Air Conditioning Tonnage

What does Air Conditioning Tonnage mean?

“Air Conditioning Tonnage” is one of the most mysterious phrases in the HVAC industry. Sometimes it seems like air conditioning technicians and engineers have an entire language of their own. Some of the words these folks use are common, but the way they use them is not. If you are an air conditioning repair customer, being educated in this terminology could be helpful.

Air Conditioning Tonnage is a term for rating air conditioning units. Many people think it has something to do with how many tons of air the unit handled in a given time.

Air Conditioning Tonnage – What is it?

Air conditioning tonnage has nothing to do with weight. A ton, as used in the HVAC field, is a term that describes how much heat the AC unit can remove from a home in one hour. The measurement for heat is the British thermal unit (BTU). One ton of air conditioning can remove 12,000 BTUs of air per hour. A four ton unit can move 48, 000 BTUs and so on. Therefore, the more tonnage an AC unit is rated at, the more air it can cool.

Most homes, depending on ceiling heights, windows, and airflow will need a ton of air conditioning for every 400 to 1,000 square feet. Higher air conditioning tonnage can mean higher energy costs because the more tonnage an air conditioner is rated for the more work it is doing. When buying a new air conditioning installation, get one that is EnergyStar certified. They are the most efficient units available. And AC Warehouse has them.

Fun facts: Unbelievable as it seems, the entire formula has to do with 19th century ice production during the winter on the Hudson River and how much heat one needs to melt one ton of ice in a 24-hour period. That translates in modern day science to one ton of air conditioning equals 12,000 BTUs. Some people claim that Willis Carrier, the inventor of air conditioning, introduced the usage of the term “tonnage”. If your scientific curiosity has you burning to know more, here is a link: https://en.wikipedia.org/wiki/Ton_of_refrigeration

Use our AC Tonnage Calculator to estimate what size of air conditioning unit is best for you.