Air conditioning more economical to run manual or set temperature at 77 on front vent recycling air?

[Tbone289]

That's exactly how I think it operates.
You set the manual fan speed it does not change. It operates at that setting constantly.

You set the fan speed using the auto button 1, 2 or 3 and that's the maximum speed that the fan will go. It may adjust lower as the interior cools and then it will speed up to the maximum that's been selected, if it needs too.

Therefore, in my simplistic logic. I think Auto setting is actually the more economical setting electricity wise by a minuscule amount.
The AC compressor is going to cycle off and on, with either setting trying to maintain interior temperature.

That is a bit too simplistic. Most auto HVAC units don't cycle on and off based on the interior temperature, they cycle on and off or modulate variable compression to maintain proper pressure in the system and humidity level in the cabin. Blend door actuation is typically what is used to maintain a set temperature.

So, the question should be: is the manual setting monitoring interior temperature and compensating for the reading as the auto setting does, or is it just setting the blend door at a static setting based on where you have the temperature set as a truly manual HVAC temperature setting does? This may not be difficult to prove, as I think the door actuators are fairly easy to visually monitor with the glove box door removed, at least on the Ecoboost Maverick.

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[Glen Baker LLC]

Most auto HVAC units don't cycle on and off based on the interior temperature, they cycle on and off or modulate variable compression to maintain proper pressure in the system and humidity level in the cabin. Blend door actuation is typically what is used to maintain a set temperature.

So, the question should be: is the manual setting monitoring interior temperature and compensating for the reading as the auto setting does, or is it just setting the blend door at a static setting based on where you have the temperature set as a truly manual HVAC temperature setting does? This may be fairly easy to prove, as I think the door actuators are fairly easy to visually monitor with the glove box door removed, at least on the Ecoboost Maverick.

Does the fan speed vary in auto mode?

 

[Tbone289]

Does the fan speed vary in auto mode?

Yes, it does. The three levels of auto mode set the maximum fan speed at low, medium, high settings. As far as I know, that is the only difference between those three settings--the maximum fan speed the system will allow. The system varies the fan speed based on interior temperature up to the limit you set to maintain temperature.

 

[Glen Baker LLC]

Yes, it does. The three levels of auto mode set the maximum fan speed at low, medium, high settings. As far as I know, that is the only difference between those three settings--the maximum fan speed the system will allow.

I thought so that was actually the point I was trying to make.
Thank You.

 

[Tbone289]

I thought so that was actually the point I was trying to make.
Thank You.

That makes sense now that I re-read your post and thought about it some more. Whether you're using manual or auto to maintain a specific temperature, the difference in power consumption is really only going very minor variations in fan speed. You're probably better off allowing auto to do the work for you. That's what I do, because any very minor difference in power consumption is worth it in comparison to the extra work required to manually make adjustments and the distraction away from driving of having to do so.

 

[KO Stradivarius]

I am good with windows down until 50 MPH when the wind noise becomes bothersome. I don't want the AC to where out prematurely.

I also don’t like warewolves or cookwear

 

[KO Stradivarius]

That's exactly how I think it operates.
When you set the manual fan speed it does not change. It operates at that setting constantly.

When you set the fan speed using the auto button 1, 2 or 3 and that's the maximum speed that the fan will go. It may adjust lower as the interior cools and then it will speed up to the maximum that's been selected, if it needs too.

Therefore, in my simplistic logic. I think Auto setting is actually the more economical setting electricity wise by a minuscule amount.
The AC compressor is going to cycle off and on, with either setting trying to maintain interior temperature.
The temperature you set is going to be the biggest factor in how much you save.

Not sure which is more economical. I would think Auto probably is because it uses a computer chip to adjust the parameters constantly, while manual relies on you to do it. I agree the temp setting is the key. But I just don’t want my plenum door motors burning out again, so I will choose manual.

See Link:

Auto AC takes over the management of your car's climate by using cabin sensors to automatically adjust fan speed, air distribution (vents vs. floor), and temperature to reach your set target. Manual requires you to adjust the temperature dials, fan speeds, and airflow directions yourself as conditions change

 

[Glen Baker LLC]

 

[HeyBales]

From how I understand it the temperature set is always automatic, you set a desired cabin temperature and it tries to maintain it. The auto mode just operates the fan speed and directs the air where it thinks it will be most effective.

Or am I wrong, and the set temp is what is supposed to come out of the vents no matter what?

Not in a house, nor in the car - is the Set temp supposed to be the air temp coming out of the vents.

You are correct.

 

[KO Stradivarius]

Not in a house, nor in the car - is the Set temp supposed to be the air temp coming out of the vents.

You are correct.

I believe the temp setting is the desired cabin temp, as the interior sensor is reading. That’s how a thermostat works. The air temp at the vent is like upper 40’s or low 50’s in my truck if set to “LO”. I keep a thermometer in the vent at all times.

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