Hi
Well building a window ac with separate in and out. I used metal ducting and thought I could double my dehumidifying by making a insulated chamber on the outside of the hot exhaust duct. Put a fan on 1 side and damper on other side. Then hook fan on a rheostat. Set relative humidity %.
Blow some colder air from ac-ed room and take more moisture out of room with ac running a little longer but not having to run a dehumidifier just a booster fan. to make a pressure change and temp difference; will it ring out more moisture? Also not exchanging inside air with out. Dose this sound right or am I thinking to much. Your thought are greatly respected.
Thank Bob
Hi Bob
Have you built already? Do you have a pic or a drawing? I just want to make sure I understand exactly what you are doing. I'm pretty sure I got it and I like it, basically you are ducting some of the heat back in the room with an electric dampner hooked to a humidistat on the condenser side of the unit? Very good idea I have to say, I never thought of doing that. with diverting some of the heat you can dehumidify 24 hrs a day.....assuming after diverting heat you are still making enough cooling btu's for the room. One problem might be if your humidity stays too high and there is too much heat diverted back in to the room you may not cool enough. Also ducting the window a/c alone will reduces it's btu because you won't be flowing as much air across the evaporator or condenser as it was designed for. That's ok, I would just get a larger unit than what you actually need since it will dehumidify more, this way if you need lots of dehumnidification you will still have lots of cooling btus to battle the heat needed to offset humidity. Just use the largest ducting that makes sense, and build your plenums so that they extend away from the a/c at least 4-6", this will allow for more even airflow over the coils.
Potential problem would be freezing up the evaporator because of lack of air flow, if this happens you may need a booster fan in line to stop that from happening, I wouldn't worry about it unless its a problem, the slower airflow will actually help dehumidify.
Again great idea, we actually have put propane furnaces in grow rooms controlled by humidistats which works really well, and the heat of course doesn't raise the electricity bills. Room heats up, a/c kicks on and dehumidifys, pretty simple.
Show us some pics please :)