The purpose of the service hot water recovery calculator is to provide a tool for a refrigeration designer to use in estimating the potential energy savings of capturing heat from a refrigeration system for use in pre-heating a domestic hot water system. This tool assumes that only the superheated vapor portion of the refrigeration system's total heat of rejection will be captured with a heat recovery tank. Tank-type heat reclaim systems are one of the most common methods of heat recovery due to both their cost effectiveness and that large volumes of hot water are often consumed in supermarkets on a daily basis. This spreadsheet is intended for use by refrigeration or mechanical designers for rapid yet robust calculation of energy performance. This calculator assumes that the refrigeration input of the hot water recovery tank operates in series between the refrigeration compressor rack and condenser to capture superheat from compressors prior to condensing. This calculator also assumes that the domestic cold water supply is the only input to the hot water recovery tank and that hot water recirculation is not present or is returned to the service hot water system after the hot water recovery tank.
This spreadsheet is designed for use with the Refrigeration Playbook: Heat Reclaim report (www.nrel.gov/docs/fy15osti/63786.pdf). Please note that this calculator is not currently approved for use on Mac computers.