioning system that can extract 24,000 BTUs of heat energy an hour from a building, which is the heat energy it takes to melt two tons of ice in 24 hours. Consequently, the word “ton” found a place in HVAC jargon even though it had a different meaning in modern air conditioning.
Sizing an Air Conditioner
Correctly sizing air conditioner cooling capacity is vital when installing a system. If you install the wrong size system, you may waste money and the air conditioner can’t reach peak efficiency. Air conditioner sizing and selection should be determined using Manual J and Manual S from the Air Conditioning Contractors of America (ACCA). The manuals were developed in the 1970s to improve building efficiency and comfort. The following are a few of the specifications an HVAC pro will use to determine appropriate air conditioner sizing:
- Window number and size
- Air infiltration rate and R-values
- Local weather patterns
- Your home’s cubic feet and much more
For more details about air conditioner cooling capacity, contact Sobieski Services, Inc. today.
Our goal is to help our customers in Delaware, Pennsylvania, Maryland and New Jersey learn more about energy and home comfort issues – especially HVAC and plumbing issues – so that they can save money and live in healthier, more comfortable homes.
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