Ōhakea Air Base makes historic move to cleaner reliable winter heating

New cleaner heating at Ōhakea will increase security of supply for personnel and visitors to the Air Force base during the cold winter months. Photo / Bevan Conley

Personnel at Royal New Zealand Air Force (RNZAF) Base Ōhakea are celebrating a significant change this winter as the old gas-fired boiler central heating system is retired.

For the first time, the Manawatū air base will rely on clean electric heating instead of the fossil fuel central heating system of a large boiler supplying hundreds of metres of steel water pipes around the base. It fed underfloor heating and radiator heaters throughout hangars, offices, the fire station and barracks.

The average winter low temperature at the base is 7C and a low of 4C was forecast this week.

After Base Ōhakea opened in 1939, it was heated by a coal-fired boiler which fed the heating pipes. The system was converted to natural gas in the 1980s.

Mark Brunton, New Zealand Defence Force (NZDF) head of defence estate and infrastructure,
said a feasibility study conducted in 2016 looked at replacing the boiler and included work funded by the Energy, Efficiency & Conservation Authority. Over the past few years, NZDF had steadily converted Ōhakea’s buildings to clean electric heating.

“Not turning on the central boiler is a very significant milestone for both Ōhakea and the NZDF,” Brunton said.

“Not only does this reduce the base’s reliance on gas, which generates more carbon emissions than electricity, it also provides more security of supply for heating.”

In 2020, the Government introduced the Carbon Neutral Government Programme (CNGP) which requires all government agencies, including the NZDF, to aim for carbon neutrality by 2025.

Brunton said transitioning away from fossil-fuelled boilers was a priority for all CNGP agencies.

“Moving faster to complete the decommissioning of the gas-fired central boiler at RNZAF Base Ōhakea was an early initiative in NZDF’s journey to a greener future.

“A report completed in May confirmed the project has resulted in the base achieving a 33 per cent reduction in natural gas consumption, offset by a 12 per cent increase in electricity consumption. The result shows an overall reduction in annual carbon emissions of 270 tonnes of CO2 equivalent.”

Brunton said carbon emissions reduction was not the only driver for the project and there had been additional benefits.

“The introduction of a centralised heat pump and ventilation system at the fire station has resulted in a positive air pressure condition, which aids in reducing the unpleasantness of aircraft fumes in the building.

“The previous piped hot water system meant that, in some circumstances, a failure such as a pipe leak could result in the entire network being out of commission for some time, affecting many buildings.”

The central heating boiler at RNZAF Base Ōhakea will not be turned on this year as the base converts to cleaner heating. Photo / NZDF

Brunton said decentralising space heating options around the base had eliminated the disadvantage so that now any system issues would only affect single buildings and not multiple facilities.

“Number 1 hangar, home to No 14 Squadron and the Central Flying School’s T-6 Texan II aircraft, has an underfloor heating system. Maintaining the required floor temperature was achieved by installing a 161kW air source hot water heat pump.

“At the large number 2 hangar, home to No. 42 Squadron’s King Air 350s, the project team considered several cost-effective options for heating a fairly large working area used by a small maintenance team.”

Ceiling-mounted electric infrared heaters were successfully trialled and installed.

“Radiant heaters heat objects and people, rather than the air, and work better in high-roofed areas, such as a hangar situation. It was also the occupants’ preferred option,” Brunton said.

The heating of barracks at Ōhakea had also been electrified.

A NZDF spokesman said the fate of the redundant boiler system was yet to be decided.