Date: Mon, 25 Aug 2014 09:24:41 -0500
Reply-To: mcneely4@COX.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dave Mcneely <mcneely4@COX.NET>
Subject: Re: They said it couldn't be done....
In-Reply-To: <ipCX1o0143AraGZ01pCXJq>
Content-Type: text/plain; charset=utf-8
I was mistaken about the HEAT (not the AC) of the Prius. Despite having the car for years now, I still don't know everything about how it works. The cabin heat is conventional, with a heater core. It also has a resistance heater to provide some heat to the cabin almost instantly, because even with the heat conservation system in the engine coolant pathway (essentially a thermos bottle) coolant warm up is slower than resistance. I do know that within seconds of startup, I have heat for the cabin and the defroster. Because coolant temperature drops when the engine is not running, despite the thermos bottle, the engine may run more more in cold weather than in moderate weather, so mileage improves in spring, but falls again in winter.
mcneely
---- James <jk_eaton@hotmail.com> wrote:
> I don't know about the Prius, but I do know that Toyota has used a heat pump system, electrically driven, in vehicles, because the 1998 RAV4 electric I test drove (thanks to Georgia Power) had a heat pump system for cooling and heating - it was good down to about 30F/-2C, and below that had an electric heating element to assist it. One nifty feature was that you could program the heat pump to come on 20 minutes before you needed the car, so it could heated or cooled before you got in.
>
> Given their success with that system, I'm surprised that Toyota wouldn't use it on the Prius - the heating component saved on electricity compared to regular resistive element heating. But, it was more expensive to build.
>
> James
> Ottawa, ON
>
> > Date: Sun, 24 Aug 2014 13:07:44 -0500
> > From: mcneely4@COX.NET
> > Subject: Re: They said it couldn't be done....
> > To: vanagon@GERRY.VANAGON.COM
> >
> > ---- Jim Felder <jim.felder@gmail.com> wrote:
> > > I looked into the electrical AC in the Prius a while back, interesting. Is
> > > any manufacturer using them like a heat pump, to provide heat, too?
> > >
> > > Jim
> >
> > I have a Prius. The AC is driven by an electric motor rather than by the gasoline engine because the engine shuts off periodically, and in town driving, frequently. Of course, if the compressor were engine rather than motor driven, then it would shut off, too. The first Prius models in fact were like that. People didn't like it.
> >
> > I have not heard of any automotive AC system operated as a heat pump. Interesting thought, might improve efficiency, and thus mpg a tiny amount. mcneely
> >
> > >
> > >
> > > On Sun, Aug 24, 2014 at 9:50 AM, Dave Mcneely <mcneely4@cox.net> wrote:
> > >
> > > > Heat would have to be resistance, AC would have to be driven by separate
> > > > electric motor (latter would be like most hybrids and EVs on the road now,
> > > > factory built). Interesting that it indicates a manual transmission. Not
> > > > common in electrically driven vehicles. mcneely
> > > >
> > > > ---- Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:
> > > > > Add doesn’t say if it has heat or air conditioning.
> > > > >
> > > > > Dennis
> > > > >
> > > > >
> > > > > -----Original Message-----
> > > > > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> > > > Of Jim Felder
> > > > > Sent: Sunday, August 24, 2014 8:25 AM
> > > > > To: vanagon@GERRY.VANAGON.COM
> > > > > Subject: They said it couldn't be done....
> > > > >
> > > > > And maybe it couldn't, but here is an all-electric VW bus that the owner
> > > > claims will run on the highway, 200 mile range, etc.:
> > > > >
> > > > > http://bham.craigslist.org/cto/4627305079.html
> > > > >
> > > > > Jim
> > > >
> > > > --
> > > > David McNeely
> > > >
> >
> > --
> > David McNeely
>
--
David McNeely
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