Fresh air bypass - center dashboard vent


#1

Over the years I have owned two cars that had a “fresh air bypass” (or that’s what someone once told me it was called). This brilliant feature allowed the driver to flip a switch near the dashboard center vents and voi-la get fresh air through those vents that could be directed at your face. At the same time you could keep your feet toasty or defrost the windshield. The cars that had this were a Maxima and a Volvo (can’t remember their years - but 10+ years old now). Does anyone know of any current models that have this feature or know how I can find out short of researching every model for sale?

Any advice is appreciated…


#2

I just figured out that that’s what the cryptic “person with a blue head” switch does on my Honda. I think the fresh air vent used to be an “economy” feature, which let you stay cool-ish without using the air conditioning. Nowadays, AC systems are more efficient (and practially all cars come with them) so the manufacturer just figures you can use the AC or the vent fan.

Now, what I want them to bring back is kick-panel vents-- I am constantly amazed at how well they work to keep old cars that don’t even have a blower fan cool.


#3

Greasy, the trouble with the modern vehicle “vent” position is that air goes by the heater core anyway. Either the valve lets in a little hot coolant even though it is in the full cool position or the door that controls air flow is not fully sealed. What you get is warmer than ambient air. My car has a blend door, but I have been thinking about putting a vacuum-controlled valve on the heater core supply line. I could cut my duct temp by 5 degrees that way.


#4

“My car has a blend door, but I have been thinking about putting a vacuum-controlled valve on the heater core supply line. I could cut my duct temp by 5 degrees that way.”

Your engine needs constant coolant circulation at all times whether or not the engine is fully worm, or thermostat is closed. In some cars that is achieved by a by pass hose before the thermostat, and others by constantly having flow thru the heater core. Putting a cut off valve on a heater line that is not designed for one could cause big engine temperature swings, and or engine damage.