Chiller Selection and Configuration Standards
According to GB 50736 Section 7.2 and GB 50189 Section 5.2, the selection process is as follows: Step 1: Determine installed capacity—based on hourly load calculations, multiply the design cooling load by 1.1 to determine total installed capacity. Step 2: Select unit type—for single-unit capacity greater than 1500 kW, prioritize centrifugal; for 500-1500 kW, select screw or magnetic bearing; for less than 500 kW, select scroll. Marriott MIDS requires COP not less than 6.3. Step 3: Determine number of units and ratio—recommended 3 units of different capacities (40%+30%+30%), with optimal combination selected through group control. Step 4: Refrigerant selection—refrigerants with GWP greater than 2500 shall not be used; R134a (GWP=1430) is being replaced by R513A (GWP=631). Step 5: Brand selection—international brands Trane, Carrier, York, Daikin; domestic brands Gree, Midea, Haier. Auxiliary equipment configuration: each unit equipped with independent variable-frequency chilled water pump and cooling water pump; cooling towers selected at 1.2 times capacity; supporting water treatment devices.
Air-conditioning Terminal Equipment Selection and FCU Configuration
FCU selection factors: airflow, cooling capacity, noise, external static pressure. Guest room FCUs selected by airflow rating: standard room (40 m²) uses 400 CFM; suite (60 m²) uses 600 CFM. Cooling capacity verified against design load with margin not exceeding 15% to avoid oversized selection affecting dehumidification. Regarding noise, GB 50118 requires guest room nighttime noise not exceeding 30 dB(A); EC brushless DC motor FCUs are recommended, with noise 3-5 dB(A) lower. AHUs used for large spaces such as lobbies and ballrooms; selection determined by three parameters: airflow + cooling capacity + external static pressure; equipped with heating section, cooling coil section, humidification section, filtration section (G4+F7). PAUs equipped with heat recovery section; selected by fresh air volume: guest room area 50 m³/(h·room); public areas calculated by occupant density. General selection principle: equipment parameters must fully match system design parameters; large temperature difference schemes require FCU re-verification. Terminal positioning must consider maintenance space—reserve not less than 300 mm above FCU; reserve not less than duct width + 600 mm in front of AHU.
Power Supply and Emergency Generator Equipment Selection
Transformer selection—hotels use dry-type transformers (SCB series), typically one 1250-2000 kVA unit per 6000-8000 m². A 50000 m² five-star hotel has installed capacity of approximately 6000-7500 kVA, with 4 units of 1600-2000 kVA, load rate 65%-75%. SCB13 type reduces no-load loss by 20% compared to SCB10 type. Emergency generator selection—determined by the sum of fire protection load + essential load; for five-star hotels typically 15%-20% of total transformer capacity (approximately 1000-1500 kW). Marriott MIDS requires simultaneous operation of fire protection load + 50% essential load, with fuel tank capacity for 3 hours. Diesel generator noise not exceeding 85 dB(A) at 1 m from machine room; sound attenuation devices required. UPS equipment—provides backup power for weak-current machine rooms and fire control rooms for not less than 30 minutes (Marriott requires not less than 60 minutes); lithium battery UPS recommended, saving 60% floor space and 2 times longer service life.
Water Supply, Drainage and Fire Protection Core Equipment Selection
Domestic water pump selection—variable-frequency constant-pressure water supply units; flow determined by maximum daily water consumption (five-star hotel 500-600 L/room·d); configured as 2 duty + 1 standby. GB 50015 requires pumps to operate in high-efficiency zone; variable frequency 25-50 Hz. Hot water circulation pumps—circulation flow determined to ensure hot water delivery within 5 seconds, at 30%-50% of design hot water consumption; PID regulation based on return water temperature. Hot water boilers—gas-fired vacuum hot water boilers recommended (efficiency not less than 95%); configured as 2 units at 60% or 3 units at 40% capacity. Fire pumps—hydrant pumps selected at 20-40 L/s; sprinkler pumps selected at 30-50 L/s; 1 duty + 1 standby. GB 50974 requires self-priming suction; motor power not less than 110% of design power. Storage tanks—volume determined by 15-20 minutes of design hourly heat consumption; stainless steel 304 or 316L material. Water treatment equipment includes automatic water softeners, electronic descaling devices, ultraviolet sterilizers.