What is TR in air conditioning, and how many tons does your space need?

TR stands for Tons of Refrigeration. One TR is the cooling effect of melting one ton of ice in 24 hours, about 12,000 BTU per hour. To size cooling you estimate the building heat load and convert it to TR. A rough guide for Delhi NCR is roughly one TR for every 90 to 120 square feet, adjusted for sun, occupancy and equipment.

Why TR matters

Buy too little tonnage and the space never cools. Buy too much and you waste money on equipment and power, and the system short cycles. Correct sizing is the difference between a comfortable, efficient building and an expensive, unreliable one.

How TR is estimated

Engineers add up the heat entering a space: through walls and roof, through glass, from people, from lights and equipment, and from fresh air. That total heat load in BTU per hour, divided by 12,000, gives the TR. Rules of thumb give a quick estimate, but a proper heat load calculation is what confirms the number.

Quick guide by space type in Delhi NCR

• Home living areas: about 120 sq ft per TR
• Offices: about 95 sq ft per TR
• Retail and showrooms: about 90 sq ft per TR
• Restaurants with kitchens: about 65 sq ft per TR
• Server rooms: about 50 sq ft per TR

Once you have a tonnage, the next question is which system delivers it. For most commercial buildings that comes down to VRF or VRV against a central plant, which we cover in our commercial HVAC work.

FAQ

How many tons of AC do I need for a 1,500 sq ft home?

Around 12 to 14 TR total across the home, depending on sun exposure and occupancy.

Is a higher TR always better?

No. Oversized systems cost more and run inefficiently. Right sizing is the goal.

Can I get an exact figure online?

You can get a solid estimate. Only a site survey and heat load calculation give the exact TR.

Not sure of your tonnage? Try the cooling calculator on our homepage, or request a site survey and an engineer will run the heat load properly.