Ton of refrigeration

\mathrm{TR} = 3516.8528420667\ \text{W}

Value	3516.8528420667 W
Status	Exact by definition — no uncertainty
Source	ASHRAE; NIST SP 811 (exact by definition)
Categories	Thermodynamic Engineering & Trade

TR in every power unit

milliwatt	3,516,852.8 mW
watt	3,516.8528 W
kilowatt	3.5168528 kW
megawatt	0.0035168528 MW
horsepower (mechanical)	4.7161773 hp
BTU per hour	12,000 BTU/h
ton of refrigeration	1 ton

Learning zone

The ton of refrigeration is a survivor from the ice trade. Before mechanical refrigeration, cooling was bought as blocks of ice, so the natural way to rate a new machine was by how much ice it replaced: melting a short ton — 2000 lb — of ice over 24 hours requires 2000 × 143.4 BTU spread over a day, which rounds to the defined 12 000 BTU/h, or 3516.85 W.

It is exact by definition, since the international-table BTU is exact. The unit refuses to die because chiller efficiency is quoted against it: kW per ton, where 0.5 kW/ton is excellent and 1.0 kW/ton is mediocre, and the coefficient of performance is 3.517 divided by kW/ton. A note for anyone reading European datasheets: a ton is a US short ton here, and a "ton" of air conditioning has nothing to do with the weight of the equipment.

Used by these solvers

Tons of Refrigeration from BTU/hr

T = \frac{\dot{Q}}{12{,}000\ \text{BTU/hr}}

Chiller Efficiency (kW per Ton)

\mathrm{kW/ton} = \frac{\dot{W}\ [\text{kW}]}{\dot{Q}\ [\text{tons}]}

Coefficient of Performance (COP)

\mathrm{COP} = \frac{\dot{Q}}{\dot{W}}

Energy Efficiency Ratio (EER)

\mathrm{EER} = \frac{\dot{Q}\ [\text{BTU/hr}]}{\dot{W}\ [\text{W}]}