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#1
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Setting AC to Medium position waste Gasoline?
Just wondering how the AC in Vehicles work.
When you set the Air conditioning to less the max, does The AC still work at maximum capacity while mixing the really cold air with some hot air? If so, I would say that there is cold air is being wasted. It would make more sense to me if AC would turn on and off every few minutes, when you have it set to medium cold. As far as I know the AC is either on or off. There is no such thing as partially on. In my house the AC is on max and when the desired temperature is reached, the AC turns off. Can someone clarify this to me? Thanks. |
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#2
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Actually you are closer to the truth than you may know. The AC in your car
doesn't work full time, only the fan does. The AC compressor under the hood has a clutch mechanism that engages and disengages the compressor whenever it's needed or not. The amount of power the fan uses by having it run constantly is negligable on the low and moderate speeds so it doesn't make economic sense to add in a switch to turn off the fan while the AC compressor is disengaged. In fact, I think the interior of your vehicle would heat up faster if the fan wasn't running anyway, so you might as well keep air moving over the coils which are still cool after the compressor shuts off. Putting the controls on Max or Hi doesn't effect the compressor, just the fan speed and recirculation vent. It's actually more efficient to run your AC on "Recirc" where it draws in the already cool air from inside the passenger cabin, and many vehicles these days have a dedicated recirc button that can be activated regardless of fan speed. Hope this helps. Cheers - Jonathan > wrote in message oups.com... > Just wondering how the AC in Vehicles work. > When you set the Air conditioning to less the max, does The AC still > work > at maximum capacity while mixing the really cold air with some hot air? > If > so, I would say that there is cold air is being wasted. It would > make > more sense to me if AC would turn on and off every few minutes, when > you > have it set to medium cold. > As far as I know the AC is either on or off. There is no such > thing > as partially on. In my house the AC is on max and when the desired > temperature is reached, the AC turns off. Can someone clarify > this to > me? Thanks. > |
#3
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> just the fan speed and recirculation vent. It's actually more efficient
> to run your AC on "Recirc" where it draws in the already cool air from > inside the passenger cabin, and many vehicles these days have a dedicated > recirc button that can be activated regardless of fan speed. On not so newer GMs, before GM decided to use a "recirc" button like the rest of the world, the "recirc" function is the "max" setting on the dial. Steve |
#4
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"Steve Mackie" > wrote in message news >> just the fan speed and recirculation vent. It's actually more efficient >> to run your AC on "Recirc" where it draws in the already cool air from >> inside the passenger cabin, and many vehicles these days have a dedicated >> recirc button that can be activated regardless of fan speed. > > On not so newer GMs, before GM decided to use a "recirc" button like the > rest of the world, the "recirc" function is the "max" setting on the dial. > > Steve > Even back in the 1960's the GM AC systems used the "Max" terminology for the "recirc." function. I hadn't realized they finally changed it to the term every one else uses. Interesting. |
#5
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Many home AC system have a feature that shuts down the blower, as
well as the compressor, when the desired temperature is reached. The HVAC systems in automobiles do not, generally, have that feature. That does not mean they do not shut down however. The blower in AUTOMATIC climate control system will cut back but, generally, does not shut down. The compressor on both manually and automatic operated systems in cars does shut down when the desired temperature is reached, then restarts as needed. Generally, in cars the MAX setting is NOT the temperature setting, it is simply used to operate the AC in the most efficient mode by re-cooling the dehumidified inside air, much as it does in a home AC system. If not set to the MAX setting the system, generally, is taking in outside air and cooling that air. When using outside air the compressor operate more frequently to maintain the same temperature setting because it must cool the warmer more humid outside air than if inside air is the source of the air being cooled. mike hunt wrote: > > Just wondering how the AC in Vehicles work. > When you set the Air conditioning to less the max, does The AC still > work > at maximum capacity while mixing the really cold air with some hot air? > If > so, I would say that there is cold air is being wasted. It would > make > more sense to me if AC would turn on and off every few minutes, when > you > have it set to medium cold. > As far as I know the AC is either on or off. There is no such > thing > as partially on. In my house the AC is on max and when the desired > temperature is reached, the AC turns off. Can someone clarify > this to > me? Thanks. |
#6
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On Wed, 15 Jun 2005 18:47:30 GMT, "Jonathan Race"
> wrote: >It's actually more efficient to >run your AC on "Recirc" where it draws in the already cool air from inside >the passenger cabin, and many vehicles these days have a dedicated recirc >button that can be activated regardless of fan speed. But don't run Recirc when temp outside is below freezing. What happens then is the moisture from your breath accumulates in the air and, when you turn off the motor, becomes ice on the interior of the window a Then the next time you run your vehicle the ice from the windows gets into the air and it's a vicuous cycle. F I've seen any number of vehicles over the years where the windows are frosted up all the way around due to this problem. Tony |
#7
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> wrote in message ... > Many home AC system have a feature that shuts down the blower, as > well as the compressor, when the desired temperature is reached. > The HVAC systems in automobiles do not, generally, have that > feature. That does not mean they do not shut down however. The > blower in AUTOMATIC climate control system will cut back but, > generally, does not shut down. The compressor on both manually > and automatic operated systems in cars does shut down when the > desired temperature is reached, then restarts as needed. > Generally, in cars the MAX setting is NOT the temperature > setting, it is simply used to operate the AC in the most > efficient mode by re-cooling the dehumidified inside air, much as > it does in a home AC system. If not set to the MAX setting the > system, generally, is taking in outside air and cooling that air. > When using outside air the compressor operate more frequently to > maintain the same temperature setting because it must cool the > warmer more humid outside air than if inside air is the source of > the air being cooled. > > mike hunt Every car I've ever seen does not cycle the Compressor on and off to control temperature, it does how ever throttle down the blower to lower the amount of air passing over the cooling side of the coils. try www.howstuffworks.com for a breakdown on how A/C works in general. |
#8
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#9
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"Paradox" > wrote in message news:Uh7se.8843$6o4.6276@fed1read04... > > Every car I've ever seen does not cycle the Compressor on and off to > control > temperature, it does how ever throttle down the blower to lower the amount > of air passing over the cooling side of the coils. > > try www.howstuffworks.com for a breakdown on how A/C works in general. > Then you're seeing old GM cars with a suction throttling valve. Some cars also had thermostatically controlled expansion valves. The newer cars cycle the compressor to hold the evaporator temperature just above freezing. Al |
#10
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You have not seen many cars, apparently. LOL
mike hunt Paradox wrote: > > > wrote in message > ... > > Many home AC system have a feature that shuts down the blower, as > > well as the compressor, when the desired temperature is reached. > > The HVAC systems in automobiles do not, generally, have that > > feature. That does not mean they do not shut down however. The > > blower in AUTOMATIC climate control system will cut back but, > > generally, does not shut down. The compressor on both manually > > and automatic operated systems in cars does shut down when the > > desired temperature is reached, then restarts as needed. > > Generally, in cars the MAX setting is NOT the temperature > > setting, it is simply used to operate the AC in the most > > efficient mode by re-cooling the dehumidified inside air, much as > > it does in a home AC system. If not set to the MAX setting the > > system, generally, is taking in outside air and cooling that air. > > When using outside air the compressor operate more frequently to > > maintain the same temperature setting because it must cool the > > warmer more humid outside air than if inside air is the source of > > the air being cooled. > > > > mike hunt > > Every car I've ever seen does not cycle the Compressor on and off to control > temperature, it does how ever throttle down the blower to lower the amount > of air passing over the cooling side of the coils. > > try www.howstuffworks.com for a breakdown on how A/C works in general. |
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