Why does chilled water emerge from the water pipe of air conditioner?

I feel that instead, lukewarm water should come out, the reason being the air conditioner air from the room and also, electricity produces heat energy so as a result warm water should come out. So what is the correct reason for this?

  • 3
    $\begingroup$ What does odor and dust have to do with it? Also, what do you know about how ACs work? $\endgroup$
    – Wasabi
    May 19, 2017 at 20:56
  • $\begingroup$ The water is chilled because it condensed on the chiller. Where else would it condense? $\endgroup$ May 20, 2017 at 9:35
  • $\begingroup$ That is what exactly i was asking that what makes it cool? $\endgroup$
    – user156352
    May 20, 2017 at 10:52

2 Answers 2


An air conditioning system is basically a refrigerator, it passes air over a heat exchanger to cool it ie it injects cold air into a space, it doesn't 'suck' anything out'.

The water which comes out of the waste pipe is just condensed water vapour from the incoming warm air, the waste heat form the exchanger goes elsewhere.


I'm not quite sure of the context of the question or what the water pipeline you are referring to is since most air conditioners that are in homes do not use water, but rather refrigerants. If you are talking about the condensate line from the coil as Chris thought, then yes that is water vapor from the air. Warmer air is able to hold more moisture per volume than cold air and when warm moist air meets the cold heat exchanger (coil) the water vapor in the air will condense on the coil.

As for the sucking out of odors and dust, that is the air return for the air handler that is sucking the air and at the most basic level it is basically pulling air in so that the fan in the air handler has something to blow out. The odors and dust are actually trapped in the filter which is there for the purposes of both filtering out particles for your benefit, but more importantly to protect the coil from all of that crap getting stuck between the fins and making it less effective at heat transfer.

Regarding the electricity, the electricity going into your a/c system is not being deliberately used as a resistive heating element, so the heat generated is only coming off of the motor as a byproduct and is comparatively minimal in magnitude compared to the cooling capacity of the system.

Hopefully that helps and if part of your question is still unanswered, please edit your original question to clarify what it is that you are specifically trying to figure out.


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