What is the function of dry mode in ac, when to use dry mode, and when to use cool mode and what about heat mode.

not told heating or cooling mode??
or defrost mode (both hot and with AC dehumidifying mode)
no country told or tell what is the weather now , is it hot outside or cold. outside car.??? rain, dry, hot, snow or what> we can't guess this.

does heat only fail or drop out?>
does the blower motor (actually die or go silent) >?
does blower always work on high speed?

not told HVAC mode,so answer are impossible or crazy too long.

AC cooling modes can do that, if the evap core ICE's up.
if R134 refr. is low the evap can ICE up, and and the AC brain detects that and shuts down, until ICE turns to water and drains to the ground under car .
THE PCM can also disable AC cool mode for many reasons.
here are just some
engine EFI PCM shows in distress, lots of DTC errors
Engine discovered is overheated,
engine shows overloaded. (lots of ways)
on climate control versions of HVAC it stops heating and cooling as
this control dial is set to say 75F and that temp is reached.
manual controls have no such dial.

Air dry is a function designed for high humidity countries.
It works much the same as cooling mode only it will run the cooling a lot longer.
I recommend not using it and just use the cooling cycle at a reasonable temperature setting.

When the system cools it removes moisture from the air, some systems will cycle between cool and heat modes to regulate the temp.

The DeLonghi PACA120E Portable Air Conditioner quickly cools rooms up to 400 square feet and comes equipped with several functions that make operation easy and low maintenance. Its 3 operating modes are supplemented with no-drip technology, an adjustable thermostat, 24-hour timer, and much more. This unit truly takes the work out of cooling medium- to large-sized spaces. Multiple Modes and Functions The DeLonghi A120E-also known as the Delonghi Pinguino PAC A120E-offers 3 operating modes and 3 additional operating functions that make this model versatile and energy efficient. Cool Mode: 12,000 BTUs of cooling power help cool large rooms, offices, or basements. Dry Mode: Reduce room humidity by removing excess moisture from the air. Fan Mode: Circulate air to keep your room comfortable without using a lot of energy. Low, medium, high, and an auto-speed are all included (auto speed selects a fan speed for you). Smart Function: Your AC uses Cool and Fan mode based on ambient room temperature. This function will also select your fan speed and keeps your room comfortable without wasting energy. Sleep Function: Using a low fan speed, the AC gradually reduces operation so your room remains comfortable but the AC runs more quietly and efficiently while you sleep. Boost Function: This function is ideal for the summer months and uses the maximum fan speed to rapidly reduce your room temperature. Useful Features Using DeLonghi's patented no-drip technology, this unit is "dripless" under normal conditions, meaning the AC will discharge all of the moisture collected from the air-so you typically won't have to worry about draining the water. When dehumidifying a lot of moisture in Dry mode, excess water may collect in the internal collection tank. Once the tank is full, the air conditioner will automatically turn off to avoid overflow damage. You can also use the included continuous drain hose as a no-fuss way to eliminate excess water as needed. An adjustable thermostat provides additional convenience by allowing you to set your room temperature. The DeLonghi portable AC will cycle on and off to eliminate over-cooling and maintain the set temperature. Additional Features Washable Air Filter: A washable air filter helps remove allergens and other particles from incoming air and saves you money on replacement filters. Quiet Operation: High efficiency compressor and components result in quiet performance. Electronic Controls: The LCD screen displays the timer and temperature settings, while intuitive indicator lights accompany each operating mode. 24-Hour Timer: This feature lets you program your AC to turn on or off up to 24 hours in advance, so it only runs when needed. Window Bracket: Double window bracket is included with purchase for flexible installation. Self-Diagnosis System: The unit includes a self-diagnostic maintenance system that identifies malfunctions should they occur. Remote Control: Use the full-featured remote control to change modes, set the timer, and select a fan speed up to 23 feet away from the receiver (on the front of the unit). Portability: Easy-roll casters and dual carrying handles make it simple to move this model from space to space.

After reading over the Owner's Manual for your unit, I wonder if you are operating it in the Cool & Dry Mode. If that's the case, the dehumidifier is in operation, which would account for having to drain the unit every 2 to 3 hours. Ideally, the Cool and Dry Mode should only be operated for about an hour, when the unit is first started . Removing the humidity will allow the AC function to cool more effectively. But, it is not necessary for it to remain in Cool & Dry mode all the time. Because the AC itself unit will remove some humidity too.

Hope this helped you to troubleshoot and solve the issue of having to drain the unit every 2 to 3 hours

To get proper cold air set temp 23 degree and mode"cool". To get heat set temp 30 degree and mode in "Heat"
Now symbols:
1. fan leaves - Fan only
2. Rain drop- Dry mode
3. Snow flake-Cool mode
4. Sun- Heat
5. A or AU- Auto mode.Helpful?

Symbolsin remote: To get proper cold air set temp 23 degree and mode"cool". To get heat set temp 30 degree and mode in "Heat"
Now symbols:
1. fan leaves - Fan only
2. Rain drop- Dry mode
3. Snow flake-Cool mode
4. Sun- Heat
5. A or AU- Auto mode.

Your AC removes humidity and cools the air, in Dry Mode it cools the air but does not remove the humidity as much, which is OK in a desert (Las Vegas, Arizona, etc.) but not good for caribbean with the high humidity

You need to have an AC tech come out and do some preliminary testing on this.

Hi, I know this question's been up a while and I'm not sure if you care anymore but here goes anyway.

Most air conditioners are reverse cycle, so they can heat the air in your house or cool it down. What we are concerned with is the cooling side of things. So in this mode a working liquid is sprayed into the evaporator and cools its immediate surroundings. air is blown over the evaporator which cools the air. The local temperature around the evaporator is very cold, (how cold exactly I'm not sure) so the air in this region has a very poor ability to hold water and so (especially on a humid day) water condenses out of this air on the surface of the evaporator, is collected and drained away. The cooling function and dry function both use the "cooling" mechanism of the air conditioner. Both extract water from the air in this way but the primary purpose of the cooling function is to cool the air whereas the primary function of the dry setting is to dry the air... obvious I know.

Now in the dry setting the compressor will run with fan going at I imagine a relatively slow speed to chill and extract as much water from the air as possible and to minimise circulation. After a short time the compressor and fan will cut-out and then after a short interval start up again (I'm not really sure but I assume this is either controlled by a humidity sensor OR the temperature sensor monitors for a small change in temperature and shuts off the compressor and fan when it detects this). Now in cooling mode (depending on what temperature is set) the compressor will run for longer and more frequently and therefore remove more water. So why have a dry mode if cooling mode removes more water?... Well that really has the same answer as the question "when do I use dry mode?"

Well on a particular day where the temperature would normally be considered comfortable but on this day it is unusually humid, your body will find it difficult to radiate heat via sweat because of the already high RH (relative humidity) making you uncomfortable and feel "hot". Using dry mode will reduce this RH without adjusting the temperature by much, but you will perceive an ambient temperature drop due to your body being able to discard heat more easily... hence making you more "comfortable" in same way you would normally feel at that temperature.

On the contrary if you were to use cooling mode (which is regulated by temperature) you would have to set a temperature lower than ambient so that the compressor will "kick-in" rather than the air conditioner just running its fan...agree? So that means the air conditioner will reduce RH (which we want) giving you a perceived temp drop but it is also chasing the temperature which you set which will give a REAL temperature drop. So anyway the point is; if it was an unusually humid day on what would otherwise be a comfortable temperature, using cooling (remember the temp has to be set lower than ambient) instead of dry would result in you feeling cold very quickly due to the perceived AND real temperature drop.

So really the dry setting is for days which aren't too hot, but are humid.

I think my logic makes sense.

cheers Matt