2020 ASHRAE Handbook: HVAC Systems and Equipment

Read from local Zotero full-text PDF (group 5183627 / Joule Heist).

(Reference handbook — HUGE; read TOC plus the central-plant / chiller / cooling-equipment chapters only, ingested as a reference pointer.)

Key findings

• Cooling-relevant chapters: Ch. 3 Central Cooling and Heating Plants; Ch. 38 Compressors; Ch. 39 Condensers; Ch. 40 Cooling Towers; Ch. 41 Evaporative Air-Cooling Equipment; Ch. 42 Liquid Coolers; Ch. 43 Liquid-Chilling Systems; Ch. 48 Unitary Air Conditioners and Heat Pumps; Ch. 37 Solar Energy Equipment.
• Chillers are the major cooling equipment in central plants, falling into two categories: (1) vapor-compression (compressorized) chillers and (2) absorption-cycle chillers. Both require heat rejection via cooling towers, air-cooled condensers, or evaporative condensers.
• Compressorized chillers use scroll, helical rotary (screw), and centrifugal compressors, driven by electric motors, gas/diesel/oil engines, combustion turbines, or steam turbines. Centrifugal compressors are typical in larger packaged chillers; reciprocating and screw units can be field-assembled with remote condensers. Compressor selection depends on capacity, first cost, and life-cycle cost.
• Absorption chillers use a lithium bromide/water cycle (LiBr/water solution is the refrigerant) and are single- or double-effect (double-effect = higher capacity, more efficient, but more input energy). Configurations: natural-gas direct-fired; indirect via low-pressure steam/hot water; indirect via high-pressure steam/high-temperature hot water; indirect via hot exhaust gas — making them well-suited to waste-heat-driven cooling and CHP integration.
• Air-cooled condensers run at higher condensing temperature than water-cooled (using dry-bulb vs wet-bulb), giving higher peak power input; they suit scroll/screw compressors, smaller systems, and cooler climates needing freeze protection, and avoid cooling-tower water use and maintenance.
• Chillers producing colder chilled water generally use more energy on a kW/kW (COP) basis; plant COP is monitored to gauge overall chilled-water-plant operating efficiency.
• Heating-side baseline (Ch. 3): low-pressure boilers rated to 100 kPa steam / 1100 kPa water with a 120 degrees C temperature limit; decentralized unitary HVAC equipment typically under 70 kW per zone; room conditioners use hermetic reciprocating or scroll compressors with capillary tubes.
• Thermal (cold) storage — off-peak chilled-water or ice generation (Ch. 50) — is highlighted as a cost-saving strategy where utilities impose summer peak-demand charges; storage sized for summer can also serve winter heat reclaim.
• Air-cooled room conditioners often ice up and become ineffective when outdoor temperatures fall below ~18 degrees C; multiple-unit (zoned) unitary systems run under 70 kW per zone with factory-charged refrigeration.
• Ch. 37 (Solar Energy Equipment) was updated with new worldwide solar-technology-use data and an expanded photovoltaic section; Ch. 9 added content on waste-heat recovery and industrial process heat pumps.