Opal House – an NHS project
Heat Pump reworks at an NHS facility
Situation
Opal House, located on the Wythenshawe Hospital site, is an NHS unit used to house patients awaiting discharge plans to return home. The renewable solution that had been installed by third party supplier was not working and affecting basic care provision.
This system comprised of a hybrid design including a Ground Source Heat Pump (GSHP), one main GSHP, and three high-temperature heat pumps (HP) designed to increase the system output temperature to 60°c.
Unfortunately Opal House suffered a compressor failure and design limitations on the second heat pump and chose to contact Calibrate and Ground Heat, both RSK companies, to work together to diagnose and rectify the problem.
Solution
Getting to the solution proved a complex process. It included several site visits to trouble shoot, and combined this with a thorough review of the installation documentation and collecting and analysing data from the system. It became apparent to our team of specialists that the buffer vessel which suppled domestic hot water (DHW) and heating to Opal House was undersized, and unable to cope with the demand. The system was also imbalanced; the second heat pump was overworked, whilst heat pumps three and four were seldom operational, with heat pump one never in operation. It became apparent to our team of specialists that the buffer vessel which suppled domestic hot water (DHW) and heating to Opal House was undersized, and unable to cope with the demand.
This imbalance led to unnecessary strain on certain mechanical components; with heat pump one never operating, the imbalance was placing excessive pressure on the rest of the system to elevate the water temperature from 10°c to 60°C. This was not only reducing the lifespan of the system, but it was not reliable in producing a safe and comfortable environment for the patients or staff members.
Outcome
Working together, Calibrate and Ground Heat have installed three key modifications to rectify the system and elongate its life span. This included a reconfiguration of the system, with heat pump one, the GSHP, and one of the high temperature heat pumps being rerouted to feed the buffer vessel exclusively for heating. Commissioning valves were installed and placed on each unit to allow for precise control and restriction of flow, ensuring the buffer vessel is able to maintain the 60°c required. Following this, heat pumps two and three were assigned to provide DHW to the DHW plant room and to support the heating system. Once heat pumps two and three achieved their assignment of supporting the DHW system, the pumps were set to support the heating system.
This facility had been struggling to provide basic care needs prior to this project but as a result of diagnosis and these engineering upgrades and fixes, the system has been restored to normal efficiencies and provides all the required heat and hot water.
