Absorption Water Chilling and Water Heating Package: A factory designed and prefabricated assembly employing water as the refrigerant and consisting of an evaporator, absorber, condenser, generator(s) and solution heat exchangers, with interconnections and accessories used for chilling or heating water. The package utilizes single or multiple reconcentrations of an absorbent solution. The reconcentrations of the absorbent are known as effects. A single effect package employs one step reconcentration of the absorbent in the generator. Water vapor is released after the heat energy is introduced into the generator. The concentrated absorbent is returned to the absorber where it can absorb water vapor flashed off in the evaporator. A double effect package employs a two step reconcentration of the absorbent through the use of an additional high temperature generator.
Application Rating: A rating based on tests performed at application Rating Conditions (other than Standard Rating Conditions).
Bubble Point: Refrigerant liquid saturation temperature at a specified pressure for refrigerant mixtures.
Coefficient of Performance (COP): A ratio of the cooling capacity in watts [W] to the Total Power Input, in watts [W] at any given set of Rating Conditions, expressed in watts/watt [W/W]. For heating COP, supplementary resistance heat shall be excluded.
Compressor Saturated Discharge Temperature: For single component and azeotrope refrigerants, it is the saturated temperature corresponding to the refrigerant pressure at the compressor discharge. For zeotropic refrigerants, it is the arithmetic average of the Dew Point and Bubble Point temperatures corresponding to refrigerant pressure at the compressor discharge. It is usually taken at or immediately downstream of the compressor discharge service valve (in either case on the downstream side of the valve seat), where discharge valves are used.
Condenser: A refrigeration system component which condenses refrigerant vapor. Desuperheating and subcooling of the refrigerant may occur as well.
- Air-Cooled Condenser: A component which condenses refrigerant vapor by rejecting heat to air mechanically circulated over its heat transfer surface causing a rise in the air temperature.
- Air-Cooled Heat Reclaim Condenser: A component which condenses refrigerant vapor in the process of rejecting the heat of condensation to air causing a rise in the air temperature. This Condenser may be a separate Condenser, the same as, or a portion of the Air-Cooled Condenser.
- Evaporatively-Cooled Condenser: A component which condenses refrigerant vapor by rejecting heat to a water and air mixture mechanically circulated over its heat transfer surface, causing evaporation of the water and an increase in the enthalpy of the air.
- Water-Cooled Condenser: A component which utilizes refrigerant-to-water heat transfer means, causing the refrigerant to condense and the water to be heated.
- Water-Cooled Heat Reclaim Condenser: A component which utilizes refrigerant-to-water heat transfer means, causing the refrigerant to condense and the water to be heated. This Condenser may be a separate condenser, the same as, or a portion of the Water-Cooled Condenser.
Cooling Only Mode: Operational mode of a Direct-Fired chiller/heater which supplies (only) chilled water.
Dew Point: Refrigerant vapor saturation temperature at a specified pressure.
Direct Fired Package: This type of package reconcentrates the absorbent from heat energy through the combustion of natural gas, LP gas, or oil.
Energy Input: The heat content of the fuel, steam, or hot water, excluding the electrical input.
- Total Power Input: Power input of all components of the unit.
- Direct Fired: Energy Input is the gross heating content of the fuel based on the Higher Heating Value in MBH [kW].
- Indirect Fired: Energy Input is the heat content of the steam or hot water in MBH [kW].
Energy Efficiency Ratio (EER): A ratio of the cooling capacity in Btu/h [W] to the Total Power Input in watts [W] at any given set of Rating Conditions, expressed in Btu/(W·h).
Field Fouling Allowance: Provision for anticipated fouling during use, h•ft2 •F/Btu [m2•°C/W].
Fouling Factor: The thermal resistance due to fouling accumulated on the heat transfer surface.
Heat Reclaim Coefficient of Performance (COPHR): A ratio of the Net Heat Reclaim Capacity (Btu/h) to the Total Power Input to the unit, W converted to Btu/h.
Heat Reclaim Water-Chilling Package: A factory-made package, designed for the purpose of chilling water and containing a Condenser for reclaiming heat. Where such equipment is provided in more than one assembly, the separate assemblies are to be designed to be used together, and the requirements of rating outlined in this standard are based upon the use of matched assemblies. It is a package specifically designed to make use of the refrigerant cycle to remove heat from the refrigerant and to reject the heat to another fluid (air or water) for heating use. Any excess heat may be rejected to another medium, usually air or water.
Heating Only Mode: Operational mode of a Direct-Fired chiller/heater which supplies only hot water.
High Pressure Steam: Steam pressures above 15.0 psig [103 kPa], but below 150 psig [1030 kPa].
Higher Heating Value (HHV): The amount of heat produced per unit of fuel when complete combustion takes place at constant pressure, the products of combustion are cooled to the initial temperature of the fuel and air, and the vapor formed during combustion is condensed, Btu/lb or Btu/ft3 [W/m3] for gaseous fuel, or Btu/lb [J/kg] or Btu/gal for liquid fuel.
Hot Water Heating Option: Hot water can be provided from an absorption chiller/heater through either of two circuits:
- Through the evaporator circuit (2-pipe system); typically applied at temperatures up to 140°F [60.0°C] (standard temperature hot water).
- Through a separate hot water heat exchanger (4-pipe system); typically applied at temperatures above 140°F [60.0°C] up to and including 175°F [79.4°C] and/or for simultaneous heating/cooling operation (high temperature hot water).
Indirect Fired Package: This type of package reconcentrates the absorbent from heat energy from steam or hot water.
Integrated Part-Load Value (IPLV): A single number part-load efficiency figure of merit calculated per the method described in this standard at Standard Rating Conditions.
Low Pressure Steam: Steam pressures 15.0 psig [103 kPa] and below.
Net Cooling/Heating Capacity: The net cooling/ heating capacity is considered as the usable capacity to the user's system.
Net Heat Reclaim Capacity: A quantity defined as the mass flow rate of the condenser water multiplied by the difference in enthalpy of water entering and leaving the heat reclaim Condenser, Btu/h [kW].
Net Refrigeration Capacity: A quantity defined as the mass flow rate of the evaporator water multiplied by the difference in enthalpy of water entering and leaving the evaporator, Btu/h or tons [kW].
Non-Standard Part-Load Value (NPLV): A single number part-load efficiency figure of merit calculated per the method described in this standard referenced to conditions other than IPLV conditions (for units that are not designed to operate at Standard Rating Conditions).
Part-Load Value (PLV): A single number figure of merit expressing part-load efficiency for equipment on the basis of weighted operation at various partial load capacities for the equipment.
Power Input per Capacity: A ratio of the Total Power Input to the unit, in kW to the Net Refrigerating Capacity at any given set of Rating Conditions, expressed in kW/ton [kW/kW].
Published Ratings: A statement of the assigned values of those performance characteristics, under stated Rating Conditions, by which a unit may be chosen to fit its application. These values apply to all units of like nominal size and type (identification) produced by the same manufacturer. The term Published Rating includes the rating of all performance characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufacturer, at stated Rating Conditions.
Rating Conditions: Any set of operating conditions under which a single level of performance results and which causes only that level of performance to occur.
Simultaneous Heating/Cooling Mode: Operational mode of a Direct-Fired absorption chiller/heater whereby chilled water and hot (heating) water are produced at the same time.
Standard Rating: A rating based on tests performed at Standard Rating Conditions.
Standard Rating Conditions: Rating Conditions used as the basis of comparison for performance characteristics.
Water-Chilling Package: A factory-made and prefabricated assembly (not necessarily shipped as one package) of one or more compressors, Condensers and evaporators, with interconnections and accessories, designed for the purpose of cooling water. It is a machine specifically designed to make use of a vapor compression refrigeration cycle to remove heat from water and reject the heat to a cooling medium, usually air or water. The refrigerant Condenser may or may not be an integral part of the package.
All terms follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning and Refrigeration unless otherwise defined in this section.