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Throughout the Covid-19 pandemic, facilities managers may have had to shut their plant off due to empty premises. Your Chillers, Heat Pumps and Air Handling Units may need some extra maintenance before reopening sites to ensure they're in top condition, and working effectively.
See our 5 point checklists on how to maintain your AHU's and Chillers/Heat Pumps below:
Tips for recommissioning Air Handling Units
- Leave the power on to the unit but disable any BMS run signals, this uses minimal power but ensures no settings are lost and helps with protecting the unit against frost by monitoring water temperatures and exercising valves and pumps when required.
- Ensure shut off dampers to the building are shut if the unit is stopped from running, this is so no warm air can rise up from the building and condensate in the AHU causing water damage and potential electronic failures.
- Spin fan impellers & thermal wheel by hand once a week to prevent flat-spotting of bearings which could cause a bearing failure on restart after some time dormant.
- Leave the buildings boilers on where possible so when the AHU needs hot water to protect its heating coils it has it available, ensure chilled water coils have adequate anti-freeze protection in them. Where you do shut down boilers it is recommended to drain the water system down so there is no water in present that could freeze and burst any coils or pipework.
- Before restarting any plant after prolonged periods of down time, a thorough check should be carried out by a qualified and competent person.
Tips for recommissioning Chillers and Heat Pumps
- Inhibit operation via BMS or local control but leave the power on – Most compressors will incorporate a heater that ensures no liquid refrigerant in the oil which could damage the compressor on start-up / The machine may have an internal low ambient or water management control strategy which would need to remain active especially in winter months.
- Confirm the compressor heaters are active – In the Off state, each compressor body should be warm to the touch where the heater is installed at the oil sump. Be sure not to touch the heater directly.
- Ensure adequate anti-freeze protection – Still water will freeze quicker in low ambient temperatures. Confirm you have a suitable level of Glycol in your water circuits exposed to low ambient conditions and ensure any means of external temperature/pump management or trace heating control is working correctly.
- Keep on top of your water treatment – Still water can further promote the growth of bacteria and corrosion within your system. Regularly check and clean any water strainers and maintain dosing regimes.
- Before restarting any plant after prolonged periods of down time, a thorough check should be carried out by a qualified and competent person.
To book a service appointment for your AHU, Heat Pumps or Chillers, get in contact with us here.
