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Nissan Leaf Electric Car - How do they handle the Air Conditioning load?

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Posted by Jim on August 10, 2010, 11:49 pm
 


I live on the Central Gulf Coast, and today we had 103.8
degrees and very high humidity.  Anyone have an idea just how
the Nissan Leaf will handle this huge load, especially with
headlights running at same time.

I went to their site and the Leaf is supposed to have full
climate control, headlights and all the other amenities.

I would guess the A/C alone would use maybe 5 to 8 HP when
cooling.

Any ideas?  I think the specified range is 100 miles, but
suspect the A/C would cut this down quite a bit.  






Posted by Bill on August 11, 2010, 1:29 am
 


"Jim"  wrote in message

The smallest A/C you can buy for a house is 500 watts or about 5000 BTU's...

google calculator says 1 watt = 0.00134102209 horsepower...

Then at the following link it says this... "The average factory installed
auto A/C unit is rated at 1-3/4 ton." And... "A/C units are rated by
Btu/hour ratings. A one ton unit is rated as 12000 Btu's"
Link...
http://reviews.ebay.com/Frequently-Asked-Auto-A-C-Questions-Part-2_W0QQugidZ10000000000932442



Posted by Josepi on August 11, 2010, 3:00 am
 

A slight arithmetic error there, Bill. 5000 BTU would be equiv to about 1464
Watts+

http://www.mhi-inc.com/Converter/watt_calculator.htm





The smallest A/C you can buy for a house is 500 watts or about 5000 BTU's...

google calculator says 1 watt = 0.00134102209 horsepower...

Then at the following link it says this... "The average factory installed
auto A/C unit is rated at 1-3/4 ton." And... "A/C units are rated by
Btu/hour ratings. A one ton unit is rated as 12000 Btu's"
Link...
http://reviews.ebay.com/Frequently-Asked-Auto-A-C-Questions-Part-2_W0QQugidZ10000000000932442




Posted by danny burstein on August 11, 2010, 4:39 am
 



You're running into definitional issues there, as the US uses
different ways of listing the coolling capacity than Europe does.

You're correct that pumping 1,464 watts into a room
for an hour is the same as placing 5,000 BTU into it,
but...

 ... but ... in the US, when we're talking about cooling BTUs,
we're talking about the actual heat transfer.

A typical window unit has an "energy efficiency ratio" (EER) of 10
or so, which means (by definition) that getting 5,000 BTUs
of cooling requires 500 watts. Yes, going the other way
in a European conversion, 500 watts -> 1,800 or so BTUs.

The roughly 3 times difference is the "coefficient of performance",
but no one in the US thinks like that.

Again, we simply look at the EER. If a car unit has that
same EER of 10, then a 10,000 BTU unit (someone earlier posted
that a typical car a/c is one and a half "tons", which
is Yet Another Unit, equal to 12,000 plus 6,000 BTU/hr - but
I expect the Leaf would be smaller).

Anyway, a 10,000 BTU unit would require one kw (1,000 watts)
of power going through. That's very roughly (since we're
talking an electrical system with 90 or so percent efficiency)
equal to about 1.5 horsepower. (by definition one HP = 750 watt-hrs,
so 1,000 watt-hrs = 1.3333 hp, add in a fudge factor).

One and a half HP is most assuredely a noticable, but not
a critical, percentage of the general car usage. And I'd
expect Nissan would use inverter (proportional) controls
on the a/c, so if you only needed 1/10th the cooling, that's
what you'd actually draw.
:wq



So if a car nit
--
_____________________________________________________
Knowledge may be power, but communications is the key
             dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

Posted by Michael B on August 12, 2010, 2:08 am
 

The battery warranty is 8 years or 100,000 miles.



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