Possible a/c mod?

08EscapeHybrid · #11 07-09-2012, 08:22 AM

All you can really do about the glass is tint it to minimize solar gains.

herm · #12 07-09-2012, 08:23 AM

Quote:

Originally Posted by 08EscapeHybrid

I've never seen a compressor clutch wear out, and one of the vehicles I've had in the past I had set to cycle very quickly once it was on the edge of freezing the evaporator coil.

what breaks down in a car compressor?

I think some of the bigger cars use more than 2kW, probably a less efficient compressor.. and losses in the belts.

50 mpg by 2012 · #13 07-09-2012, 08:45 AM

Experiment.

We have a black steel BBQ grill about the size of a 20 gallon drum with a thermometer in the lid. Last week on a sunny afternoon with grill off for the previous 48 hours, the lid closed, and an ambient temperature of 100F (about 38C) ... the thermometer displayed 165F ... a full 65F (about 35C) rise in temperature ABOVE ambient with 5 of 6 surfaces shaded. And NO glass.

More than enough to run a thermosyphon hot water heater with an output temperature above what is considered safe in the US, 140F.

08EscapeHybrid · #14 07-09-2012, 11:56 AM

In my experience, I've only seen two types of failures associated with a/c compressors. The seals give out, and the compressor itself leaks freon, or the bearings on the clutch pulley go out. Replacing the pulley bearings is a simple DIY job, I did it years ago on my 74 Chevy C10. The bearing cost me $10, and the tool to pull the clutch off was like $15.

I also had just replaced the compressor in my nephew's 99 Cavalier Z24 last week, the main bearing seal was gone on the compressor, and it was leaking compressor oil and freon out the front. New compressor was $200, and a day of quality time spent under the car with my nephew: Priceless. Ice cold a/c: $300 after various parts and freon were purchased.

RedylC94 · #15 07-09-2012, 01:15 PM

As a local friend was on her way taking her '94(?) Civic to the dealer to trade in on a new one a couple of years ago, the compressor siezed, destroying the belt. If it gave any warning signs in advance, she didn't notice.

08EscapeHybrid · #16 07-09-2012, 02:12 PM

Most likely the bearing on the pulley gave out. There usually isn't any advance warning, it just seizes & burns up the belt. If she was going to keep the car I'd say its definitely a < $50 DIY job, including buying the tools.

Mendel Leisk · #17 07-09-2012, 02:27 PM

There was a device available, a few decades back, call "PassMaster". It was a vacuum activated switch. As long as it had decent vacuum the switch was closed. If vacuum dropped it opened. For vacuum you hooked it up to the engine's intake port. And the switch you wired into the power going to the AC compressor.

Whenever you encountered a steep hill, or needed strong acceleration, the compressor would cut out, temporarily, due to intake manifold dropping.

Here's something on it:

http://www.epa.gov/oms/consumer/devices/pb82178534.pdf

08EscapeHybrid · #18 07-09-2012, 03:54 PM

Yeah, being a hybrid, the car doesn't have any vacuum operated accessories to tap into for a vacuum reading. I remember my family's old K cars had a similar system though. Every time you went up a hill the a/c shut off. It used to annoy me to no end.

Mendel Leisk · #19 07-10-2012, 02:05 PM

Quote:

Originally Posted by 08EscapeHybrid

Yeah, being a hybrid, the car doesn't have any vacuum operated accessories to tap into for a vacuum reading...

Well, any car with a gas engine has an intake manifold with partial vacuum, and likely a spare vacuum port or two, in the manifold, regardless if it is an electrically assisted hybrid.

If you were running up a long hill the car interior tended to get kind of tropical by the time you neared the top, then cooled down again past the crest