NHS Trust

Year: March to August 2020
Location: Somerset, UK
Sector: Healthcare
Service delivered: Project management support


The Covid-19 pandemic put a huge strain on the NHS in the second quarter of 2020, particularly on the clinical side. However, estates teams were equally stretched re-equipping wards, upgrading technical services, and constructing temporary facilities in preparation for the anticipated influx. This pulled resources away from routine, non-Covid estate projects.

ClearLead were asked to support an NHS Trust by project-managing the replacement of a failed chiller. The work was originally scheduled for Easter 2020, but when the chiller (manufactured in Italy) became unavailable owing to Italy’s lockdown, an urgent alternative was required prior to the onset of warm spring weather.

The failed chiller served the block incorporating the Trust’s main Covid-19 wards. With the increased use of ventilators and the extra PPE required, adequate ventilation and cooling was critical to help minimise viral spread and prevent overheating of clinical areas.

ClearLead’s contribution

We reviewed the sizing of the original chiller (575kW). Using hourly weather data from 2019 combined with hourly chilled water flow and return temperatures From this we established that, at an ambient temperature of 33.5oC (i.e. nearly design conditions), the actual chiller load was ~360kW, making the original chiller at least 50% oversized. We therefore concluded that a chiller with a capacity of ~400kW would be sufficient.

As the chiller would need to be craned into position, weight was critical. The failed chiller was ~5Tonnes, so we knew that a replacement of a similar weight would not require any additional structural calculations. Space was also limited due to the presence of adjacent AHU equipment.

Once a suitable and available chiller was identified, ClearLead addressed the installation issues. Since construction, a new Sterile Services Department (SSD) building had been built adjacent, meaning the closest a crane could now be sited was ~45m horizontally from the chiller’s location. As the chiller enclosure was four storeys up, the lifting arm of the crane needed to be ~65m long, requiring the use of one of the largest cranes in the region, weighing over 150Tonnes (including balance weights). A major concern was therefore whether the car-park where the crane was to be sited could safely bear this weight.

ClearLead commissioned a ground pressure study to veri-fy the location of all underground services – drains, pipe-work and cables – using Ground Penetrating Radar (GPR). Armed with this survey data we worked closely with the lifting contractor to agree the exact location needed for the load dispersing pressure mats on which the crane’s outriggers would be sited.

Before installation, we coordinated preparation of the necessary risk assessments covering all facets of the work including mechanical and electrical disconnection and reconnection work on the roof (including CDM), lifting, traffic management, IT communications, air ambulance restrictions and the potential impact on clinical functions during this busy period. As the extract ventilation from the Covid wards discharged near the chiller, staff working on the roof required a very high level of PPE and a decontamination module was commissioned to collect, clean and safely dispose of contaminated PPE.

With the hospital in full operation, clinicians agreed to a window of two hours when the chiller lift could take place. During this time, key areas would be vacated including the SSD which would result in a pause in essential supplies of clean instruments and equipment to the hospital.

The outcome
The installation went according to plan and the chiller was online later the same day. On completion the client said:
I would like to thank you all for your support with the chiller pro-ject. Any project on a live site is challenging but with the added risk of 5 tonnes 50 metres in the air we had to plan this project meticulously. I’m sure you will all agree that the project ran extremely smoothly with all 3 lifts completed within 30 minutes and the total down time for the building and SSD reduced to an hour.