36
votes
Accepted
A/C loses chill when turning on blower. Why?
Welcome to the wonderful and wacky world of thermodynamics.
A volume of air has heat. For example a gallon of air needs a certain amount of cooling to drop from 87 degrees to 42 degrees.
An AC ...
- 16k
26
votes
Accepted
Would it be harder to install a new AC system if the old one is ripped out already for a long time?
Keep the AC system in the car until you are ready to get it repaired. There's a load of parts to an AC system and some of them are hard to access, you are likely to spend much more in labor costs ...
- 16.2k
22
votes
What is most fuel efficient at 130km/h?
It depends on several factors:
The car's aerodynamics
The AC compressor load
Temperature differential between the desired temp and the outside temperature
The SAE did an experiment, the full results ...
- 16.2k
18
votes
Accepted
Can a car AC unit be run on just the car battery?
I can't give you numbers or calculations without some work, but I can tell you than energy is never free. Cars have an A/C compressor that is mechanically driven by the engine because this is the ...
- 13.3k
17
votes
Accepted
Is it okay or useful to run heat and AC at the same time?
You're meant to.
In fact, in older cars, it was automatic when redirecting air to the window defroster. On this GM control, the far right position would activate the A/C compressor.
Almost always, ...
16
votes
Accepted
What are the dangers of refilling your air conditioner yourself?
What issues can I run into trying to recharge my A/C refrigerant
myself?
The most common DIY problem is overfilling oil, under or overcharging refrigerant and installing the virus that are sealants....
- 11.6k
16
votes
Vehicle AC works initially, but after driving for a while (hour+), the airflow drops to the point being ineffective
The evaporator is the component of the AC system that gets cold. It is located after the blower in the passenger cabin. As it cools the air that is passing over it, moisture condensed on the cold ...
- 24.9k
14
votes
A/C not cold when idling
The AC often relies on the the electric fan near the radiator at the front of the engine bay running to cool the refrigerant. If the fan isn’t running while stationary there won’t be sufficient air ...
- 24.9k
13
votes
Can a car AC unit be run on just the car battery?
Well, Teslas (and presumably other all-electric cars) have A/C so it's not impossible, but A/C takes a fair amount of power.
On the other hand, Teslas store a lot of energy. The A/C is something ...
- 565
13
votes
Using sunshine to cool down the car
If you would like to do that by the use of solar panels, the problem is power.
A typical car AC probably uses somewhere between 1000 and 3000 watts. A square meter of typical photovoltaic cells ...
13
votes
Are A/C Control Panels Universal?
In a word No, not even close. Some are all mechanical, some vacuum, some completely electronic. some are combined with the infotainment device (radio) even the ones of the same type from the same ...
13
votes
What is most fuel efficient at 130km/h?
Keeping a constant speed using cruise control with windows shut and ac on because once the cabin is down to temperature it requires little to keep it there and the ac will modulate its power needs.
...
- 34.6k
12
votes
Accepted
How do A/C professionals dispose of refrigerant?
When I got my Refrigerant Handling Certification from MACS many years ago, we were sworn to use a proper recycling machine, which captured everything and filtered out air, oils, and moisture. The ...
- 12.4k
11
votes
Is it okay or useful to run heat and AC at the same time?
Yes, it is useful, okay and won't cause any damage.
The usefulness comes from the fact that the AC not only removes heat from the air, it also removes moisture from the air (because cold air can't ...
- 14.5k
10
votes
My feet turn black
Cabin filters on modern cars use something called activated carbon (or at least some of them do) which is basically two paper / cotton sheets either side of a fine layer of carbon particles.
It looks ...
- 23.5k
10
votes
Accepted
How to recharge my A/C
First, a word of warning. To do it right (and not waste expensive refrigerant, or risk ruining your A/C compressor), you'll have to get a few pieces of equipment. If you're just going to do this ...
- 1,364
9
votes
Can a car AC unit be run on just the car battery?
The short answer to your question is no. As @JPhi1618 noted, the compressor is mechanically driven. Without the compressor you don't have any cooling. The AC runs by changing the state and pressure of ...
- 9,326
9
votes
Accepted
What temperature should the A/C blow?
Set these test conditions:
Engine set to 1800 rpm
Recirulation air direction on
Fan speed on low
Windows up
Temp set to max cold
Air outlet to dash vents
Vehicle in the shade
Run for at least ten ...
- 11.6k
9
votes
Accepted
What's ECON and how is it used properly?
It probably has a Climate Control unit which regulates the temperature automatically. This means that the air conditioner should always try to reach the requested temperature.
So when it's outside 30 ...
- 288
9
votes
Can running the heater with the A/C on damage your car?
No way. In fact the system is actually designed that way.
The Air Conditioning (A/C) system on your car runs automatically when you are in the Defrost mode. Like you say that setup removes water ...
- 6,569
9
votes
Will running engine after replacing A/C components ruin the new compressor before system is recharged with freon/oil?
Your compressor should be clutch driven. If so, then running the engine won't do it any harm. The clutch won't engage the compressor without a refrigerant charge present. With the pressure at ...
- 153k
8
votes
Accepted
Ford Escort overheats when switching FROM highway TO city driving
A non functioning radiator fan could have those symptoms. In your car the fan is most likely shared by both the radiator and AC. When driving there is sufficient air flowing across the condenser and ...
- 16k
8
votes
Accepted
Low-side and high-side pressures lower than expected after AC repair
That chart is not universal. You should be fine.
Every model will have its own characteristic low-side and high-side pressures.
This is why some manufacturers recommend charging refrigerant by mass ...
- 39.1k
8
votes
Accepted
Does recirculated cabin air pass through the air filter?
Cabin air filters will usually filter the air on either setting if located on the cabin side of the firewall. But even in recirculation mode, outside air will make its way in. Just be sure to ...
- 898
8
votes
Can a car AC unit be run on just the car battery?
Yes, this is possible. Several companies (VAG, BMW) have switched to AC units that are driven by electric motors. For BMW, this is part of their Efficient Dynamics strategy, where they'll switch the ...
- 4,422
8
votes
Using sunshine to cool down the car
You have a great idea! And it IS being done.
Certain models of the Toyota Prius feature an optional solar roof that powers interior fans that automatically engage when the interior gets too warm.
...
- 2,235
8
votes
What is most fuel efficient at 130km/h?
Fuel efficiency shouldn't be your only consideration. Rolled down windows will expose you to noise levels well above 85 decibels which can cause permanent hearing damage with prolonged exposure.
...
- 1,197
8
votes
Vehicle AC works initially, but after driving for a while (hour+), the airflow drops to the point being ineffective
Another answer but less likely the solution is that the inside temperature sensor is faulty or being obstructed causing the system to think it's already cool and turns the fan down and temperature up. ...
- 3,072
7
votes
How do you detect and deal with a refrigerant leak?
A few corrections.
(1) moisture in the system does NOT cause the suction line to frost up on the outside. Quite the opposite. Moisture in the system will freeze at the orifice tube or Tx valve and ...
- 71
7
votes
Accepted
15 ppm of CO levels inside car
This NIH (National Institutes of Health) Study monitoring CO inside the cabin of a vehicle during commutes over an extended period has some pretty interesting data.
From the study
the mean CO ...
- 33k
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