<VV> <VV>RE: heaters

Bill Hubbell Bill Hubbell" <whubbell@umich.edu
Sat, 10 Jul 2004 15:56:35 -0400


The thing is, you can have your cake and eat it too if you simply block off
the hole in the top shroud ("turkey roaster") and remove the hose to the
heater box (Early) or leave the hose disconnected from the top shroud
(Late).  Now, when you depress the AIR lever (Early) or push the HEAT lever
halfway (Late), you draw cool air from the top of the engine compartment but
don't steal it from the engine itself.  Of course, you need to run the
heater blower to get any airflow into the passenger compartment.  The
situation gets more complicated, though, when you depress the HEAT lever.
On an Early model, it is possible to have both the HEAT and AIR doors fully
open, and if you do that with the above setup and the heater blower not on,
you run the risk of recycling hot air from the bottom of the engine to the
top of the engine compartment, which is obviously not too good for engine
cooling.  Thus, you should never depress the AIR lever on an early with the
above setup unless the heater blower is turned on full blast.  On a late
model this is less of a problem, as the one lever controls both heat and air
doors, and generally it is not possible to have both fully open at the same
time, but you should still probably run the heater blower if you leave the
air intake open to the engine compartment.

Of course, keep in mind that under any conditions where the engine blower is
moving more air than the heater blower (faster engine speeds/slower blower
speeds) you may still get a recycling of hot air from the bottom to the top
of the engine, IF you leave the air intake open to the engine compartment.

Bill Hubbell



----- Original Message ----- 
From: <BobHelt@aol.com>
To: <hyarnell1@earthlink.net>; <virtualvairs@corvair.org>;
<wilk@cellbio.wustl.edu>
Sent: Saturday, July 10, 2004 3:41 PM
Subject: Re: <VV> <VV>RE: heaters


> In a message dated 7/10/04 12:08:10 PM Pacific Daylight Time,
> hyarnell1@earthlink.net writes:
>
> << And besides, why would you want to dilute the heated air with cool air
for
>  cabin heat? Dumb design. >>
>
> Harry, I beg to differ.
> It is not a dumb design at all. That is because the hot air coming off the
> engine can get very very hot: i.e., superhot. Hot enought to burn or at
least be
> extremely uncomfortable if you happen to have skin near an outlet. I can
> verify this personally! So Chevrolet add a mixing mode whereby some of the
cooler
> air from the top of the engine is added to the superheated air for a more
> comfortable feeling on the human body. Also maybe Chevrolet was trying to
avoid
> any potential lawsuits from heater burns.
> Regards,
> Bob Helt