How to Extend the Lifespan of Roof-Mounted Units Through Maintenance?

How to Extend the Lifespan of Roof-Mounted Units Through Maintenance?

Daily maintenance of rooftop units should follow the principle of “regular inspections + seasonal maintenance.” Proper upkeep can extend equipment lifespan from 8-10 years to 12-15 years while reducing failure rates by 30%-40%. Core maintenance must cover four key areas: cleaning, inspection, lubrication, and adjustment, with clear schedules established quarterly, semi-annually, and annually.

Quarterly Maintenance (Every 3 Months) focuses on “cleaning and basic inspection,” with emphasis on heat exchangers and filters. First, clean the condenser (outdoor unit) by blowing compressed air (0.5-0.6MPa pressure) from the inside out to remove dust, leaves, and debris from the fins (if stubborn grime persists between fins, soak with a neutral cleaner before rinsing) to ensure unobstructed fins. Next, clean the air filter (indoor side). Remove the filter and rinse with clean water (replace if using a paper filter). Allow it to dry completely before reinstalling to prevent dust from entering the evaporator and reducing heat exchange efficiency. Finally, inspect the electrical system. Tighten all wiring terminals (use a screwdriver to secure any loose connections to prevent overheating from poor contact). Check for aging insulation on wires (if cracks appear, wrap with electrical tape or replace the wire).

Semi-annual maintenance (every 6 months) requires “thorough inspection and lubrication,” focusing on moving parts and seals. First, inspect the compressor: measure winding insulation resistance with a multimeter (normal value ≥2MΩ; if below 0.5MΩ, dry or replace compressor). Check compressor housing temperature (normal operating range 70-90°C; if exceeding 100°C, inspect refrigerant charge or condenser heat dissipation). Next, inspect the fan. Lubricate the fan bearings (apply No. 3 lithium-based grease, filling 1/3 to 1/2 of the bearing volume to prevent overheating from excessive grease). Check the fan impeller for deformation (if deformed, correct or replace to prevent operational vibration). Finally, inspect seals: check refrigerant pipe joint gaskets for aging (replace if hardened) and condensate drain pipe connections for leaks (reapply sealant).

Annual Maintenance (once per year) requires “System Inspection and Performance Calibration,” recommended to be performed by qualified professionals. First, conduct refrigerant system inspection: recover refrigerant using a recovery machine, clean the dry filter (or replace the filter element), re-evacuate the system (vacuum ≤ -0.1MPa, hold for 4 hours), then charge refrigerant to the standard amount, ensuring precise refrigerant charge (deviation not exceeding ±5%); Next, perform heat exchange efficiency testing: measure the evaporator inlet/outlet temperature difference during cooling (normal range: 8-12°C) and the condenser inlet/outlet temperature difference (normal range: 15-20°C). If temperature differences are too low, inspect the heat exchanger for scaling and acid-wash if necessary. Finally, calibrate the control system: adjust temperature sensor accuracy (compare with a standard thermometer; calibrate if error exceeds ±1°C), and test safety protection devices (e.g., high-pressure protection, overload protection; must shut down normally after manual triggering).

Additionally, seasonal maintenance should be performed in advance: Before summer startup, inspect the condensate drainage system (ensure unobstructed drainage to prevent leaks during rainy seasons) and clean the condenser (to enhance heat dissipation efficiency for summer high temperatures). Before winter startup, inspect the electric auxiliary heating function (test if it activates normally and check wiring connections for tightness), and examine insulation layers (replace damaged insulation to prevent cooling/heating loss). During extended shutdowns (e.g., holidays), disconnect power, clear debris from inside and outside the equipment, and place desiccants around the base to prevent moisture damage and aging.