Cooling tower refurbishment in Central London, delivering improved performance, compliance and long-term reliability without full replacement.
Read below to see one of Vistech's recent success stories:
The site comprised two ageing Visco cooling towers serving a high-value London commercial property. The towers were originally constructed with:
316 stainless steel casing
Mild steel centrifugal fans
Gravity-fed distribution
Ageing packing and drift eliminators
While structurally sound, performance and compliance standards had evolved. The towers required upgrading to meet revised duty requirements without full replacement.
In Central London, traditional replacement would have introduced significant logistical challenges:
Road closures and cranage
Structural loading reviews
Pipework re-routing
Control system modifications
Programme disruption
The client required a refurbishment partner capable of upgrading non-Vistech towers, working within tight urban constraints, and delivering a long-term engineered solution.
The project required:
Upgrade from gravity distribution to spray system
Replacement of pack and drift eliminators to anti-legionella standard
Improved access and maintainability
Replacement of fans with high-efficiency stainless assemblies
Installation of safe internal working platforms
Minimal external disruption
Sequential works to maintain site resilience (one tower at a time)
Additionally, the solution needed to comply with ACOP L8 and HSG274 guidance while enhancing long-term reliability.
The existing cooling towers were required to meet an updated duty, necessitating improved heat rejection performance without full system replacement.
The ageing gravity-fed distribution system required replacement with a modern spray system to improve water coverage, efficiency and overall cooling performance.
Packing and drift eliminators required upgrading to high-efficiency anti-legionella components to meet ACOP L8 and HSG274 compliance standards.
The system required enhanced internal access to enable safe inspection, cleaning and long-term maintenance in line with best practice guidance.
Existing mild steel fan assemblies required replacement with stainless steel, high-efficiency units to improve reliability, durability and energy performance.
The refurbishment needed to be completed without cranage, road closures or major structural modifications, minimising disruption within a high-value London site
Vistech delivered a complete engineered refurbishment of both towers, demonstrating our capability to modernise and upgrade towers manufactured by other OEMs.
The existing mild steel centrifugal fan units were removed and replaced with:
316 stainless steel split casings
316 stainless steel DIDW impellers
Precision-ground stainless shafts
Auto-lubrication systems
Siemens IE4 high-efficiency motors
Split casings allowed roof manoeuvring without cranage — critical in a Central London environment.
The ageing gravity system was replaced with a high-efficiency spray distribution system constructed from:
GRP reinforced uPVC
Stainless steel fittings
This improved water distribution uniformity, increased thermal performance and supported the increased pack depth
New modular 12mm flute anti-legionella PP packing (800mm depth) was installed.
Benefits included:
Lower pressure drop
Easy removal for inspection (aligned with HSG274 Pt1 guidance)
Self-supporting welded construction
Long-term UV and chemical resistance
New stainless-framed cellular eliminators were installed with:
<0.0005% drift loss
T-bar air seals to prevent bypass
Closed-cell design maximising droplet capture
ACOP L8 compliance
To improve safety and maintainability:
GRP Cleansafe flooring installed beneath pack
New stainless steel access doors added
Sump doors replaced and resealed
Horizontal casing joints split and re-masticed
This created a safe internal maintenance platform and extended casing service life.
The refurbishment was delivered within a constrained Central London environment, avoiding:
Cranage
Road closures
Structural modifications
Pipework reconfiguration
Split fan casings and modular internals enabled manual roof manoeuvring, reducing programme risk and minimising disruption.
By retaining the existing 316 stainless steel casing, the project avoided unnecessary embodied carbon and extended asset life—while delivering an upgraded system that, in key areas, exceeds typical new galvanised replacement standards.
Rather than replacing plant, Vistech re-engineered critical performance drivers, including:
Air movement efficiency
Water distribution uniformity
Heat transfer capacity
Drift control and compliance
Access, safety and maintainability
Vistech successfully upgraded Visco-manufactured towers, demonstrating our ability to deliver engineered retrofit solutions across multiple OEM platforms.
Our refurbishment approach is not constrained by original manufacturer limitations, enabling performance-driven upgrades tailored to site requirements.
Site mobilisation, isolations and initial strip-out of existing cooling tower internals
Removal of existing fan assemblies, distribution system and redundant components
Mechanical preparation & GRP Lining of casing, surface cleaning and resealing of horizontal joints
Installation of new stainless steel fan assemblies and drive systems
Installation of high-efficiency spray distribution system and pipework modifications
Installation of anti-legionella packing, drift eliminators and cleansafe flooring
Installation of access upgrades, doors, heaters and instrumentation
Commissioning, performance testing and staged handover of cooling tower systems
"Vistech provided a technically sound and commercially pragmatic alternative to full cooling tower replacement. Their ability to refurbish our existing towers within a constrained Central London site significantly reduced programme risk and disruption. The upgraded system has delivered improved performance and confidence in long-term compliance."
The Vistech team are always happy to help with any stage of your cooling system project.
