Everything Old Is New Again From tenements to towers, tankless water heaters are bringing the green concept full circle. N By: Robert Kravitz Robert Kravitz is a writer for the professional cleaning, building, hotel, hospitality and education industries. He may be reached at Robert@ AlturaSolutions.com New York City is home to one of the most unusual museums in the world, the Tenement Museum in lower Manhattan. This museum preserves some of the apartment buildings, known as tenements, where people from all over the world began their new lives in America more than 100 years ago. Conditions in these tenements were meager, to say the least. Located in the kitchen and bathroom of each apartment was a rectangular box hanging on the wall. Along with paying for water and electricity, tenants would place a quarter in one of these boxes and, for about two hours, the box gener-ated hot water for washing, bathing and other personal needs. These boxes were the original tankless water heaters. And, while we may no longer have to put a quarter in them, tankless water heaters have been making a big comeback in the past few years because they can help significantly reduce energy consumption. virtually throughout the day, whether hot water is requested or not. Similar studies of hot water demand periods have been conducted in restaurants, office build-ings, schools and even sports arenas. In restaurants, hot water is typically requested about nine hours per day; although there can be variables, in schools and office buildings, the demand will fluctuate but is also likely to be around nine hours per day. A sports arena may only be used two or three times per week for three or four hours at a time, yet hot water is being produced essentially 24/7, whether it is needed or not. One does not require a calculator or computer spreadsheet to see the potential energy and cost savings that are possible if a hot water system is Hot Water Demand Periods Until recently, most people did not realize just how energy inefficient a typical hot water heater is. Studies indicate that in two-income homes and apartments without children, the hot water demand period — when hot water is most often requested by building users — is about two hours in the morning and about three in the evening, a total of five hours per 24-hour period. Yet, most conventional water heaters are designed to maintain what is called standby hot water 19 hours per day. The tankless heater requires energy only during the hot water demand period, whereas the con-ventional “tank” hot water system requires energy for more info Visit www.cmmonline.com and type in search keyword: Sustainability . For more information on related products, visit www.cmmonline.com , select SUPPLIER SEARCH from the main navigation bar, and enter keyword: Tankless Water Heater . Because of their smaller footprint, tankless water heaters can be installed virtually anywhere hot water is needed. 18 CM/Cleaning & Maintenance Management ® • October 2011
CMM – Archives Oct 2011: 18
