Refrigeration & Equipment Engineering

Unit 9 - Heat load calculation

9.2.Unit of Refrigeration
The practical unit of refrigeration is expressed in terms of tonne of refrigeration.
A tonne of refrigeration effect produced by the uniform melting of one tonne (1000 kg) of ice from and at 0^oC in 24 hours. Since the latent heat of ice is 335 KJ/kg.

Therefore
1TR = 1000 x 335 JH ub 24 hours

1000x335
= ---------------- = 232.6 KJ/min
24x60

In actual practice, one tonne of refrigeration is taken as equivalent to 210KJ/min or 3.5KW (i.e. 3.5 KJ/S).