Complete AHU replacement isn’t always necessary or practical. Component upgrades can dramatically improve efficiency of existing equipment at a fraction of replacement cost.
Why Upgrade Components?
Extend Service Life
Upgrading worn or inefficient components extends the useful life of the complete unit.
Improve Efficiency
Modern components are significantly more efficient than those from even ten years ago. Upgrades deliver ongoing energy savings.
Enhance Performance
Upgraded components can improve performance – better control, lower noise, increased capacity.
Reduce Maintenance
New components reset the maintenance clock. Fewer breakdowns and lower repair costs.
Component Upgrade Options
Fan Upgrades
Fans are typically the largest energy consumers in AHUs. Upgrade options include:
EC Fan Replacement – Electronically commutated fans are dramatically more efficient than AC alternatives, particularly at part load. Typical savings of 30-50% on fan energy.
Plug Fan Conversion – Replace housed centrifugal fans with plug fans. Better efficiency, lower noise, reduced maintenance.
Impeller Upgrade – Modern aerodynamic impeller designs improve efficiency within existing housings.
Motor Upgrades
Where complete fan replacement isn’t practical, motor upgrades offer improvements:
IE3/IE4 Motors – High-efficiency motors reduce losses compared to older designs.
Correct Sizing – Oversized motors operating at low load are inefficient. Right-sizing improves efficiency.
Variable Speed Drives
Adding VSDs to constant speed fans enables speed control. Running fans at reduced speed when full capacity isn’t needed saves substantial energy.
VSDs also provide soft start, reducing mechanical stress and electrical demand on start-up.
Controls Upgrades
Modern controls enable strategies that older systems can’t support:
Demand-Controlled Ventilation – Vary ventilation with occupancy for significant savings.
Optimised Sequences – Better control sequences reduce energy waste.
BMS Integration – Connect standalone units to building management systems for coordinated control.
Heat Recovery Addition
Adding heat recovery to units without it is often possible. Options include:
Plate Heat Exchanger – Where duct arrangements allow supply and exhaust to pass through a common device.
Run-Around Coil – Where airstreams can’t be brought together. Coils in each airstream connected by a pumped loop.
Coil Replacement
Degraded coils reduce heat transfer efficiency. Replacement options include:
Like-for-Like – Direct replacement restoring original performance.
Enhanced Performance – Improved coils providing better heat transfer or increased capacity.
Material Change – Different materials to resist corrosion or suit changed water conditions.
Filter Upgrades
Improved filtration may be possible within existing housings:
Lower Pressure Drop Filters – Modern filters achieve equivalent filtration with less resistance.
Upgraded Filtration – Higher efficiency filters where air quality requirements have increased.
Upgrade Assessment Process
Survey Existing Equipment
Document current components, condition, and performance. Identify constraints for upgrades.
Establish Objectives
What are you trying to achieve? Energy reduction, performance improvement, extended life, reduced maintenance?
Evaluate Options
Which upgrades address objectives within constraints? What are the costs and benefits?
Design and Specify
Ensure upgraded components are compatible with retained elements. Specify clearly for procurement.
Implement
Careful installation is essential. Upgraded components need commissioning.
Verify Performance
Measure outcomes against objectives. Document achieved improvements.
Practical Considerations
Structural Compatibility
New components must fit existing structures. Check dimensions, weights, and mounting arrangements.
Electrical Compatibility
New motors and drives must work with existing electrical infrastructure. Check supply characteristics and protection.
Control Integration
New components must work with existing controls – or controls must be upgraded simultaneously.
Downtime
Upgrades require the AHU to be offline. Plan work to minimise disruption.
Our Upgrade Services
i-Flow assesses existing equipment and recommends appropriate upgrades. We supply components and can support installation and commissioning. Contact us to discuss your AHU upgrade requirements.
