AC, iam talking Air-conditioning

Using the heat with the A/C on, does that consume freon or whatever that air conditioning stuff is? And whats the purpose of having the AC on while using the heat settings?

Answering the first question will answer this part: Is using the heat without the AC the same thing as using the AC with the heat on?

Does using the heat at all use more MPG? I know that using the AC reduces MPG but what about the heat? or the Heat with AC on?

i know these are some weird questions.. but i always wondered this when i turned 16... which was like 8 years ago, and no one has ever fully answered this question.

 

Using the AC with the heat on does not consume freon, gasoline yes, freon no. Using the AC with the heat will dry the air to help keep windows fog free, this is why the AC runs automatically when defrost is selected. Using the heat with the AC is not the same as using the heat without AC. Using the heat does not increase gasoline comsumption. Using heat with AC increases gasoline consumption. Personally my experience is that extra gasoline consumption due to using the AC is minimal.

 

Car A/C works on the refrigeration cycle. A compressor compresses gas, no longer Freon (CFC-12), but some newer gas more friendly to the ozone layer if it is released to the outside air. The work of compressing this gas makes it very hot (couple hundred degrees?)

This pressurized hot gas is cooled and condensed into a liquid passing through the condenser in front of the radiator.

The pressurized liquid is then routed to the evaporator coil in your car's ducts where it expands at a specific rate (controlled by an expansion valve that senses temperature and pressure) and "evaporates" back to a gas form. The process of evaporation absorbs energy and cools the air passing through the evaporator coil. The gas at this point is routed back to the compressor where the cycle begins again.

While your A/C is running, feel the difference in temperatures of the hoses running to and from the compressor, and to and from the condenser to get a "hands-on" reference. Careful; the hot (high pressure) hose from the compressor can be very hot.

The compressor cycles on and off to keep the evaporator coil at a constant temperature by means of a thermistor which senses the temperature and the ECU which engages or disengages a clutch driving the compressor from the serpentine belt on your engine.

The heater simply routes some coolant after it comes from the engine block through a tiny radiator (heater core) in your car's ducts.

A flapper controlled by the temp nob mixes air from the heater core with the cooled air from the A/C coil to produce the desired output temp.

The A/C requires several horsepower to drive the compressor (when it's engaged).

The heater doesn't use any extra horsepower, it simply uses waste heat from the engine.

A small amount of power is used to run the blower motor.

On cars where the A/C is not integrated with the heater, the A/C temp control varies the temperature of the A/C evaporator coil by cycling the compressor more or less. On the Fit, this has no effect on the A/C's function.

Running the blower fan at a lower speed while using the A/C passes less air over the evaporator coil; as a result it doesn't need the compressor to run as much to keep it at a constant temperature (it's not really constant, but within a certain temp range above freezing). In theory, running the blower at a lower speed will therefore use less power over time (compressor runs less). I'm not sure the difference is measurable in mpg.

For the same reason, running the A/C on recirculate instead of trying to cool hotter outside air also runs the compressor less.

 

Automotive Air Conditioning Systems Air Conditioning Systems

 

thanks guys! iam going to start using the heat with the AC on! i never done it before.