NHS Highland: Biomass boiler troubleshooting

NHS Highland plant room door Bonar Bridge

re:heat worked alongside NHS Highlands’ estate management team to provide them with specialist consultancy services, helping with a number of issues associated with wood pellet boilers across their sites in the far north of Scotland.

Having taken some first tentative steps into the world of wood-fired boilers, NHS Highland contracted with re:heat to take 5 hospital boilers through the RHI accreditation process and assist with troubleshooting some operational issues.  Our data gathering and site inspections found that none of the 5 systems were ready for RHI applications, and the scope of our work was widened to preparing specification documents for the remedial works necessary to bring the installations up the standard required, then to oversee the implementation of the works on site.Dust covered electrical switches at Lawson Memorial Hospital, Golspie

Initially contracted to register the sites for the Renewable Heat Incentive, we quickly discovered that the installations, four of which used external containerised plant rooms, were not eligible.  This was for a variety of reasons, most of which related to the manner in which the pellet boilers had been integrated with the existing heating systems and because of the choice of heat meters used on the jobs.  Our investigations also uncovered a range of other safety and operational issues with the systems including:

  • Poor fuel store design leading to pellet degradation, dust build-up and low storage volumes;
  • At one site, inadequate seals between the store and plant room, leading to significant dust build-up in the plant room;
  • External boilers integrated into the wrong part of existing heating circuits;
  • A lack of control integration;

    Auger showing very poor pellet quality as a result of store design
    Wood pellet auger troubleshooting
  • The use of pellet boilers which were inappropriate to the high duties seen in hospitals.

Many of our detailed recommendations were taken forward resulting in installations which are now safe, more efficient and crucially, eligible for payments under the Renewable Heat Incentive.

NHS Highland are one of a considerable number of clients with failed or sub-standard installations that we have helped get back on track with our troubleshooting services.