Re: '05 Vibe/Matrix A/C

On Tue, 07 Jun 2005 18:28:20 -0400, P K wrote:
[color=blue]
> Hi,
> I just used the A/C on my new base '05 Vibe (MT) yesterday and was a
> little disappointed. Although it was cool, it was not as cold as I
> expected it to be in a new car. Is this expected for the new
> refrigerant, or is is a characteristic of Toyotas, or is it a problem?
> THanks
> --PK[/color]


Back in the late 80's/early 90's, they made the switch from R-12 Freon to
R-134a refrigerant. The R-134 was terrible. It took a few years but they
found by increasing the size of the compressor they could compensate for
the lack of 'cool' from the R-12 used previously. BUT it STILL wasn't as
cold as R-12. I have found with my newer cars, the longer the compressor
is running (longer trips) the colder the AC gets. A 20 minute ride never
reached the cold levels an hour ride would. It seems in both my cars,
35-40 mins was required to reach maximum cool.

You can also increase the effectiveness by using RECIRC (although this can
fog the windows up) or by adding tint to the windows. Check local laws; I
had a green car with green tint, perfectly see-through, and I had to
remove it to pass the state inspection.

Hachiroku wrote:[color=blue]
> You can also increase the effectiveness by using RECIRC (although
> this can fog the windows up) or by adding tint to the windows.[/color]

Sorry, this doesn't make sense. Running on Recirculate means that you
are circulating the same (dehumidified) air through the A/C system
instead of bringing higher humidity air in as you would with the system
set to 'Outside'. The only reason that windows would fog up in
Recirculate mode would be if the drain line for the evaporator was
plugged.

"Travis Jordan" <no.one@no.net> wrote in message
news:v8rpe.96467$Wv.22452@fe08.news.easynews.com...[color=blue]
> Hachiroku wrote:[color=green]
>> You can also increase the effectiveness by using RECIRC (although
>> this can fog the windows up) or by adding tint to the windows.[/color]
>
> Sorry, this doesn't make sense. Running on Recirculate means that you
> are circulating the same (dehumidified) air through the A/C system
> instead of bringing higher humidity air in as you would with the system
> set to 'Outside'. The only reason that windows would fog up in
> Recirculate mode would be if the drain line for the evaporator was
> plugged.
>[/color]

Nevertheless, that's what happens. I'd guess recirc mode also prevents the
air from leaving the cabin. That plus people exhaling puts more moisture in
the cabin than is in the outside air. Also, in defog mode if that's used to
keep the windows from fogging up, the windshield gets so cold condensation
forms on the outside.

Pat

hachiroku wrote:[color=blue]
> Also, if you notice, there is a point to which the AC clears the
> glass...after that condensation starts on the OUTside of the window.[/color]

That is true. However, here in Florida the in car humidity is always
lower with the A/C on and in recirculate, even if the car is full of
people. Something about the swamp....

"Travis Jordan" <no.one@no.net> wrote:
snip[color=blue]
>That is true. However, here in Florida the in car humidity is always
>lower with the A/C on and in recirculate, even if the car is full of
>people. Something about the swamp....
>[/color]

It shouldn't be...what takes the moisture out of the air is when
the moist warm air blows over the cold surfaces of the heat
exchanger the moisture condenses on the cold fins and runs off
overboard. When the air becomes cold (and picks up moisture from
the people) then there's not much difference in temperature
between it and the cold surfaces of the fins and little moisture
will be condensed on them. So you end up with cold moist air.

Don't you?...T'would seem so to me anyway...

--


-Gord.

"I'm trying to get as old as I can,
and it must be working 'cause I'm
the oldest now that I've ever been"

"Gord Beaman" <gord@islandtelecom.com> wrote in message
news:dgupa15ratf2supi9ij5d26ai6fs9k5u82@4ax.com...[color=blue]
> "Travis Jordan" <no.one@no.net> wrote:
> snip[color=green]
>>That is true. However, here in Florida the in car humidity is always
>>lower with the A/C on and in recirculate, even if the car is full of
>>people. Something about the swamp....
>>[/color]
>
> It shouldn't be...what takes the moisture out of the air is when
> the moist warm air blows over the cold surfaces of the heat
> exchanger the moisture condenses on the cold fins and runs off
> overboard. When the air becomes cold (and picks up moisture from
> the people) then there's not much difference in temperature
> between it and the cold surfaces of the fins and little moisture
> will be condensed on them. So you end up with cold moist air.
>
> Don't you?...T'would seem so to me anyway...
>
> --[/color]

Gord,

What you're saying is true unless the outside humidity is really high, like
over 80%. Then, the humidity outside the car could be greater than the
humidity inside the car. Hot days with 80+% humidity are not uncommon in
the southeast and Asia.

The problem with continually running the AC in recirc mode is that the
interior air gets stale and the evaporator compartment gets musty so except
for the initial cool-down period, it is better to run the car in fresh mode.
--
Ray O
correct the return address punctuation to reply

You don't know any more about AC then you do about politics, it
appears.

It is far more efficient to further dehumidify the dehumidified
interior air than to try to dehumidify humid outside air. Do some
research before you post on a subject of which you obviously have
little of no knowledge, WBMA. LOL


mike hunt



Gourd Seaman wrote:[color=blue]
>
> "Travis Jordan" <no.one@no.net> wrote:
> snip[color=green]
> >That is true. However, here in Florida the in car humidity is always
> >lower with the A/C on and in recirculate, even if the car is full of
> >people. Something about the swamp....
> >[/color]
>
> It shouldn't be...what takes the moisture out of the air is when
> the moist warm air blows over the cold surfaces of the heat
> exchanger the moisture condenses on the cold fins and runs off
> overboard. When the air becomes cold (and picks up moisture from
> the people) then there's not much difference in temperature
> between it and the cold surfaces of the fins and little moisture
> will be condensed on them. So you end up with cold moist air.
>
> Don't you?...T'would seem so to me anyway...
>
> --
>
> -Gord.
>
> "I'm trying to get as old as I can,
> and it must be working 'cause I'm
> the oldest now that I've ever been"[/color]

ALL A/C systems exchange the interior air, even when run on
recirc.

Drive any vehicle with automatic climate control, where one sets
a desired temperature. Observe how it operates. Once the coil is
cooled the blower comes to full on. It starts on outside air to
move the hot air from inside the vehicle via the built in rear
vents. When the interior reaches a predetermined temperature it
switches to inside air. As the temperature you selected is
reached the blower speed reduces so that the RATE of cooling is
increased as the slower moving air passes over the coil. It
will only switch to outside air if the outside air temperature
drops below your selected temperature. If the humidastat
determines the outside air is too humid it will switch back to
inside air as needed to maintain temperature and humidity. Recirc
is the most efficient mode of operation albeit it a bit noisier.
Automatic system have overrides for those that chose to operate
their system differently however. If one read their owners
manual it will describe a similar manual selection, for those
HVAC systems are manually operated.



mike hunt



Ray O wrote:[color=blue]
>
> "Gord Beaman" <gord@islandtelecom.com> wrote in message
> news:dgupa15ratf2supi9ij5d26ai6fs9k5u82@4ax.com...[color=green]
> > "Travis Jordan" <no.one@no.net> wrote:
> > snip[color=darkred]
> >>That is true. However, here in Florida the in car humidity is always
> >>lower with the A/C on and in recirculate, even if the car is full of
> >>people. Something about the swamp....
> >>[/color]
> >
> > It shouldn't be...what takes the moisture out of the air is when
> > the moist warm air blows over the cold surfaces of the heat
> > exchanger the moisture condenses on the cold fins and runs off
> > overboard. When the air becomes cold (and picks up moisture from
> > the people) then there's not much difference in temperature
> > between it and the cold surfaces of the fins and little moisture
> > will be condensed on them. So you end up with cold moist air.
> >
> > Don't you?...T'would seem so to me anyway...
> >
> > --[/color]
>
> Gord,
>
> What you're saying is true unless the outside humidity is really high, like
> over 80%. Then, the humidity outside the car could be greater than the
> humidity inside the car. Hot days with 80+% humidity are not uncommon in
> the southeast and Asia.
>
> The problem with continually running the AC in recirc mode is that the
> interior air gets stale and the evaporator compartment gets musty so except
> for the initial cool-down period, it is better to run the car in fresh mode.
> --
> Ray O
> correct the return address punctuation to reply[/color]

<RustyFendor@mailcity.com> wrote in message
news:42ADB0C3.4CE272FC@mailcity.com...[color=blue]
> ALL A/C systems exchange the interior air, even when run on
> recirc.[/color]

I don't think anyone was implying that any A/C system did not exchange
interior air
[color=blue]
> Drive any vehicle with automatic climate control, where one sets
> a desired temperature. Observe how it operates. Once the coil is
> cooled the blower comes to full on. It starts on outside air to
> move the hot air from inside the vehicle via the built in rear
> vents. When the interior reaches a predetermined temperature it
> switches to inside air. As the temperature you selected is
> reached the blower speed reduces so that the RATE of cooling is
> increased as the slower moving air passes over the coil. It
> will only switch to outside air if the outside air temperature
> drops below your selected temperature.[/color]

Our 97 Avalon, 00 LS 400, and 03 Sequoia all normally use outside air in
auto AC mode unless the inside is really hot after being parked, in which
case it runs on high fan speed/recirc for a few minutes and then switches to
outside air. The Lexus will also switch to recirc if the system is sucking
in fumes, like when you are following a diesel bus or truck.

If the humidastat[color=blue]
> determines the outside air is too humid it will switch back to
> inside air as needed to maintain temperature and humidity. Recirc
> is the most efficient mode of operation albeit it a bit noisier.
> Automatic system have overrides for those that chose to operate
> their system differently however. If one read their owners
> manual it will describe a similar manual selection, for those
> HVAC systems are manually operated.
>
>
>
> mike hunt
>[/color]

I have not read the owner's manual for a Vibe or Matrix, but Toyota usually
recommends using recirc for initial cool-down or extreme conditions,
otherwise, use outside air to keep the air fresher.
--
Ray O
correct the return address punctuation to reply