Keeping the dairy industry moving

A small Waikato-based company shares their experience in providing HVAC&R solutions to the dairy industry, the challenges faced in this area today and what needs to change

No one needs to be told that dairy means big business in New Zealand. In the year to March 2023, the sector contributed over $11.3 billion to the country’s GDP.

Something that is often forgotten, though, is the essential role HVAC&R plays in the success of the industry: the quicker milk is cooled after milking, the better the quality when it is collected from the farm.

The Ministry for Primary Industries New Zealand Code of Practice for the design and operation of Farm Dairies has milk cooling standards that state that raw milk must:

a. be cooled to 10°C or below within four hours of the commencement of milking; and

b. be cooled to 6°C or below within the sooner of:

i. six hours from the commencement of milking, or

ii. two hours from the completion of milking; and

c. be held at or below 6°C without freezing until collection or the next milking; and

d. must not exceed 10°C during subsequent milkings.

However, with milk cooling accounting for about 30 per cent of the total energy costs of operating a dairy farm, paired with climate targets, farmers also need systems that are cost- and energy-efficient.

Based in Te Awamutu, King Cooling & Heat Pumps is focused on helping its local customers achieve this.

“With what’s going on in the industry and with climate targets, I had to look at other options of what would be best moving forward for our customers’ efficiency,” says Bradford Johanson, director at King Cooling & Heatpumps.

“We had to change the game from what was out there with refrigerant at the moment and the carbon tax charges that are attached to them. We found units being built in New Zealand using Temperzone units from Ice Cycle LTD, a small company in Napier using R32 refrigerant, with inverter compressors on them instead of fixed speed, which means greater efficiencies again.”

While some companies are still offering R410A systems which are being phased out, says Bradford, the R32 systems are providing King Cooling & Heatpump customers with a viable, more efficient solution that will last beyond the phase-out of high global warming potential (GWP) refrigerants.

“With R32, it is a single compound refrigerant with a slightly higher GWP, but it requires only around one-third less charge for the same refrigerating effect as some of the refrigerants being offered moving forward. So, all factors need to be considered when looking for improvements. Also, no companies hold a patent over it, so this isn’t factored into the selling price, which is a bonus for the end user,” says Bradford.

“We thought it was our responsibility to offer this to our clients. Some companies are offsetting the carbon that they’re using instead of minimising the carbon that they’re using. Is this helping stop climate change? Planting forests is a good thing that should be done on a value system; it isn’t targeting the cause.

“There are two sides at work. We’ve got to look at the climate side of it and how that affects things. But we’ve also got to look at the efficiencies of the systems we put in because that affects the climate as well with the power usage going into them.”

Advice for the industry

Moving forward, Bradford says there also needs to be more focus on the maintenance of HVAC&R being used in the dairy industry across New Zealand, paired with the right training to provide customers with the right information.

“We need to be really proactive on refrigerant leaks and more rigid on maintenance to make sure there are no ongoing problems and that equipment is being upgraded when it needs. If technicians aren’t trained properly and haven’t got the skills or the knowledge, they can’t give the client good advice – not every farmer knows, they rely on us.

“As an industry, we have to say what direction is needed.”

Do you provide HVAC&R equipment or services to the dairy industry in New Zealand?

IRHACE would like to hear your thoughts on current challenges and any solutions available to improve these.

Get in touch eo@irhace.org.nz and editor@irhace.org.nz