A proprietary electronic device intended for use in existing commercial reach-in and walk-in cooler and freezer refrigeration control systems to optimize defrost cycle initiation. Smart defrost controllers can save hundreds of dollars each year, depending on the size of the cooler or freezer unit, by reducing the frequency of energy-consuming defrost events.
Status:
Baseline Description: Conventional Defrost Timer or Control Baseline Energy Use: 3559 kWh per year per unit
Baseline is a 0F commercial walk-in cooler, 11'x11'x7'9" with 4" wall insulation. Defrost heaters are (2) 2,500 watts, and defrost occurs for 30 minutes three times daily. The size of the freezer and defrost is from a study performed for the Regional Technical Forum (http://rtf.nwcouncil.org/meetings/2008/09/BPA%20Walk%20In%20LT%20Gasket%20Test%20080920.pdf), which also estimates that the defrost occurs twice daily. According to a representative of Heatcraft Refrigeration Products, defrost heat results in an increase in refrigeration energy of approximately 30% of the defrost wattage and defrosting typically occurs four times daily for half an hour.
"Typical" Savings: 30% Energy Savings Reliability: 4 - Extensive Assessment
Energy Use of an Emerging Technology is based upon the following algorithm. Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
NREL, 11/04/2013. Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance: Grocery Stores Building Technologies Program
Brian Fricke, 10/05/2011. Demand Defrost Strategies In Supermarket Refrigeration Systems Oak Ridge National Laboratory
Technical Advisory Group: 2009 HVAC TAG (#2) TAG Ranking: Average TAG Rating: TAG Ranking Date: TAG Rating Commentary: