Every air handling unit will eventually need replacement parts. Motors wear out, bearings fail, coils corrode, and controls become obsolete. How quickly you can source those parts often determines how long your system is out of action.
Understanding the parts supply landscape helps you plan ahead and respond effectively when components fail.
Standard Components
Many AHU components are standard industrial products available from multiple sources. These present few sourcing challenges:
Belts and pulleys are commodity items available same-day from industrial suppliers. Keep common sizes in stock for immediate replacement.
Bearings follow standard sizing conventions. Match the bearing number and order from any bearing supplier. Standard types are always available; specialist bearings may have short lead times.
Filters from major manufacturers have wide distribution. Standard sizes ship immediately. Custom sizes may require a few days.
Contactors, relays, and electrical components are standard industrial controls. Match the specification and source from electrical wholesalers.
Fan motors in standard frame sizes are usually available quickly. Match the frame size, power, speed, and voltage. Motors can often be sourced within days, even for larger sizes.
Manufacturer-Specific Parts
Some components are specific to particular AHU manufacturers. These require sourcing through manufacturer channels or specialist suppliers:
Proprietary controls from the original manufacturer may be the only option. Older control systems become increasingly difficult to source as manufacturers discontinue product lines. Consider controls upgrades before parts become unavailable.
Custom coils sized specifically for your unit may require manufacturer supply or fabrication to match. Lead times of 4-8 weeks are common for replacement coils.
Dampers and actuators may use manufacturer-specific mounting arrangements or control interfaces. Generic replacements sometimes work; otherwise, manufacturer supply is necessary.
Fan assemblies in custom configurations may need matching to original specifications. Standard fan wheels are readily available, but complete assemblies with specific motor mounts or configurations take longer.
Obsolete Components
The real challenge comes when original components are no longer manufactured. Options include:
Direct replacement from the original manufacturer may still be possible for some years after product discontinuation. Stock levels decline over time until nothing remains.
Compatible alternatives from other manufacturers may fit and function correctly. This requires careful specification matching and sometimes minor modifications.
Remanufacturing can rebuild certain components. Motors can be rewound, coils retubed, and mechanical components refurbished. Quality varies with the remanufacturer.
Custom fabrication creates new parts to match original specifications. This works for mechanical components but rarely for electronics.
System modification may allow fitting different components. A skilled engineer can often adapt installations to accept alternative parts, though this adds cost and complexity.
Managing Lead Times
Critical spares stockholding eliminates lead times for components likely to fail. Identify what would cause extended downtime if unavailable, and keep those items on-site. Motors, drives, and control boards are common candidates.
Supplier relationships matter when you need parts urgently. Established accounts with responsive suppliers get better service than one-off enquiries. Know who can help before you need them.
Maintenance data informs spares decisions. Which components have failed before? What’s wearing and likely to need replacement soon? Use maintenance history to predict needs.
Alternative sources provide backup when primary suppliers can’t help. International sourcing, specialist brokers, and used equipment dealers all have roles when standard channels fail.
When to Replace vs. Repair
Sometimes the parts search reveals that replacement of the entire unit makes more sense than continued repairs:
If multiple components are obsolete, each failure becomes a sourcing challenge. The cumulative time and cost of repeated parts-hunting adds up.
If the unit’s design prevents fitting modern alternatives, you’re locked into diminishing supply chains.
If parts costs approach a significant fraction of replacement cost, the economics favour new equipment.
Our Parts Support
i-Flow maintains relationships with component suppliers across the industry. We can source parts for our own units and often help with other manufacturers’ equipment.
For critical applications, we can advise on spares stockholding strategies and supply parts packages for on-site storage.
Contact us if you’re struggling to source AHU parts. We may be able to help directly or point you toward solutions.
