Milk cooling: the easiest emissions win hiding in plain sight on NZ dairy farms
Luke Walker, Cryvex Chief Operations Officer
With a third of NZ dairy farmers still running outdated refrigerants and leakage rates that would shock most, the country’s largest farm refrigeration company says the opportunity for quick, meaningful emissions gains has never been clearer.
Luke Walker has spent 18 years in refrigeration, working his way up from his trade through to General Manager of DTS Refrigeration, New Zealand’s largest farm refrigeration company. He’s not prone to hyperbole. So when he describes the current moment in dairy refrigeration as a genuine opportunity for farmers wanting to cut emissions, it’s worth listening.
Luke was invited to sit on a panel at ARBS 2026, Australia’s premier refrigeration and building services expo, titled “Innovation Meets Practicality: The Future of 1–60kW Refrigeration in Australia and NZ”. The discussion brought together contractors, consultants, and industry leaders to work through the practical reality of refrigerant phase-downs: what the options are, what works in the field, and how to navigate a rapidly shifting regulatory landscape. The panel covered the full spectrum of technology choices for the 1–60kW sector including CO₂, hydrocarbons, HFOs, and blends.
Back home, Luke is focused on a message he wants NZ dairy farmers to hear clearly: the milk room may be the most overlooked emissions opportunity on the farm.
Older dairy refrigeration systems lose around 15% of their refrigerant charge annually through leakage. Commercial systems can leak up to 35% per year. When that refrigerant is R404A, a gas with a global warming potential nearly 4,000 times that of CO₂, those losses represent a significant and largely invisible emissions burden.
“By our estimate, roughly a third of NZ farmers are still running R404A in their milk cooling,” Luke says. “When you put that alongside the leakage rates, you’re talking about a meaningful emissions problem sitting on farms right across the country and most farmers have no idea it’s there.”
“It’s on us to sort it out”
Luke is under no illusions about how the emissions conversation lands in rural communities.
“We know dairy farmers are sick of hearing about emissions, especially when it comes from townies. We all know the cows aren’t the real problem,” he says with a laugh. “But that’s exactly why the refrigeration industry needs to lead the way here. This is one area where we can make a real difference without anyone having to point the finger at farmers. It’s on us to sort it out.”
The good news, he says, is that milk cooling is one of the more straightforward problems to fix.
“This isn’t like trying to reduce methane from livestock. The technology exists right now. The solutions are proven. For farmers who want to show real emissions progress, milk cooling is genuinely low-hanging fruit.”
NZ ahead of the curve, but the clock is ticking
One of Luke’s observations from ARBS 2026 was just how far ahead New Zealand is compared to Australia on the refrigerant transition. DTS has long advocated for moving customers away from R404A and that work has paid off, but a significant portion of the sector still needs to make the shift.
“The phase-down is coming whether the industry is ready or not,” Luke says. “The question is whether you’re ahead of it or scrambling to catch up.”
New technology making the transition easier
Luke says the transition has never been more accessible. The reception of A2L refrigerant units in New Zealand has been strong, with Actrol’s range gaining real momentum among contractors and processors looking to move away from high-GWP refrigerants.
DTS is also actively exploring partnerships with new brands entering the New Zealand market. Luke says there are some compelling systems now available that use CO₂ as a natural refrigerant, incorporating ice bank technology alongside integrated hot water heat recovery, generating ice during off-peak hours and capturing waste heat from the refrigeration process to heat water.
“The energy efficiency story is compelling,” Luke says. “You’re cutting operating costs while moving to a refrigerant that has essentially zero climate impact. It’s not just better for the environment, it makes commercial sense. We’re keen to work with the right partners to bring these solutions to New Zealand dairy farmers at scale.”
DTS services customers across New Zealand’s major milk processors including Fonterra, Westland, and OFI, with a customer base of over 6,000 nationwide.
Rebranding for what’s next
The timing of Luke’s ARBS appearance coincides with a significant milestone for the business: DTS Refrigeration is set to rebrand as Cryvex, a move that reflects the company’s evolving scope and ambition.
“The refrigeration industry is changing fast, regulatory pressure, new technologies, smarter systems,” Luke says. “We want a brand that signals we’re leading that change, not following it.”
For dairy farmers wondering where to start on their emissions journey, Luke’s answer is simple: open the milk room door.