Try the Takagi. I believe that all their units will modulate down to zero. Keep on eye on the temp rating of the unit...it is common practice to put the thermostatic mixing valve on the input side of the tankless.
Kris Legacy Solar 864 Clam Falls Trail Frederic, WI 54837 715-653-4295 [email protected] www.legacysolar.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Peter Parrish Sent: Tuesday, September 14, 2010 10:37 AM To: 'RE-wrenches' Subject: [RE-wrenches] On Demand Heaters for SDHW We have a SDHW client that wants to replace his old water heater with a new tankless water heater. We do a SDHW system about once a year, and only for clients that are getting a PV system from us to begin with. So this is not a big business line for us and we are behind the curve in terms of understanding the latest technologies. As I remember from an excellent workshop that I took about four years ago: when used in conjunction with a SDWH system, the tankless heater should (1) Modulate heat input based on INPUT water temperature (2) Be able to modulate down to ZERO BTU/hr The only unit I knew of back then was the Bosch 125BS (I believe). Today I can't find any bigger units that fit the above requirements. Short of using two Bosch 125BS units in parallel, does anyone have a solution? - Peter Peter T. Parrish, Ph.D., President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 CA Lic. 854779, NABCEP Cert. 031806-26 [email protected] Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
