5 Considerations When Planning Refrigeration Equipment for a Small Dairy
With consumer demand rising for niche dairy products like handmade cheeses and raw milk, it's a great time for starting up a small USDA licensed dairy. Yet many experienced livestock owners find their profits drained by the operating costs of the complex refrigeration units required for safely handling milk. Design and install commercial refrigeration units that don't cost an arm and a leg to run by planning out your systems correctly from the beginning.
Splurge on Scroll Compressors
Scroll compressors were once considered too expensive to be worth using in the dairy, but now they're common enough that the 20% potential energy savings makes them well worth the upfront expense. These compressors used a smooth scroll-shaped device to build air pressure rather than valves like reciprocating compressors do, and the scroll device lasts far longer than a valve because it's not constantly pushing against the building pressure. You'll enjoy both energy and repair savings for the lifetime of your refrigeration equipment by choosing the right kind of compressor up front, but scroll compressors can also be retrofitted onto existing refrigeration equipment later if necessary.
Prepare to Clean the Coils
As with air conditioning, dairy refrigeration units rely on metal coils to release the heat carried away from the milk by the refrigerant gasses trapped inside. These coils perform best when as clean as possible, yet many installations place these units in completely inaccessible locations. Designing the refrigeration system so the coils are accessible will keep your energy bills even because you'll actually be able to follow the recommendation of cleaning them quarterly. This is a job you or an employee can handle once you know how not to damage the coils, so you definitely shouldn't have them tucked away in an area that only a refrigeration technician should be accessing.
Pre-cooling is one of the oldest tricks in the dairy business for cutting down on refrigeration costs, but it remains as useful today as ever. As long as you have a steady supply of well water pumped up from the ground, you've got cooling power for nearly free. Pre-coolers run the milk over a cooling plate that has just plain water running through it rather than refrigerant. The water is cold from being underground, so it can drop the temperature of the milk by up to 30 degrees before it reaches the refrigeration cooling plate. Since it arrives at a lower temperature, it needs less time being circulated over the refrigerated plate and therefore costs less in total to cool.
Recapture Wasted Heat
Since milk drops roughly half of its heat in order to reach a safe storage temperature, you're generating a lot of free heat with every gallon you cool. Instead of just pumping that heat out into the world and losing it, try putting it to good use with a recovery system. Since everything that touches your milk supply needs regular sanitation with hot water, it's a natural fit to build a recovery tank in which the refrigeration system exhausts. If that doesn't tie up all of the waste heat your cooling produces, consider redirecting some of it directly to the livestock's living areas in the winter.
Stabilize the Flow
Finally, don't forget that the other parts of the milk processing system also affects the efficiency of your refrigeration system. The flow lines that move milk across the cooling plates are particularly important. If your pumps and lines are set up incorrectly or your volume changes without corresponding adjustments, the uneven flow will result in the refrigeration working harder than necessary. Invest in programmable logic controllers, multi-step pumps, and other flow control equipment so that your supply stays steady during cooling.
Contact a company like Ragan Mechanical Inc for help with other commercial refrigeration needs.