1. Selection Guide for Heating and Cooling Source Equipment
Heating and cooling source equipment is the core of the hotel MEP system, and selection is based on GB 50736-2012. Selection steps: calculate the cooling and heating loads using the hourly load calculation method or the budget estimate index method; hotel cooling load index 80-120 W/sqm, heating load index 60-100 W/sqm; determine the chiller type: centrifugal for large units greater than or equal to 500 RT, screw for medium units 200-500 RT, scroll for small units less than 200 RT; energy efficiency selection: COP greater than or equal to 6.0 for centrifugal chillers at Grade 1 energy efficiency, or greater than or equal to 5.2 for screw chillers at Grade 1 energy efficiency; IPLV greater than or equal to 8.5 for centrifugal or greater than or equal to 7.5 for screw. Refrigerant selection: low-GWP refrigerants such as R134a/R1234ze/R32. Quantity configuration: n+1 redundancy principle, with single-unit capacity less than or equal to 60% of total capacity.
2. Selection Guide for Pumps and Fans
Pump selection is based on GB 50265-2010. Selection factors: flow rate selected at 1.1 times the system design flow rate; head = resistance of the most unfavorable loop plus equipment resistance plus safety margin of 10%-15%; pump type: chilled water and cooling water pumps as horizontal end-suction centrifugal pumps or vertical inline pumps, hot water pumps as heat-resistant type; energy efficiency greater than or equal to the energy-saving evaluation value in GB 19762-2007, with highest efficiency when specific speed ns is in the range of 100-200; VFD configuration: frequency converters recommended when motor power is greater than or equal to 15 kW. Fan selection is based on GB/T 1236-2017. Selection factors: air volume calculated according to room air changes and supply air temperature difference; total pressure overcomes duct resistance plus equipment resistance plus outlet dynamic pressure.
3. Selection Guide for Air-Conditioning Terminal Units and Valves
Air-conditioning terminal unit selection: air handling units (AHU) classified by function as primary return air, secondary return air, and 100% fresh air; cooling coil rows 4-8; air volume range 5,000-80,000 CMH; external residual pressure 200-600 Pa; fresh air handling units (PAU) handle the fresh air load and are equipped with heat recovery devices: rotary wheel, plate, heat pipe; heat recovery efficiency greater than or equal to 60%; fan coil units (FCU) used in guest rooms and office areas, by model 2-row or 3-row coils, air volume 340-2,380 CMH. Valve selection guide: types: gate valves for full open/full close service, globe valves for throttling service, butterfly valves for large-diameter on/off service, balancing valves for hydraulic balancing, electric control valves for automatic control; size: same as pipe diameter or one size smaller; control valves should preferably be one size smaller to improve control performance.
4. Selection Guide for Piping and Insulation Materials
Piping selection: air-conditioning chilled/hot water pipes DN less than or equal to 50 mm use galvanized steel pipes with threaded connections; DN greater than or equal to 65 mm use seamless steel pipes with welding or spiral welded pipes; condensate drain pipes use UPVC pipes or galvanized steel pipes, laid according to drainage slope; cooling water pipes DN greater than or equal to 100 mm recommend GRP (glass-reinforced plastic) pipes or anti-corrosion-treated steel pipes; fire protection water pipes use internally and externally hot-dip galvanized steel pipes with grooved connections or flange connections. Insulation material selection: air-conditioning cooling pipes use rubber-plastic sponge, closed-cell structure, with integral vapor barrier, thermal conductivity less than or equal to 0.039 W/(m*K), Class 0, B1 flame retardant, applicable temperature -40 degrees to 105 degrees; air-conditioning heating pipes use glass wool or rubber-plastic, thickness calculated according to medium temperature; duct insulation uses rubber-plastic board or glass wool board plus vapor barrier.