Residential single family building practice currently ignores the losses of energy and water caused by the poor design of hot water systems. These losses include; the waste of water while waiting for hot water to get to the point of use; the wasted heat as water cools down in the distribution system after a draw; and the energy needed to reheat water that was already heated once before. Average losses of water are estimated to be 6.35 gallons (24.0 L) per day. (This is water that is rundown the drain without being used while waiting for hot water.) The amount of wasted hot water has been calculated to be 10.9 gallons (41.3L) per day. (This is water that was heated, but either is not used or issued after it has cooled off.) A check on the reasonableness of this estimate is made by showing that total residential hot water use averages about 52.6 gallons (199 L) per day. This indicates about 20 percent of average daily hot water is wasted.

The purpose of the Source of Alkali testing was to prepare feed for melt rate testing in order to determine the maximum melt-rate for a series of batches where the alkali was increased from 0% Na{sub 2}O in the frit (low washed sludge) to 16% Na{sub 2}O in the frit (highly washed sludge). This document summarizes the feed preparation for the Source of Alkali melt rate testing. The Source of Alkali melt rate results will be issued in a separate report. Five batches of Sludge Receipt and Adjustment Tank (SRAT) product and four batches of Slurry Mix Evaporator (SME) product were produced to support Source of Alkali (SOA) melt rate testing. Sludge Batch 3 (SB3) simulant and frit 418 were used as targets for the 8% Na{sub 2}O baseline run. For the other four cases (0% Na{sub 2}O, 4% Na{sub 2}O, 12% Na{sub 2}O, and 16% Na{sub 2}O in frit), special sludge and frit preparations were necessary. The sludge preparations mimicked washing of the SB3 baseline composition, while frit adjustments consisted of increasing or decreasing Na and then re-normalizing the remaining frit components. For all batches, the target glass compositions were identical. The five SRAT products were prepared for testing …