I had 3 customers that were my data source. unfortunately, I had trouble monitoring the thermal systems and they got tired of me coming over daily to see the runtimes ect one gave up on solar thermal when a leak occurred, The other two I stopped monitoring because of expenses in the monitoring of the solar thermal.
On Thu, Mar 15, 2018 at 12:35 PM, cwarfel <cwar...@entech-engineering.com> wrote: > That would be a good analysis to share. I can see how it could be possible > with lower module costs, but I haven't seen any studies on this comparison. > Chris > > On 3/15/2018 1:17 PM, Darryl Thayer wrote: > > When I did my study of solar water heating I found that PV water heating > gave more hot water at a lower cost than solar thermal. the Heatpump water > heater was the big winner. > > On Thu, Mar 15, 2018 at 12:00 PM, Drake <drake.chamberlin@ > redwoodalliance.org> wrote: > >> This discussion has been a great help. The house is built and the >> plumbing is in, but could be modified. Wood stoves are not a likely >> solution. I think we need a different water heating strategy. >> >> Thank you all! >> >> Drake >> >> >> >> At 09:21 AM 3/15/2018, you wrote: >> >> Content-Type: multipart/alternative; >> boundary="------------EE4E9806B711DEF636076840" >> Content-Language: en-US >> >> This is what I came up with: >> >> The calculation is Q = mcp delta T >> >> Water Temp out = 120 >> >> Water Temp in = ground source Temperature @ 50F? >> >> delta T = 70F >> >> m = mass flow rate. ASHRAE is the source for this. 20gals per person >> per day = 20 gallons x 8.34 lbs/gallon = 167lbs/day/person >> >> cp = 1 BTU/lb-degree F >> >> Q = 167 x 1 x 70 = 11,676 BTU/day/person >> >> Divide this by the efficiency of the water heating system (I'll assume = >> .86) =11,676/.86 = 13, 577 BTU/person/day >> >> convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 >> kWh/month >> >> I checked this against one month and it seems reasonable. >> >> Website assuming ~3.5 family size comes up with @ 400kWh per month. They >> approached it another way with assuming run times. >> >> https://www.google.com/search?safe=active&source=hp&ei=Z3KqW >> vXiNsGb5wKJ2Kf4DA&q=electric+water+heater+use+annual+ >> consumption&oq=electric+water+heater+use+annually&gs_l=psy- >> ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0. >> 451.2360.0j6j4j0j1.11.0....0...1c.1.64.psy-ab..18.16.1952.0. >> .0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI >> >> >> Chris >> >> >> >> >> On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote: >> >> Barton makes a good point with regards to the incoming ground water >> temperature and the amount of heat required to bring it up to shower temp. >>  My recollection is that ASHRAE states 20gal/person/day for the first 2 >> people, then 15gpd or 12gpd thereafter. However those rates vary wildly >> with consumers, from those that never bathe to the high schooler that needs >> 3 showers a day. In the northeast water heating can be up to 19% of the >> total household energy load for the year. Also, I would recommend the air >> source heat pump water heaters if you have significant humidity or an on >> demand unit. Water tanks are typically under insulated and can lose >> 2kWh/day in standby losses. >>  >> Mike Kocsmiersky >> Principal >> Spirit Solar Inc. >> (413) 734-1456 >>  >>  >>  >> *From:* Barton Churchill [mailto:bar...@solarips.com >> <bar...@solarips.com>] >> *Sent:* Wednesday, March 14, 2018 7:31 PM >> *To:* RE-wrenches >> *Subject:* Re: [RE-wrenches] Electric Water kWh/ person >>  >> You first need to know your ground temperature. Then figure a delta to >> 100 or so degrees. Most but not all showerheads flow 2.5gpm and showers are >> typically 10 minutes. You can then find a calculator online to calculate >> how many Btus are required to raise water temp for your delta per gallon. >> Convert to kWh, add some contingency and you should be good. >> >> On Wednesday, March 14, 2018, < drake.chamber...@redwoodalliance.org> >> wrote: >> 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 >> >> >> >> -- >> -- >> Barton Churchill >> 406.587.5295 <%28406%29%20587-5295>  >> 2430 North 7th Bozeman, MT 59715 >> www.solarips.com >> [image: Image removed by sender.] >>  >> >> >> >> _______________________________________________ >> 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 >> >> >> -- >> >>         Christopher Warfel, PE >>       ENTECH Engineering, Inc. >> PO Box 871, Block Island, RI 02807 >>               (401)466-8978 <%28401%29%20466-8978> >>  >> [image: EEI logo] <http://entech-engineering.com> >> >> >> _______________________________________________ >> 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 >> -wrenc...@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 >> >> >> _______________________________________________ >> 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 >> -wrenc...@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 >> >> >> > > > _______________________________________________ > 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 > > > -- > > Christopher Warfel, PE > ENTECH Engineering, Inc. > PO Box 871, Block Island, RI 02807 > (401)466-8978 <(401)%20466-8978> > > [image: EEI logo] <http://entech-engineering.com> > > _______________________________________________ > 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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