Evaluation of TANK Water Heater Simulation Model as Embedded in HWSim

This report evaluates the hot water temperatures and flow rates as calculated by the combined HWSim and TANK simulation models.

HWSim is a hot water piping simulation model originally written by DEG in the 1990s. DEG has updated the program using modern coding languages. For a specified hot water piping configuration HWSim will calculate the amount and timing of hot water to be drawn from a water heater to meet a schedule of given draws classified by type.

TANK is a computer simulation model of non-condensing center flue natural gas storage water heaters. Battelle developed TANK for GRI in the early 1990s. It was designed to simulate water heater operations only under test conditions. TANK was originally written in BASIC for DOS operating system in the early 1990s. For a specified water heater and a given amount and timing of draws, TANK will calculate the temperature of the delivered hot water. Energy consumption by the water heater is also calculated.

This work was sponsored by the Gas Technology Institute (GTI) which is funded by the California Energy Commission, Public Interest Energy Research (PIER) Program, under Residential Water Heating Program Contract No. 500-08-060. This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, State, and Community Programs, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.