Trane TRG-TRC016-EN manual Standard Rating Conditions

period one

Types of Water Chillers

notes

Standard Rating Conditions

	evaporator	condenser	rating
chiller type	flow rate	flow rate	standard
vapor-compression
• reciprocating	2.4 gpm/ton	3.0 gpm/ton	ARI
• scroll			550/590–1998
• helical-rotary	[0.043 L/s/kW]	[0.054 L/s/kW]
• centrifugal
absorption	2.4 gpm/ton	3.6 gpm/ton
• single-effect
	[0.043 L/s/kW]	[0.065 L/s/kW]
• double-effect,		4.0 gpm/ton	ARI
indirect-fired	2.4 gpm/ton	[0.072 L/s/kW]	560–1992
• double-effect,	[0.043 L/s/kW]
		4.5 gpm/ton
direct-fired		[0.081 L/s/kW]

water leaving evaporator = 44°F [6.7°C]	Figure 23
water entering condenser = 85°F [29.4°C]

The standard rating conditions used for ARI certification represent a particular set of design temperatures and flow rates for which water-cooled and air-cooled systems may be designed. They are not suggestions for good design practice for a given system—they simply define a common rating point to aid comparisons.

In fact, concerns toward improved humidity control and energy efficiency have changed some of the design trends for specific applications. More commonly, chilled-water systems are being designed with lower chilled-water temperatures and lower flow rates. The water flow rate required through the system is decreased by allowing a larger temperature difference through the chiller.

20 TRG-TRC016-EN