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Old 10-15-2008, 10:31 PM   #8 (permalink)
Xringer
Old Retired R&D Dude
 
Join Date: May 2008
Location: Woburn Mass USA
Posts: 702

Little Red - '12 Toyota Prius c 2 Two
90 day: 57.82 mpg (US)

"Whitey" Bulger - '14 Toyota RAV4 LE
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Quote:
Originally Posted by NiHaoMike View Post
Just beware that you'll have to recover the refrigerant before you cut any pipes. You'll need an EPA certification to do that. Unless, of course, the cause of failure was a broken pipe, in which case there will be no refrigerant left to recover.

The A/C compressor doesn't use that much power anyways. One datasheet (Danfoss BD250GH) referenced 230W at maximum capacity.

You can use a DC/DC converter to power the existing compressor from the high voltage batteries. If the high voltage is in the range of 150-350v, a PC power supply with active PFC can be modified into a DC/DC converter. The inrush surge might be a problem, but some multi-farad capacitors of the kind used in car A/V systems should fix that. If you need to replace the compressor anyways (which would require an EPA certification), you can check local HVAC supply shops for line voltage compressors (which can run from high voltage DC with a relatively simple MOSFET inverter), but some HVAC supply shops only sell to businesses.

There's also the option of silicon heat pumps, but they operate from low voltage DC, so back to that problem again. System design is also a little tricky.
I don't ever recall seeing a failed AC in a car that still had much refrigerant left in it..


Anyways, my post isn't asking how to better run or repair a car AC..
It's about the desirability of dumping your AC for better MPG..

Pretend it was a regular dealer option at a used car lot.
They both cost about the same..

Pick one:

A. 10,000 BTU AC system installed w/25 MPG unlimited miles.
(Until you turn on the AC, then it's 23.5 MPG).

B. Plug-In Mild-Hybrid system installed w/30 to 38 MPG for trips less than 20 miles.
(After 20 miles, it's back to 25 MPG).
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Cheers,
Rich

Current ride: 2014 RAV4 LE AWD (24 MPG)

Wife's Pizza Transporter
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