RACA Journal March 2024 RACA_March_2024_digital | Page 42

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Support
• Examine heater safeties
• Check ducting seals / collars and access door seals hinges , locks .
• Check corrosion
• Examine other accessories ( if applicable )
• Complete logbooks
As always , follow the manufacture recommendations and do not perform maintenance tasks you are not experienced with or trained on .
COMMON PROBLEMS ENCOUNTERED WITH AHUS INCLUDE :
• Fan motor malfunction : Faulty fan motors can lead to inadequate air circulation , reduced airflow and compromised temperature control .
• Coil fouling : This involves the accumulation of dirt , dust and debris on the evaporator and condenser coils . This can decrease heat transfer efficiency , resulting in poor performance .
• Leakage and ductwork issues : Damaged or poorly sealed ductwork can lead to air leaks , decreased efficiency , and inefficient air distribution .
• Belt and pulley problems : Worn-out or misaligned belts and pulleys can cause excessive noise , reduced airflow , and increased energy consumption .
• Control system failures : Faulty sensors , malfunctioning thermostats , or issues with the control panel can disrupt the AHU ’ s operation .
• Air filter issues : Clogged or dirty air filters can obstruct airflow , leading to reduced system efficiency and poor indoor air quality .
• Blocked drains .
The frequency of maintenance for air handling units depends on several factors , including your specific system requirements , manufacturer guidelines and environmental conditions . As a general rule , AHUs should undergo maintenance at least twice a year . This preventive maintenance schedule helps ensure optimal performance , energy efficiency and prolongs the lifespan of the unit . The ideal maintenance frequency is based on specific requirements and usage patterns .
Aisha , I hope that this increases your understanding of air handling units .
Thanks to everybody for the overwhelming response . I receive an average of over sixty questions per month and cannot publish all of them . But keep them coming , as I may answer you directly . Looking forward to hearing from you . RACA
Grant Laidlaw
REFERENCES
1 .
SETA training
2 .
ASHRAE
3 .
ACRA

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RACA Journal I March 2024 www . refrigerationandaircon . co . za