MARKET OPTIMIZED CONDENSING WATER HEATER

摘要

NAECA’s most recent increase in efficiency requires all water heaters to have a .59 minimum Energy Factor (efficiency plus standby losses) as of January 1, 2004. Condensing water heaters on the market today have Energy Factors above .80, however the increased cost associated with the manufacture and installation for these water heaters presently outweighs the cost saved from reducing energy consumption. It was estimated that with an Energy Factor of .78 and projected market penetration of 12% the national energy savings would be .035 Quad and the carbon emission reduction would be 0.6 MMTC/yr. This study will help determine if a condensing water heater, designed for low cost, will meet market, durability and performance expectations for future water heaters. The Department of Energy with co-funding from The Gas Technology Institute contracted with Arthur D. Little, Inc. (now TIAX, LLC) to develop a “Market Optimized Condensing Water Heater.” The first phase of this effort, described in this paper, studied the market needs, developed several heat exchanger types and built prototypes using the most costeffective design. The method used to develop a low cost design involved minimizing changes relative to standard residential water heaters by maintaining similar parts and manufacturing processes. In order to achieve the largest market penetration with the shortest payback period; the combination heat and hot water market was targeted. A prototype was built to demonstrate the performance of the design in a typical combination heat and hot water system installation.