Handbook of air conditioning and refrigeration / Shan K

● Multizone dual-duct VAV central systems
● Multizone VAV reheat packaged systems
● Multizone fan-powered VAV packaged systems
● Desiccant dehumidification packaged systems
● Evaporative cooling systems
● Two-pipe fan-coil system
● Four-pipe fan-coil systems
● Packaged terminal air conditioner
● Water-source heat pump systems
● Ground-source heat pump systems
● Gas-engine-driven heat pump systems
● Thermal storage systems
Energy Efficiency Measures
Plant
ENERGY MANAGEMENT AND GLOBAL WARMING 25.27
Based on Scientific Computing (1996), the energy use is calculated and analyzed with the following
energy efficiency measures and controls:
● Control of the air leaving coil temperature. Constant, coldest/warmest, reset schedule based on
outdoor temperature, and user-defined reset temperature schedule.
● Air economizer control. No economizer, air economizer actuated by a fixed temperature, air economizer
actuated by comparing outdoor air enthalpy with return air, air economizer actuated by
comparing outdoor air temperature with a fixed temperature, and supply air contains fixed amount
of outdoor ventilation air.
● Type of air-to-air heat recovery. Heat exchanger, rotary wheel, and run-around coils.
● Fan operating schedule and control. Fan is operating according to user-defined schedule; fan control
includes constant-volume, variable-speed fan inlet vanes, discharge damper, cycles on and
off, high and low speeds, as a function of part-load ratio.
Energy simulation of the following heating and cooling plant equipment can be performed either by
performance equations or by physical modeling:
● Boilers include multistage resistance-type electric boilers, gas/oil-fired hot water boilers, and
gas/oil-fired steam boilers. Boilers can be operated only when load is passed from the system, or
in standby operation. Boilers can also be operated at a modified energy input/heat output as a
function of the part-load ratio.
● Single-effect or double-effect direct-fired absorption chiller is used in which the cooling capacity
can be modified as a function of refrigeration load required, or as a function of chilled water temperature
entering the chiller.
● Open and hermetic centrifugal chillers modify the capacity and electric power input as a function
of chilled water temperature entering the chiller, or their part-load ratio.
● Centrifugal chillers are used with double-bundle condensers in which condenser water is used as
the hot water for winter heating in perimeter zone.
● Open and hermetic reciprocating chillers are used with the type of condenser specified, including
air condenser or evaporatively-cooled condenser.