WHY IS 12000 BTU A TON?

Every apprentice in the HVAC industry or anyone considering buying an air conditioning system would ask this question. Why is BTU per ton rated at 12000? Before we can answer this, we need to understand what a BTU is and what a ton is in relation to AC systems. Simply put, a British Thermal Unit (BTU) is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

THE CONCEPT OF A “TON” IN REFRIGERATION

In air conditioning and refrigeration, a ton is a unit of cooling capacity. It is defined as the amount of heat that can be removed from a space in one hour. If we say an air conditioner has 2 tons of cooling capacity, it means it can remove 24,000 BTUs of heat from a space in one hour.

Why is a ton rated at 12000 BTUs?

The reason why a ton is rated at 12,000 BTUs is rooted in history. In the early days of refrigeration, ice was used to cool food and drinks. A ton of ice was found to be able to melt and absorb 12,000 BTUs of heat while doing so. This relationship between a ton of ice and 12,000 BTUs became the standard for measuring cooling capacity, and it has been used ever since.

Calculating BTU Requirements

To determine the BTU requirements for a space, several factors need to be considered, including:

How to Choose the Right Size Air Conditioner

When choosing an air conditioner, it is essential to select a unit with the right capacity for the space that needs to be cooled. An air conditioner that is too small will not be able to adequately cool the space, while an air conditioner that is too large will be inefficient and waste energy.

CONCLUSION

The relationship between a ton and 12,000 BTUs is a historical convention that has been used for many years. It is essential to understand this relationship when sizing an air conditioner for a space, as an improperly sized unit can lead to discomfort and wasted energy.