Top 8 Maintenance Tips for Absorption Chillers

Chill-Pro® supports a comprehensive approach to predictive maintenance that protects the building
owner’s investment in cooling equipment and keeps it operating reliably and efficiently.

Here are 8 Tips for maintaining Absorption Chillers…

1. Maintain the Purge unit
   Perhaps the most critical part of the system’s operation is the purge unit, which maintains the
   vacuum within the chiller shell by expelling air that leaks in. The pump should be operated at
   least once a week, even when the system is not in use.
2. Leak-Test the unit regularly
   Because an absorption chiller system requires vacuum conditions to generate cooling, air leaks
   sharply reduce system performance and reliability. If the system requires frequent purging, it
   should be pressure-tested as soon as possible to check for air leaks. Leaks should be repaired
   promptly.
3. Test for tube leaks
   If leaks are detected at the head of the generator, evaporator, condenser, or absorber, there
   may be a leak in one of the tubes. Pressure tube testing or eddy current testing can be used.
   Replace faulty tubes as necessary.
4. Check for tube fouling and scaling
   A drop in capacity may indicate that the tubes need to be cleaned. Cleaning frequency is
   influenced by local water characteristics, atmospheric contamination, operating conditions, and
   other local conditions. Two types of deposits can cause fouling: Dirt/rust/ sludge, and scale.
   Condenser tubes should be cleaned annually, at a minimum.
5. Maintain the pumps
   Seals on both solution and refrigerant pumps should be replaced when a leak is evident. The
   motor coolant system strainer should be cleaned while other maintenance functions are being
   performed.
6. Make sure the lithium bromide is properly conditioned
   For maximum protection, the system must have the proper lithium bromide salt concentration
   and inhibitor to prevent the salt solution from causing internal corrosion on the shell and tubes.
   Withdraw and test a sample of the salt solution and consult the manufacturer if alkalinity is too
   high.
7. Inspect and verify the calibration of controls
   Check all operating and safety controls, checking lights and gauges for accuracy. Inspect steam
   valve and make sure it is closing properly. Check power supply and unit fuses. Review the
   temperature readings on the cooling tower water. Check the settings of tower fans.
8. Maintain a Data log
   A good log may help an operator recognize early symptoms that could result in poor
   performance or damage to the unit.