Milk Chillers and Today's Dairies.

 By Jaclyn Krymowski.

A long with the rest of dairy industry progress, milk chillers have undergone many advances and changes of their own. More than ever, dairy producers can select from a wide variety of types and sizes to best fit each unique dairy.

Unlike other pieces of farm equipment, chillers are seldom given much thought unless there is an issue. Though “no news is good news” when it comes to chillers, these silent workers are  as important as other equipment on the farm. Don’t neglect upgrades or take lightly the decision about choosing a chiller for your farm. And don’t neglect the chiller until it starts giving you serious issues.

An Overview on Chillers
One of the original, old school chillers used by small farms was simply a double-walled tank with water and cooling coils and  an accessory compressor.

According to Legacy Chillers blog, Milk Chillers in Dairy Farms, these chillers (still used on many smaller farms)  use the compressor to build ice on the coils and once the ice is a certain thickness the compressor shuts off and allows the ice to chill the milk.

But as farms grew and changed, so did the technology of chillers. Models  now use both air-cooling and water-cooling systems.

“Most plate chillers use glycol and water to cool milk,” the blog post author cites. “These chillers push milk through stainless steel plates to a glycol and water mixture on the other side, which cools milk to an appropriate temperature.”

The air-cooled types transfer the heat to the surrounding atmosphere versus the water-cooled to a water source. Both have advantages and disadvantages for space allotments or maintenance and maintenance costs.

In the 1960s, direct-expansion milk cooling tanks became the option of choice across North America, with capacities from 300-1,000 gallons. This development coincided with the industry’s move from cans to bulk milk pickup as the gold standard.

But this only lasted briefly as the herds continued to grow and needed a system with larger capacities. This also meant for increases in tank size or multiple tanks to manage increased capacity.

It wasn’t until  the 1980s that more of the modern “instant cooling” and in-line style chillers took the stage to accommodate larger farms and a faster milk flow.

On-Farm Options
In Bruce Derksen’s 2018 American Dairymen article Keeping Step with Dairy Chillers, Plate Exchangers and Coolers, he notes that as the overall number of producers decreases the aid of robots on operations has come to the aid to service the herd. This has also pushed those companies to take measures with their technology to connect to efficient chillers, plate exchangers and coolers.

Bringing the milk to the proper temperature through the use of both a cooler and refrigerant system is the most energy efficient way to proceed. But in the modern day an increasing number of dairies are facing the same issue. As their milk output increases with herd size, so does their need for an upgraded cooling system.
In many cases, this expansion may very well require  multiple chillers. To quote Derksen:

“Technology changes and advancements are inevitable, driven by the requirements of the dairy industry’s supply and demand. As dairy farms grow in size to meet these demands, the need for more adaptable, reliable, and cost effective energy efficient coolers, chillers and plate heat exchangers become paramount, offering today’s producers many viable choices to fit their ever changing operations.”

There are several considerations when selecting the right chiller for a dairy. In addition to size and milkhouse/parlor compatibility, there is also the question of energy. According to one statistic from New Zealand dairies, milk cooling can account for around 30% of farm energy costs.

Understanding the energy efficiency and expected costs should be on the list of questions to ask when replacing or upgrading chillers. Some varieties, like water cooled varieties, use less energy but have higher upfront costs and more intense maintenance needs compared to air cooled ones. On the other hand, air cooled chillers don’t waste water and are more simplistic in design. Lifespan expectancy and ease of maintenance are  equally important considerations.

Never Sacrifice Quality
Remember, the likelihood for bacterial growth in milk can begin at  45°F, and any inconsistency in temp checks within 3°F should give cause for concern and further investigation. You want a chiller that will be reliable and consistent to keep up with your dairy, especially if you are milking large groups, more than twice a day or have multiple milk houses. A faulty chiller can cost you at least one  milking. So, be proactive and don’t let that happen!

Your equipment in the milk house and parlor are just as important to the operation as making sure the cow is well looked after and milking well. Chillers play a vital role in maintaining the milk quality that you are pushing the herd to achieve  through all the other management practices that are being implemented. Make sure your chiller is not the weak link that impacts profitability.