AC not as cold as it used to be

1997 CRV 135500mi
Went on a trip yesterday...four pass and quite hot and humid out. The
AC in the car was cool, but not cold. Sometimes it would get colder
than others. On the way home that night the AC was plenty cold.
Never had this thing charged or anything...any ideas?

 

What was the outside temperature? A/C is only good for dropping the
temperature x degrees, not putt it down to a certain level. When it
hits 100 plus around here (last Thursday) my Fit had a lot of trouble
getting cool for quite a while.

Are you using recirc? That helps after a bit (but surely not at
first) since you are cooling air that is already cooler. But your
heat exchanger can only dump so much heat. That's why cars tended to
overheat back in "the good old days".

Driving during the day, hot air. Driving home at night, cooler and
less humid air.
--

- dillon I am not invalid

"You idiots, it's rape, pillage,THEN BURN!!!"
--- chief of the Aggie Vikings

 

Bigguy...

Dillon's likely spot on with his answer to your "problem."

If, however, you begin to see this occurring when it is NOT quite so hot
and muggy, it may be that your refrigerant charge is down a bit.
Actually, it's probably likely that your refrigerant charge on a 14 year
old car that's never had the AC service is marginal.

Easy to cure provided you read and follow directions. The little
recharge kits they sell at the auto supply stores work great PROVIDED
THAT YOU DO NOT OVERCHARGE the system. As stated - read and follow
directions, and in most cases you'll be back in Iceland quickly and
cheaply (>$25).

P.S. if you happen to overcharge the system, you'll know it as the high
pressure cutoff will kick in and the compressor will shut down. In
which case, simply bleed off (at the same port you're adding the
refrigerant) some of the charge and start over again FOLLOWING THE
DIRECTIONS THIS TIME<g>

 

"thebigguy" wrote in message

1997 CRV 135500mi
Went on a trip yesterday...four pass and quite hot and humid out. The
AC in the car was cool, but not cold. Sometimes it would get colder
than others. On the way home that night the AC was plenty cold.
Never had this thing charged or anything...any ideas?


This is likely not your problem, however. My air conditioner in my 98 CRV
just was not handling the hot weather like it once did. I complained to my
mechanic. He checked the coolant charge and said it was fine. He then asked
when was the last time my filter for the cooling and heating system was
changed. I told him never. He pulled it out and it was almost completely
blocked. This needs to be pretty clean for the Honda air to work very well.
Honda air conditioners have always been marginal. Everything needs to be in
very good working order for things to get cool.

Michael

 

OK...my mechanic said probably orifice valve (TXV). He changed it and
recharged the system and everything seems to be back to normal. $125
parts and labor. Dealership wanted $500. Also at lights, while
stopped I have the seemingly common problem of the AC "warming" a tad
and then when moving again it gets colder. What should the temp be
coming out of the vent?

 

Here's a great debugging tool. Get two instant read meat
thermometers. Put one on the front seat in the shade but in the open
air. Put the other in one of the output ducts. After about 5 minutes
the output should be about 8 to 12 degrees lower than the ambient. If
it's not, and if it doesn't keep this differential, you have a
mechanical problem. Last night it was 92 F at 8 pm. You can not and
will not get a car down to 70 F. But a good A/C (like Carol's Camrty
XLE) will get you around 80. Now, it was 100 plus when she got in the
car after forgetting to pop the sunroof and put up the sunshield and
it hadn't cooled enough to be "surviable" by the time she got home.

NB modern A/C units can do as much as 20 degrees differential. But
it depends on the outside temperature.

But not so "Unquestioable Confused" has also hit something real
important. And it could be multiple problems. His and mine working
against your best interests.

--

- dillon I am not invalid

"You idiots, it's rape, pillage,THEN BURN!!!"
--- chief of the Aggie Vikings

 

Yeah, I always have discomfort when my orifice is blocked.

See my other post. At least 8 F below the ambient inside the car
after about 5 minutes.

This is also the same methodology used to check your A/C at home.

--

- dillon I am not invalid

"You idiots, it's rape, pillage,THEN BURN!!!"
--- chief of the Aggie Vikings

 

Which is fine when the goal is air conditioning--because humidity
removal is the key. 80 degrees and dry is just fine for humans.

Not to be confused with refrigeration, which is way different. Humans
want conditioned air. Meat wants refrigeration.

Someone should have mentioned that to the Toyota engineers that made the
AC in my 94 Previa...not that I complained too much, after too many
years driving Hondas made in the 1980s....

 

Great description of the reality of air conditioning, Elmo.

 

although some may not feel like it, car a/c is in fact a refrigeration
device, not a dehumidifier - the condenser is /outside/ the passenger
cabin [and in a cooler location at the front of the car] to dump heat.
if the objective was simply dehumidification, it would be inside the
cabin and save complexity and money.

 

excellent point.

indeed. filters are a good thing though - they prevent the heat
exchanger getting clogged with dust, losing efficiency themselves and
breeding stink.

 

although some may not feel like it, car a/c is in fact a refrigeration
device, not a dehumidifier - the condenser is /outside/ the passenger
cabin [and in a cooler location at the front of the car] to dump heat.
if the objective was simply dehumidification, it would be inside the
cabin and save complexity and money.[/QUOTE]

'Tis true. It's a mix, a compromise--remove enough heat to the outside,
and you'll by definition remove enough humidity to be comfortable for
humans, which means you can stop removing heat sooner and therefore make
the system cheaper/smaller.

Unless you're Toyota designing the 94 Previa, in which case you presume
it's a vehicle being used by meatpacking houses for deliveries.