Daikin WHT – Daily Chiller Maintenance Procedure

Use this checklist to inspect Daikin WHT vapor absorption chillers daily for optimal operation and reliability.

General System Overview

  • Visual inspection of entire absorption chiller system for leaks, corrosion, or physical damage
  • Record total operating hours and solution pump starts for maintenance schedules
  • Verify all alarms (temperature, pressure, level, vacuum) are functional and audible
  • Check proper labeling and warning signs for chemical hazards
  • Inspect insulation integrity on all vessels and piping

Absorption Solution System

  • Check lithium bromide solution level in absorber sump
  • Verify solution concentration using refractometer (54-64% typical)
  • Monitor solution temperature at various points in cycle
  • Check for crystallization indicators or solution clouding
  • Verify solution pump operation - no cavitation or unusual noise
  • Check solution flow rates and differential pressures

Heat Source System

  • Verify steam/hot water supply temperature and pressure
  • Check steam trap operation and condensate return (if applicable)
  • For direct-fired units.
  • Monitor generator temperature and pressure within specifications
  • Inspect heat input control valve operation and response
  • Verify exhaust gas temperature (direct-fired units)

Vacuum & Purge System

  • Check system vacuum level - typically 6-10 mm Hg absolute
  • Monitor purge unit operation and runtime
  • Check for excessive purge activity indicating air leaks
  • Verify purge pump oil level and condition
  • Test vacuum relief valve for proper seating
  • Check all vacuum gauge readings for accuracy

Water Systems

  • Verify chilled water flow rate and temperature differential
  • Check cooling water flow through absorber and condenser
  • Monitor approach temperatures in heat exchangers
  • Verify water treatment chemical levels and dosing
  • Check for proper venting of water boxes
  • Inspect strainers and filters for cleanliness

Control System & Display

  • Daikin control panel display functional and clear
  • No active alarms or fault messages present
  • Verify all operating setpoints are correct
  • Check trending data for abnormal patterns
  • Test manual override functions
  • Verify remote monitoring connectivity (if applicable)

Refrigerant Water Circuit

  • Check refrigerant (water) level in evaporator
  • Monitor refrigerant pump operation and flow
  • Verify proper spray pattern over evaporator tubes
  • Check for refrigerant contamination or discoloration
  • Monitor evaporator temperature and pressure

Safety & Protection Systems

  • Test all safety interlocks and shutdown systems
  • Verify crystallization prevention system operation
  • Check emergency dilution system readiness
  • Test high temperature cutout switches
  • Verify proper ventilation in equipment room
  • Check safety shower and eyewash station functionality

Performance Monitoring

  • Calculate and record coefficient of performance (COP)
  • Monitor cooling capacity vs.
  • Track heat input consumption and efficiency
  • Review cycle temperatures for optimization opportunities
  • Document all operating parameters in log
  • Compare current performance with baseline data