Although a Freeaire® All Climate™ system will generally save 30-50% of the cost to cool a walk-in cooler, freezer or refrigerated warehouse, the best answer to this question is “It depends.” A Freeaire® All Climate™ system includes a number of energy efficiency measures, each of which depends on a variety of factors that affect the amount of savings an owner will see.
It also depends on the cost of electricity. Commercial refrigeration is overwhelmingly dependent on the stuff, so most of the savings comes from lower electric utility bills. On those bills the cost of electrical energy, shown as cents per kilowatt-hour (kWh), is the most important factor. Energy savings occur whenever less energy is used less of the time. The cost for the utility having the necessary generating capacity available whenever it might be needed is called a demand charge, expressed as dollars per kilowatt ($/kW), is also important. Demand savings occur whenever more efficient equipment replaces less efficient equipment doing the same job, and sometimes when electrical loads like whole compressor systems can be kept off continuously for an entire month. A typical Freeaire system leads to a mix of both energy and demand charge saving.
Your savings will depend on the size of your electric and refrigeration loads and how often they now run unnecessarily. Do your reach-in door heaters run all the time? Or do you now switch them off manually during the winter? Do you even have heated doors? Do the evaporator units already have new efficient electronically commutated motors (ECMs)? Are some of the loads kept cold even when they don’t have to be? Could you take advantage of thermal coasting with outside air? Eliminating unneeded evaporator defrost operation offers great energy savings potential, especially with electric defrost. When they are running, oversized compressor systems consume more electricity than undersized ones, but need less time to get the cooling job done. This allows more potential energy-saving times the evaporators can be switched off.
Savings depend on any economies of scale involved as well. The payback period of an efficiency measure is its installed cost divided by the savings it generates annually on the electric bill. As a general rule, the larger the equipment being controlled the greater the energy savings and the faster the payback. A single Cooler ControllerTM can control dozens of 30” industrial-size evaporator fans drawing over a thousand watts apiece or a couple of small commercial ECM evaporator motors drawing only 40 watts each, and the installed cost will not be hugely different. It takes only a single sensor to measure the humidity by which to control one heated door or fifty.
Your savings may depend on climate and the weather. The difference between a space’s set point and the outside temperature is also a big determinant of the savings from using outside air. A 0°F freezer near the Arctic Circle can use a Freeaire® Polar Power® package to replace the condensing unit and evaporators for the three coldest months of winter there. A merely 40°F walk-in cooler in New England can use one during much of the fall and spring too. Even at the equator or in the middle of summer a Freeaire system can cool a server room up to 104°F more efficiently than an air conditioning system. We use historical temperature “bin data” from NOAA to closely determine the expected number of annual days per year that outside air can efficiently replace mechanical cooling by compressor system in your area.
You will also save money by avoiding spoiled product, needing fewer emergency service calls and reduced equipment replacement costs that stem from the lower runtimes and more reliable operation of a Freeaire system. The close monitoring of system operation provided by Web Interface Module (WIM) allows quicker action to correct problems, which offers savings from reduced product loss. Such savings are less predictable than energy savings, but are no less real.
The total energy and money saved by each of several efficiency measures being adopted at the same time won’t depend on the order in which they are considered, but it might affect how you feel about them. For instance, replacing old-fashioned shaded-pole evaporator fan motors with ECMs can reduce a constantly operating evaporator unit’s energy use by 70%. However, by switching the evaporator fans off when not needed after every compressor cycle and by using outside air, a Freeaire system can sometimes reduce evaporator runtime by 70%, also leading to a 70% savings. If an evaporator fan consumes $100/year in electricity before either of these measures is adopted, it would use $30/year after just one of them is installed, but only $9/year after the second. Each measure would save 70% individually, but together they would save 91%. It is misleading to say that one measure saves $70 and the other only $21. You need both to get the full $91 savings.
A free comprehensive energy audit is the best way to estimate with any precision the money that can be saved with a Freeaire® refrigeration system. Give us a call today.