May 16, 2011
When you see the terms “free air” (or “Freeaire” in the case of this story) and it is connected with refrigeration, you have to wonder how that is possible (regardless of the spelling).
Now comes a company from Vermont that calls itself Freeaire Refrigeration. It has come up with a technology, according to the company, designed to reduce electrical consumption “by eliminating unnecessary operation of every part of a system” and, for colder climates, adding an element that allows the use of cold outside air.
Said the company, “The heart and brains of every Freeaire® refrigeration system is our patented electronic Cooler Controller™, a powerful computer that maximizes efficiency by operating each component of a conventional refrigeration system only as much as it needs to.”
Then it noted, “But in colder climates, when the weather turns cool, the Polar Package™ doesn’t have to rely on a compressor system to produce cold air. It simply moves super-filtered cold air from outside to inside, using just a fraction of the energy.”
HOW IT WORKSAccording to the company’s website, here is how the system works. The system “makes sure that you are not wasting energy, and money, by running reach-in door heaters, evaporator fans, and condensing units unnecessarily. The cooler controller only allows operation of the evaporator fans when the compressor is operating. Evaporator fans are a significant consumer of energy and a significant source of heat, which causes more need for cooling. When the evaporators are shut down, a highly energy-efficient circulating fan prevents air stratification. To prevent against damage to the cooling system due to freezing, the cooler controller initiates air defrost when required, or controls an electrical defrost system if installed in a freezer. This saves the user a significant amount of electrical consumption even in the summer, plus it reduces wear on components.”
The company said the idea is to have the compressor operate as usual during warm weather. But then during cold weather, the Polar Package “uses outside air to take over the job of refrigerating.
“Whenever the outside temperature is at least 4°F cooler than the temperature inside your walk-in and cooling is needed, the Cooler Controller tells the intake fans to introduce outside air into your cooler. The Freeaire filter, with a MERV rating of 8, catches particles as small as 3 microns.”
The main purpose for having an intake fan and exhaust fan is to balance the pressure in the cooled space. Without powered exhaust, the enclosure becomes overpressurized, the company said.
“An exhaust fan lets warmer air escape from the cooler. When the proper temperature has been reached, the Cooler Controller turns off both intake and exhaust fans. In Northern climates, outside air can take over the job of refrigeration for months at a time. A condensing unit and evaporator fans may not run at all on many days, saving electricity costs, utility demand charges, and wear and tear on your equipment.
“When your walk-in is being cooled by Polar Packages, it commonly uses less than 10 percent of the energy needed by the compressor system to do the same job, for 150 days or more, each year.”
According to the company, Polar Packages can be used in old or new walk-ins as small as 500 cubic feet, and in warehouses with hundreds of thousands of cubic feet, all using the same modular 10-inch intake and exhaust units. As the size of the space and the refrigeration load increases, their procedure is to add more pairs of intake and exhaust fan units to handle the larger load.
CASE HISTORY: BEERIn one case history provided by the company, Harpoon Brewery used the technology in its Boston, and Windsor, Vt., warehouses.
“Beer is a perishable product, and the longer we keep it cold, the longer it stays fresh,” said Steve Miller, general manager of Harpoon’s Windsor brewery. “Our cooling has to be reliable.”
Freeaire said Harpoon invested in the technology because of the potential payback and the fact that it could be installed and running quickly. Said Miller, “Our installation was a great experience. It didn’t disrupt our normal operations. It happened really quickly; they were able to get the pieces needed in short order and have it up and running in a very reasonable amount of time.”
Freeaire officials said the brewer particularly likes the automatic defrost cycle, made possible by the controller. “The system has added defrost to our evaporative units so we don’t have to turn it off and do it manually,” said Miller. “In the past, the cooler fans were set to run constantly. This system shuts them down, whether because it’s pulling in cold air from the outside, or because the temperature is being maintained at our set point.”
CASE HISTORY: C-STORESIn another sample, Champlain Farms is a chain of 38 convenience stores across New Hampshire and Vermont, all of which use the All Climate and Polar Package. One advantage, said Dave Simendinger, owner of Champlain Farms, is the door heater control option, which automatically shuts off door heaters whenever possible.
According to Freeaire, Champlain Farms has a total energy reduction of 47 percent and a payback period of less than two years per store, as well as reduced carbon emissions in states where such factors are highly favored. “We expect the Freeaire system to deliver benefits to Champlain Farms, and the communities it serves, far into the future,” said Simendinger.
CASE HISTORY: DAIRYThe technology was also used at refrigerated storage warehouses of Pete and Gerry’s Organic Eggs of Monroe, N.H., promoted as the largest supplier of “specialty eggs” in the Northeast. “With a commitment to conservation, sustainability, and organic foods, the Freeaire system was a natural choice for refrigeration,” the manufacturer claimed. “Freeaire’s environmental benefits were a huge plus, because those values go along with everything that we market,” said Organic Eggs CFO, Jesse LaFlamme, who runs the business with his father, Gerry.
The farm combines storage and shipping operations in one location, enabling daily shipments rather than long warehouse layovers. “If our coolers go down, our eggs can only stay above 45° for 15 minutes before they can’t be used for retail,” said Jesse LaFlamme. “We have lots of confidence in this system. It really takes care of itself.”
He added, “Utility incentives paid for half the project, so it was a no-brainer.” He said he appreciated the built-in defrost cycles.
“We’ve had some major problems with the air-handling units before. Those have been taken care of, as the built-in electricity reports clearly show. This system is definitely saving us energy and headaches.”
For more information. visit www.freeaire.com.
Publication date: 05/16/2011