Drake-- The kWh numbers are reasonable. A few years ago, I metered our hot water heater for a family of three and we were using an average of 10kWh/day--about one-third of our electric bill. A heat-pump water heater will reduce the kWhs, but they cost more and are louder. A better insulated water heater, insulated supply lines, low flow fixtures and better consumption awareness would also help reduce energy use.
regards, bill Bill Hennessy Berks Solar, LLC 371 Centennial Rd Mertztown, PA 19539 o 610 682 4300 c 484 560 4666 NABCEP certified installer PA contractor #44411 www.berkssolar.com From: "drake.chamber...@redwoodalliance.org" <drake.chamber...@redwoodalliance.org> To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Sent: Wednesday, March 14, 2018 7:19 PM Subject: [RE-wrenches] Electric Water kWh/ person Hello Wrenches, Is there a good way to estimate the power that will be consumed for electric water per person per day? We are estimating the amount of power that will be used by an all electric duplex, and the water heater amount seems high. The current model we have claims 3493 kWh/ year per 26 gallon tank will be consumed. With the two units, that would add up to 6986 kWh / year for hot water, pushing the system size to humongous for a 1300 ft sq building. Does that seem high? There will be a maximum of 2 people per unit. The owner is considering going to 115 V units with a 15 gallon tanks. I think the smaller tank would help, but it would seem that the amount of hot water consumed would be the main issue. How can we get a good estimate for a per person energy usage for electric hot water? Any other suggestions are welcome. Thank you, Drake _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
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