What is the Dry setting on air conditioner?
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.
May 30, 2008 |
LG L1204R Air Conditioner