Mill Court Chiller Replacement

Sector

Pharmaceutical

Location

Macclesfield, UK

Services

Structural Engineering

Completion

September, 2025

OVERVIEW

The Mill Court Office Building project involved the structural assessment and upgrade of an existing rooftop plant room to facilitate the replacement of an ageing chiller system with a new, significantly larger and heavier ammonia chiller.

Our scope included reviewing the existing portal frame structure and composite metal deck floor construction to determine its suitability for the proposed installation. The works formed part of a wider building services upgrade aimed at improving the efficiency and reliability of the building’s cooling infrastructure

THE CHALLENGE

The proposed ammonia chiller introduced substantially higher loads to the existing plant room floor structure compared to the original installation. In addition, the wider footprint of the new equipment meant the existing concrete support plinths were no longer suitable.

There was also concern that removing or altering the existing plinths could damage the composite roof slab and disrupt the operational building below.

A robust structural solution was therefore required to safely distribute the increased loads while minimizing intervention to the existing structure.

OUR SOLUTION

A detailed structural assessment was undertaken to verify the capacity of the existing steel frame and composite slab system.

To avoid direct loading onto the roof slab and eliminate the need to remove the existing concrete plinths, a supplementary steel support frame was designed to transfer the chiller loads directly onto the primary structural steelwork.

This approach provided a safe, practical, and cost-effective solution, enabling the successful integration of the new plant equipment while protecting the integrity of the existing building structure.