Ton of Refrigeration (TR) is a unit used to express the refrigerating capacity of a refrigeration or air-conditioning system.

❄️ Definition of 1 TR

1 Ton of Refrigeration is the rate of heat removal required to freeze 1 US ton (2000 lb) of water at 0°C into ice at 0°C in 24 hours.

⭐ Most Important Value

1 TR = 3.517kW

This is one of the most important values to remember for SSC JE, RRB JE and other Mechanical Engineering exams.

🔹 Important Conversions

• 1 TR = 3.517 kW
• 1 TR = 211 kJ/min
• 1 TR ≈ 3024 kcal/hr
• 1 TR ≈ 12,000 BTU/hr

🔹 Why is it called “Ton”?

The term “ton” comes from the traditional ice-making industry.

Historically, refrigeration capacity was related to the amount of ice produced. One ton of refrigeration represents the rate of heat removal required to freeze approximately one US ton of water into ice at 0°C in 24 hours.

📌 Example

If an air conditioner has a cooling capacity of 2 TR:

2 X 3.517 = 7.034 kW

Therefore:

2 TR ≈ 7.03 kW of refrigeration capacity.

⚠️ Note: Refrigeration capacity and electrical power consumption are not the same thing.

🎯 Exam Point

If asked:

“1 Ton of Refrigeration is equal to?”

Remember:

1TR = 3.5kW

🔥 Quick Revision

1 TR = 3.517 kW = 211 kJ/min ≈ 3024 kcal/hr ≈ 12,000 BTU/hr

Useful for: SSC JE | RRB JE | GATE | Diploma | Mechanical Engineering