From: croy on
In a modern car (such as a Toyota), when the "recirculate"
feature of the cabin air system is activated, how much fresh
air is getting into the cabin? Surely, it couldn't be zero,
as this would asfixiate the driver (that is if he/she didn't
get drowsy and crash before then).

I would think that recirculating the cabin air would be a
very wrong thing to do if the driver is getting drowsy.

On my RAV4, the recirculate feature seems to come on
automatically whenever the engine is started, or if any
other cabin air control button is pushed, or if I look away
from the controls for too long <g>.

Is the US DOT involved with design standards for the minimum
number of air-changes per hour, or anything like that?

Thoughts?

--
croy
From: Ray O on

"croy" <hate(a)spam.invalid.net> wrote in message
news:8n44569l9v50dfplppdpc8nl5bvd7p6tgr(a)4ax.com...
> In a modern car (such as a Toyota), when the "recirculate"
> feature of the cabin air system is activated, how much fresh
> air is getting into the cabin? Surely, it couldn't be zero,
> as this would asfixiate the driver (that is if he/she didn't
> get drowsy and crash before then).
>
> I would think that recirculating the cabin air would be a
> very wrong thing to do if the driver is getting drowsy.
>
> On my RAV4, the recirculate feature seems to come on
> automatically whenever the engine is started, or if any
> other cabin air control button is pushed, or if I look away
> from the controls for too long <g>.
>
> Is the US DOT involved with design standards for the minimum
> number of air-changes per hour, or anything like that?
>
> Thoughts?
>
> --
> croy

I have never seen published figures on how much fresh air enters the cabin
when the HVAC system is in recirculate mode, but it is definitely not zero.

Some Toyota HVAC systems automatically switch to recirc mode when max AC is
called for, then switch back to fresh. The system in my Lexus also switches
to recirc if a sensor in the system detects fumes like when you are
following a vehicle with a diesel engine.
--

Ray O
(correct punctuation to reply)


From: Clive on
In message <8n44569l9v50dfplppdpc8nl5bvd7p6tgr(a)4ax.com>, croy
<hate(a)spam.invalid.net> writes
>On my RAV4, the recirculate feature seems to come on
>automatically whenever the engine is started, or if any
>other cabin air control button is pushed, or if I look away
>from the controls for too long <g>.
On my Auris, if the minimum temperature is selected the recirculate
comes on, it is confirmed as being correct in the handbook. Just press
the appropriate button to turn it off.
--
Clive