Innovation Exchange challenge: sustainable approaches to heating and thermal storage and utilisation within hospitals

Hull University Teaching Hospitals (HUTH) aim to decarbonise the estate and infrastructure by 50% by 2028 and have asked Innovate UK KTN to work with them to help them identify potential innovative solutions to be able to deliver and deploy solutions to help them meet their targets. In the future of the estates, the Trust is working to reduce the energy demand of its buildings while considering power generation and efficient use of energy. Their desire is to make the hospitals as independent as possible in the future to have a robust health service that is secure and safe.

Currently, across the sites within HUTH, heating is achieved by gas boilers to raise steam and hot water together with air source heat pumps. The buildings across the sites have different sorts of heating in them, some of which were installed as part of the original build program.

For this challenge HUTH seeks innovative alternatives to heating hospitals that offer good payback and net zero carbon and can be easily installed or retrofitted into existing buildings. 

There are a variety of buildings, installed systems and considerations across the trust:

• Five large multi floor buildings, fed via a steam network from gas fired boiler houses, with two boiler houses each containing 4 directly fired triple pass package steam boilers and 1 single pass waste heat boiler taking heat from the site CHP
• A total of 12 steam boilers
• The waste heat boilers are rated at 1T/hr each
• The 4 boilers at CHH are rated at 6.5T/hr each
• There are 2 boilers at the sterile services unit 5 T/hr and 4.5T/hr
• The HRI boilers are rated at 2 at 8T/hr and 2 at 5T/hr; these 4 are fitted with economisers
• CHH site has one steam network, where steam production is supplied from a single gas supply located at the energy centre. A second supply is used to run the CHP for electricity and steam from a waste heat boiler, a third gas supply feeds the centre of the site to produce hot water and heating by small standalone gas boilers, and the fourth gas supply is used to feed the east of the site, again with small standalone boilers for hot water and heating.
• The residences along Castle road have individual domestic supplies for gas separate to the site.
• CHH site has some small heating and chilling circuits that interlink, where heat pumps are backed up with gas boilers.
• HRI site has one steam network feeding a number of buildings; the boiler and CHP located in the Boiler house have a shared gas supply.
• The remainder of HRI not fed by steam receives gas from three small gas supplies located in the Fountain street, the MRI building and the Brocklehurst building.
• There are a number of smaller chilled water circuits on the HRI site located in the Tower block.
• One large single storey building, surgical block CHH, is a building that operates on the ground floor with 1st floor plant rooms containing 30+ year old AHUs that run as a total loss system. The heating has 2 steam calorifiers producing 75 degree hot water to a low loss header. The CT and VT heating circuits are supplied from this header and are controlled by BMS.
• In smaller buildings, there are presently air source heat pumps  fitted across both sites, 8 at CHH and 5 at HRI giving a potential for innovative ideas in the remaining sites.
• Locations of preferred storage units: HRI possible locations include the Boiler House, tunnels, containers could be accommodated in various locations.
• CHH has more flexibility to accommodate storage.

Much of HRI and the Cardio and Oncology buildings at CHH are larger buildings supplied by a steam network for both heating and hot water. The cost of removing these systems and replacing with any new technology would need to be considered over the pay-back of a new system. These systems run from boiler houses into the main site by underground piping which also means there is heat loss from building to building. It is very important that any new source can deliver water continuously at 65*C, any solution must comply with relevant legislation and Hospital Technical Memorandum.

The hospitals would look favourably on innovations that might generate the steam for the present system and would welcome ideas on net zero powering of this proposed heat generation system.

There are areas in the grounds around the hospitals that could be used for deep bore holes for heat pumps but it is noted that approaches suggested here must be aware of potential underground water piping and underground water channels on sites and appreciate that for some sites it may not be feasible for heat pumps if piping is already present.

The hospital is particularly interested in thermal storage and how it can be used to store excess energy from the existing solar PV to provide heating when required.

Alternative energy locations;
The hospital is also looking at using its grounds to extend its solar energy system to produce more energy that could be turned in to other sources of fuel like Hydrogen or used as a thermal store.

The areas the Trust would like to engage innovators are;

• Heating systems for the larger buildings which the preferred solution might include using the steam services in place. One location has an aquifer at 50 metres deep.
• Heating systems for smaller buildings, some brick, some porta-cabin style.
• Alternative, more sustainable fuels.
• Thermal storage and recovery systems
• Systems that could convert solar or other renewables into Hydrogen for use as a fuel source on site; it is useful to note that in any hydrogen conversion, the hospitals have a demand for oxygen as a medical gas administered to patients.
• Any other innovative ideas that offer sustainable heating options without impacting on day to day operations of the hospital, staff or patient care.

No and low costs solutions are requested. The Trust is keen to support new technologies and serve as a demonstrator site to enable proof of concept and evidence to be collected for future development and marketing purposes.

The Trust would be willing to consider solutions that have potential pay backs of sub two years.

To find out more, and to see technical details and functional requirements, visit the Innovation Exchange site at the link below.