The West Suffolk Hospital NHS Trust is located in Bury St Edmunds, Suffolk.

The heating demands of the Site were originally served by 4No. 1.8MW boilers, each located in its own rooftop plant room. In 1993, one of the boilers was removed and replaced with a 300kWe CHP and absorption chiller plant. At the same time, the capacity of each of the remaining boilers was de-rated to 1.2MW.

Much of the heat generation plant at the Site was original and nearing the end of its’ economic life. In addition, due to the continued programme of expansion at the Hospital, the Plant was running at, or near to its rated capacity, which meant that there was no provision for standby in the winter months. A third emergency generator was also required at the Hospital, and a new Combined Heat and Power (CHP) Plant was proposed to achieve the extra heat capacity and also act as a supplementary generator. A series of pipework and controls modifications were also made to the Hospital system and the boiler burners were replaced with new larger units.

JSH were responsible for designing and Project Managing the installation.

The Main Contractor for the Project was Southern Electric Contracting (SEC) and the cost was £1.2M.

The CHP was sized to match the specific heating and power requirements of the Site and the nominal capacity of the unit was for 800kWe and 1.145MWth.The CHP  plant  was  located  externally  in  its’  own weatherproof enclosure, immediately adjacent to the existing standby generators and is connected to the hospital   heating   ring -main, (which  operates  at  a temperature of 82°C flow and 71°C return), the incoming electricity supply (via G59 protection) and the standby generator control panel.

The base heating and power requirements of the Site were calculated to be in the order of 300kWth (occurring in July/August) and 450kWe (daily at 9-10pm) respectively. Accordingly, an air-blast cooler was installed on the flat roof adjacent to the CHP to ensure that the unit would be able to run consistently throughout the summer months (to serve the Trust’s absorption chiller plant) and also at its’ full power (irrespective of the time/season) should it be called into operation during a mains outage at the Site.

Alterations and improvements were also carried out to  the  Hospital’s  BMS installation to ensure that all the new plant and equipment could be effectively managed to maximise savings from the Scheme.

The CHP Plant was provided with its’ own control system for successful and efficient operating of the CHP. The  CHP  supplier  also  allowed for a modem for the remote monitoring of the unit.

The BMS Control Specialist installed sensors to monitor the running of the CHP Plant, the temperatures of both the flow and return water and all heat metering equipment.

The unit is programmed to run 17 hours per day 365 days per annum (less serving and maintenance). The Trust has a Servicing and Maintenance Agreement with Dresser-Rand that guarantees an availability of 92%.

Savings generated by the Scheme are made up as follows:

The above savings are based on gas and electricity unit prices as at September 2009.
The Scheme, also affords approximately 650tonnes of reduced CO2 emissions to the Trust, which contributes to its’ wider environmental agenda.