I have a brand-new 5000 BTU Frigidaire window air conditioner, and it seems to work fine except that it doesn't reduce the humidity in the room. I turned it on last night, and the temperature was 81 °F with 63% humidity, and when I woke up this morning it was 72 °F with 70% humidity. I thought that dehumidification was necessary in how air-conditioners worked. How could an air conditioner cool the air without removing the moisture? Don't forget that the percentage humidity is RELATIVE. Cold air cannot contain as much moisture as warm air. For the same amount of water in the air, the relative humidity will increase as the temperature drops. By consulting a psychometric chart, I see your overnight run removed 19 grains of water per pound of dry air. If you rewarmed the morning air back to 81 deg F, the relative humidity would be about 52%. Or, if you cooled the initial air to 72 deg F without removing any moisture, you would get a relative humidity of around 88%. So despite the higher relative humidity reading, moisture was removed.

The moisture removed is a function of the temperature of the evaporator coils in the A/C unit and the volume of air flowing through it. As bib pointed out, the unit may not have been actually running that much, reducing the volume of air passing through the coil, and thus minimizing the dehumidification effect.how much for ac unit in house If you continue to cool the same air and avoid introducing additional moisture, the humidity level will eventually be reduced. which ac unit is bestIt will take some patience.window ac unit installation cost Air conditioners need to be sized to the room they are in. The dehumidification process takes some time, so if you have an air conditioner that is more powerful than the room calls for, the compressor shuts off before the dehumidification takes place.