Energy use and domestic hot water consumption - Phase 1. Final report

New York State Energy Research & Development Authority has sponsored a project to develop comprehensive operating data on combined domestic hot water (DHW) and heating systems to be used in system design and specifications. The new, more precise DHW flow data (broken down on a per capita basis) result in a better foundation for sizing decisions. Thirty New York City multifamily buildings with combined steam heating and DHW plants were instrumented to monitor apartment, outdoor, boiler and DHW temperatures, and burner on-off times. In nine buildings, which had been upgraded, additional data collected were: stack temperature, DHW flow in 15-minute increments, oil and boiler make-up water flows, and DHW temperature before and after the mixing valve and on the return line. The data set collected for 14 months amounts to a data base of over 110 megabytes. This report presents DHW demand patterns, seasonal variations, weekday vs. weekend consumption, consumption vs. occupancy levels, coincidence of 15-, 60-, 120-, and 180- minute demand periods, and average vs. peak demand levels, as well as figures for energy to generate DHW. The format of guidelines presented in this report differs from those currently in use. The {open_quotes}Low - Medium - High{close_quotes} (LMH) usersmore » set of guidelines provide a range, rather than a specific, singular gallonage standard. By providing LMH tables and guidelines for their application the design engineer or contractor can then use these as a tool from which to select the appropriate level that matches the site being served. Values are presented for both New York sizing guidelines (developed from this study), as well as a set of {open_quote}National{close_quote} figures (derived from a compilation of studies conducted in other cities). The LMH approach and {open_quote}National{close_quote} guidelines were adopted for inclusion in the 1995 ASHRAE Handbook revision.« less