CASE STUDY: Restoring Pack Stability on an Exposed Rooftop Site

CHALLENGE

Thermal Load Risks and Performance Disruption

At Waitrose Wimbledon, two rooftop refrigeration packs were exposed to prolonged sun exposure, with no natural shading and limited ventilation due to their position within a parapet enclosure. 

As temperatures rose, system strain increased, pushing components beyond optimal thresholds and triggering recurring operational faults. On more than one occasion, this contributed to temporary disruption at the store.

The location added complexity. Positioned next to an active trainline and enclosed on the rooftop, the packs required careful planning and extra safety precautions to ensure safe, non-disruptive access.

The aim was to reduce solar heat gain, stabilise system performance, and protect key components, all without compromising airflow or routine servicing access.

APPROACH

Diagnosing the Problem Before Installing the Fix

Epta’s Retrofit team began by reviewing the site conditions and available system data to understand the root cause of the faults.

The issue wasn’t with the packs themselves, it was environmental. With no protection from direct sun exposure, the packs were overcompensating to maintain cooling, increasing wear and driving load-induced strain.

A tailored solution was developed. A lightweight Unistrut frame was installed without ground fixings, anchored to approved rooftop supports. The design preserved full 2 m access clearance and worked around existing services.

Purpose-selected shading netting, chosen for its muted, functional aesthetic, was then suspended from the frame, dropping 1.5 m down each side, with raised corners to support clear sightlines and easy servicing.

The result was a stabilised rooftop environment, reduced thermal pressure, and improved operational consistency.

PROJECT HIGHLIGHTS

Targeted Design. Tangible Results.

• Site-specific solution adapted to rooftop layout

• No ground penetration – structure anchored to existing supports

• Shading netting reduced solar gain without blocking airflow

• Clear access for servicing maintained

• Extra planning carried out due to trainline proximity

• Improved system stability and no recurring faults reported

OUTCOME

Uptime Restored And Confidence Rebuilt

Since installation, system performance at the site has remained stable. The rooftop packs are no longer exposed to the same levels of sustained thermal stress, and no further shutdowns have been reported.

By tackling the source of the strain, solar heat gain, Epta helped extend pack longevity, reduce callouts, and avoid disruption.

This intervention reflects our wider Retrofit approach which included assessing the issue, tailoring the response, and quietly delivering improvements that protect uptime and store operations.

"We recently had a solar shade installed over the refrigeration packs at our Waitrose located in Wimbledon, and we couldn't be happier with the results.
The team from Epta's Retrofit department, led by Patrick Liptrott, handled everything from start to finish with professionalism and a can-do attitude.
The install was smooth and straightforward – even when small challenges came up, the team took them in stride and kept everything on track.
Since the installation, we've seen a noticeable reduction in pack load, fewer breakdowns, and less downtime – which ultimately means cost savings and more reliable service for our customers. A great experience all around!"

- Michael Platt, Oaksmere

What's Next?

Epta’s Retrofit team continues to help retailers tackle performance risks across exposed rooftop and plant installations. From heat gain and layout constraints to service access and regulatory barriers, our approach begins with diagnosis, and ends with fixes that make systems more stable, reliable, and resilient.

Get in touch with Patrick Liptrott at

Mobile: 07500 227 673

Email: patrick.liptrott@epta-uk.com