HVAC ton rating

[dale1627]

How can I calculate the ton rating of an an HVAC unit?

Dale

 

[walkes]

If its an existing unit. Check the nameplate for the serial number and give the manufacturer's representative a call.

 

[Rleonjr79]

In my understanding a "tonnage" of an A/C unit can be determined by the BTU rating of said unit. i.e. 12,000BTUH = 1Ton. Hope this helps.

 

[quark]

If it is an existing unit then you can calculate the actual tonnage by taking DBT, WBT at inlet and outlet of the cooling coil and flowrate in cfm.

You get the load Q (btu/hr) = 4.5 x cfm x (h1-h2) where h1 is inlet enthalpy in btu/lb(corresponding to inlet DBT and WBT, from a psychrochart) and h2 is outlet enthalpy. Tonnage calculation is already covered in previous post.

 

[y1a1n1k1s1]

dale1627 - from one electrician to another - a simple quick way would be to look at the model number - say it's a Carrier 38CKB060600 - look at the numbers after the letters (060), these are your BTU's. Devide them bt 12 and this will give you your tons 60/12 = 5 tons. Good luck.