## Calculating chiller and cooling tower refrigeration in tons

Cooling towers tons pairs the water-cooled chiller tons and the water-cooled condenser tons.

### Chiller Refrigeration Tons

A water-chiller refrigeration ton is defined as:

*1 refrigeration ton = 1*

*TONS*12,000 Btu/h = 3,025.9 k Calories/h = 12,661 kJ/h_{cond}=A ton is the amount of heat removed by an air conditioning system that would melt

*1 ton**(2000 lbs.)*of ice in*24 hours:**288,000 BTU/24 hr = 12,000 BTU/hr*

#### Converting Btu to Tons of Refrigeration

Btu per hour | Tons of Refrigeration |

6000 | 1/2 |

12000 | 1 |

18000 | 1 1/2 |

24000 | 2 |

30000 | 2 1/2 |

36000 | 3 |

42000 | 3 1/2 |

48000 | 4 |

54000 | 4 1/2 |

60000 | 5 |

### Cooling Tower Tons

A cooling tower ton is defined as:

*1 cooling tower ton = 1 TONS*

_{evap}=*1 TONS*15,000 Btu/h = 3,782 k Calories/h = 15,826 kJ/h_{cond}x 1.25 =The equivalent ton on the cooling tower side actually rejects about

*15,000 Btu/h*due to the heat-equivalent of the energy needed to drive the chiller's compressor. This equivalent ton is defined as the heat rejection in cooling 3 U.S. gallons/minute (1,500 pound/hour) of water 10°F, which amounts to 15,000 Btu/hour, or a chiller coefficient-of-performance (COP) of 4.0 - a COP equivalent to an energy efficiency ratio (EER) of 13.65.### Heat Load and Water Flow

A water systems heat load in

*Btu/h*can be simplified to:h = c_{p}ρ q dt

=(1 Btu/lb_{m}^{o}F) (8.33 lb_{m}/gal) q(60 min/h) dt

= 500 q dt(1)

where

h= heat load (Btu/h)

c_{p}= 1 (Btu/lb_{m}^{o}F) for water

ρ = 8.33 (lb_{m}/gal) for water

q= water volume flow rate (gal/min)

dt= temperature difference (^{o}F)

### Example - Water Chiller Cooling

Water flows with

*1 gal/min*and*10*temperature difference. The ton of cooling load can be calculated as:^{o}FCooling load = 500 (1 gal/min) (10^{ o}F) / 12,000

= 0.42 ton