The $9 million system, changed over on Monday, has set the hospital up for the future.
Health NZ Canterbury general manager, rural health services Berni Marra led a small group around the hospital grounds as the last coal boiler was turned off to make way for the new system.
Among those present was Ashburton Hospital and rural services site maintenance manager Dan Wilson, Health New Zealand facility and engineers manager Terry Walker, Ashburton and Rural Health Services operations and administration manager Philippa O'Neill and project manager Mike Frude.
The one year build saw the replacement of the hospital’s 40-plus-year-old boilers as part of a decarbonisation project.
It was among a $12 billion government programme, to build and upgrade roads, rail, schools and hospitals, announced in early 2020.
The project replaced three coal boilers with a ground source heat pump, which will provide heating and hot water to all the buildings on site.
It will reduce Health New Zealand’s carbon emissions by 2385 tonnes per year, the equivalent to the average annual emissions of 840 cars.
After days testing the new system in stages, Wilson silenced the last working boiler at the hospital with the flick of a switch. It was unlikely to have lasted another winter.
He estimated engineers would have been called out to fix the boilers thousands of times over the years. It was very outdated.
Facility and engineers manager Terry Walker said it was the mid-1960s when the two big boilers were commissioned.
They were fully attended by boiler operators 24/7 until 1985 when a smaller unattended boiler was added.
‘‘It could work through the evening. The attended ones took the big load through the day and the little one kept us going,’’ he said.
‘‘Even after 25 to 30 years its absolutely on its last legs and Dan has done brilliant job to keep it going the last six years.’’
The new system, manufactured by Airtech NZ Ltd, includes a ground source heat pump housed in a new building behind the laboratories. It works like a household heat pump that transfers heat energy from the outside air to the inside.
Real time visibility on the system can be viewed remotely via computer from anywhere.
‘‘It monitors 28,000 different parameters. These are cutting edge, there is nothing better than these in New Zealand, or more advanced,’’ Walker said.
Heat out of groundwater is sucked up from 100m and circulated around the hospital’s heating system.
The hot water replaces steam and will reduce the hospital’s energy costs by an estimated 30 per cent.
The residual water is discharged back into the ground.
The project was one of 19 coal boiler replacements undertaken by Health NZ since 2020 and was the last Health NZ coal boiler to be replaced in Canterbury.
It was a significant milestone in the decarbonisation programme and funded by Health NZ, and the State Sector Decarbonisation Fund, which is administered by the Energy Efficiency and Conservation Authority.
