Thanks for the help with that math. I've thought about adding insulation for both thermal efficiency and road noise reduction, and I'll be getting a windshield reflector thingie today.
I was at my shade-tree mechanic's yesterday, and he, too, was skeptical of using either electric system for A/C. But...I'm now wondering: are there heat pump systems rather than compressor units that might be more energy efficient? I mean, short of hanging an apartment A/C unit out the window.... Regardless, I think electrically-powered A/C may be lower on the priority list. The original impetus was to use it to cool the batteries...but I'm now leaning towards insulated battery boxes with Peltier coolers. I can probably use the car's steel frame for the hot side heat sink depending on where the boxes get mounted, and a computer CPU heatsink and fan assembly inside the box for circulation. -- and probably use multiple small coolers rather than a single large one. It'd still be nice to keep the vehicle interior below ambient when plugged in, especially this time of year...but that can be a luxury add-on down the road. b& On Aug 1, 2014, at 11:03 PM, Dennis Miles via EV <ev@lists.evdl.org> wrote: > On the other hand a friend in St Petersburg, FL. uses a 7,500 BTU ac in his > S-10 Pickup (About a 400 watt load) and runs it from a 1,000 Watt 110v. > inverter... Your 25000 to 30000 btu/hr are two to two and a half tons (Same > as HP or similar to Kw. ) and that is as much a a small house. I used a > 42,000 btu/hr a-cond to cool a 2,240 sq ft manufactured home in Florida, > and it ran 2/3 s of the time. And now I am using 7,500 btu to cool 900 sq > ft with better insulation... > > Dennis Lee Miles > > (*evprofes...@evprofessor.com <evprofes...@evprofessor.com>)* > > * Founder: **EV Tech. Institute Inc.* > > *Phone #* *(863) 944-9913 (12 noon to 12 midnight Eastern US Time)* > > *Educating yourself, does not mean you were **stupid; it means, you are > intelligent enough, **to know, that there is plenty left to learn!* > > * You Tube Video link: http://youtu.be/T-FVjMRVLss > <http://youtu.be/T-FVjMRVLss> * > > > On Sat, Aug 2, 2014 at 12:22 AM, EVDL Administrator via EV < > ev@lists.evdl.org> wrote: > >> On 1 Aug 2014 at 13:17, Ben Goren via EV wrote: >> >>> it probably also makes sense to get an air conditioner that runs [on] >>> the 12V system so it, too, can run when the car is plugged [in] ... >> >> I'm not so sure. I've read that a typical automotive aircon moves around >> 25000 to 30000 btu/hr. That can take a fair bit of power and energy. >> >> For example, I just found (online) a 24500 btu/hr LG room aircon that uses >> 12.7 amps at 230 volts (2.9kW assuming unity power factor). A comparably >> efficient unit running on 12.7 volts would require 230 amps. That's a >> pretty sizable long-term load for your 12v system. >> >> To look at it another way, you'd need twelve fully charged 90ah lithium >> cells to run that aircon for an hour. Even at 50% duty cycle, you'd still >> need eight 60ah cells. >> >> The energy usage isn't so much of a problem if you're just talking about >> cooling the car while it's parked and charging, though don't forget that >> any >> power the aircon uses isn't available for charging. However, you'd still >> have to have a pretty robust 12v system to power it. >> >> I think you'd be better off with an aircon powered by the main traction >> pack >> voltage. At least the current required would be more manageable. >> >> David Roden - Akron, Ohio, USA >> EVDL Administrator >> >> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >> EVDL Information: http://www.evdl.org/help/ >> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >> Note: mail sent to "evpost" and "etpost" addresses will not >> reach me. To send a private message, please obtain my >> email address from the webpage http://www.evdl.org/help/ . >> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >> >> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA ( >> http://groups.yahoo.com/group/NEDRA) >> >> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140802/fb6f68fc/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140802/d33eaa1b/attachment.pgp> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
