Please settle an issue at our house. When the air/heat fan setting is off, I set the temperature to blue (cold)if it’s hot oustide, red (hot) if it’s cold outside. My husband says it doesn’t make any difference if the temperature is set to cold or hot, since the fan is off. (If it makes any difference, I drive a 2004 VW Jetta 1.8 Turbo five speed. Thanks!!
In most cars hot or cold air will still come through the vents if you are on the freeway even with the fan off. If not moving, no air will come through the vents and moving the selector to hot or cold makes no difference.
It does make a difference, whether the fan is on or off–at least on most cars.
Since some passive air flow through the vehicle’s cabin vents will take place at higher speeds–even without the fan being turned on–if the heater core has hot water flowing to it, then the “passive air flow” through the HVAC system will pick up heat from the heater core.
In the winter, this provides a very minimal flow of heated air to the cabin at higher speeds if the temperature control is set to “hot”. Similarly, in the summer this will introduce a minimal flow of heated air to the cabin, unless the temperature control is turned to the cold setting, thus shutting down the flow of hot water to the heater core.
Note that what I described above is not the case if you have an automatic temperature controlled HVAC system, as the entire system is shut off if there is no power going to the fan.
Can you percieve a difference? If you can feel a difference (in your head or by your hand) go ahead and do as you like.It doesn’t matter if I say no difference, it matters if you believe there is a difference, and since there is no harm either way,again do as you like.
It will vary from car to car, but I doubt if you or anyone would really notice the difference. Let’s no argue how many angles can dance on the head of that pin.
There is miniscule amount of air thats goes through the vents. But I’m going to say your husband is largely right Without the fan running it’s not going make a much of difference.
Trade your car in for one with climate control and save your marriage.
But I’m going to say your husband is largely right
In an argument between a husband and wife it seldom pays to have the husband right…lets just say the husband is larger.