Window Air Conditioner Converted to Dehumidifier Ideas?

I don't know that you have to do anything. The cold side is going to condense moisture no matter what you do. If the evaporator gets down below the dew point, you're going to have condensate running. I believe the dehumidifier units don't really refrigerate down to the point where they're actually doing an A/C unit's duty, but merely down below the dew point and just move the air around. So figure out the dew point, then set the A/C unit to just below that and get some fans circulating the air. Hardest part will be piping the hot air outside. Or just hit a rental outfit and see what they charge for renting either portable A/C units or dehumidifiers. Mop-up outfits use them for drying out places that have had flooding. The portable A/ C units will have plastic ducting to vent the hot air. We had several for the computer rooms for when the big A/C unit went out. They worked OK, but needed some drain hoses for the condensate.
Stan

I'd first remove the covers and hose the dirt and mold out of the condenser and evaporator, then drill a small drain hole in the floorpan beside the condensor coil (the outdoor part). If the schematic is tucked inside remove it first, and don't soap or spray the electricals.
You can buy special condensor coil cleaner which is quite strong. I've had good luck with Simple Green.
Put it on a table with the drain hole hanging over the edge and a bucket, block up the other corner slightly, and just run it. Normally the condensed water from indoors collects under the outdoor coil and the ring around the fan slings it onto the hot tubes to help cool them. You could pour a little water in with the cover off to be sure it drains, without having to run it opened.
When you have it apart and are playing with it, don't turn it off and then back on quickly. Like an air compressor they don't start easily against pressure. I cleaned mine a few days ago, and tested it with a 3750W generator. The normal starting surge read about 10A, but when I turned it off and back on the ammeter read 25A and it loaded down the genny and wouldn't run.
jsw

Just turn on the window AC with it all in the room -- nothing sticking out. One end would be pumping out cold air, the other end hot air. Overall, it will raise the temperature a little, but pull a lot of water out. (You'll need something to catch the condensate, of course.)
Set up the other one through the wall, so it cools and pumps the hot air out side. That one you can use to get rid of the excess heat from running the first one totally inside.
Good Luck, DoN.

you may need to add drain holes as mentioned earlier in the post.
lots of "newer" window units are designed to collect a puddle of water which gets splashed/blown around on the condenser coils to help cool them.

That's essentially what I was going to write. I'll change a few words.
======================== I'd first remove the covers and hose the dirt and mold out of the condenser and evaporator, and clean out the pan that holds it all together.
The cold coil that faces indoors, absorbs water from the air. Sometimes they drain into the pan via a rubber tube.
Drill a drain hole in the floorpan toward the back of the unit. If the evaporator drains through a rubber hose, drill a hole to allow the hose to drain through the metal tray.
If the paper schematic is tucked inside remove it first, and don't soap or spray the electricals.
You can buy special condensor coil cleaner which is quite strong. I've had good luck with Simple Green. Actually, simple green is really excellent coil cleaner.
Put it on a table with the drain hole hanging over the edge and a bucket. A couple slats over a laundry sink or sump pump is much better. block up the other corner slightly, and just run the AC.
Normally the condensed water from indoors collects in the meetal tray, and the ring around the fan slings it onto the hot tubes to help cool them. With your modification, the water drains into yoru bucket or drain.
You could pour a little water in with the cover off to be sure it drains, without having to run it opened.
When you have it apart and are playing with it, don't turn it off and then back on quickly. Like an air compressor they don't start easily against pressure. I cleaned mine a few days ago, and tested it with a 3750W generator. The normal starting surge read about 10A, but when I turned it off and back on the ammeter read 25A and it loaded down the genny and wouldn't run.
(Actually, very well written commentary, thanks. I have modified both AC in my trailer to drain, and not to spray the condensor. It's usually so humid here (Rochester, NY) that the spray only collects dust.

Thanks all. Read the advice and went out to look them over, to find both on their sides. set them upright on a work bench and waited 24 hours, then side tracked for a couple of days. Both work, but the real heavy one worked the best. Side tracked another couple of days and then took it apart, wow, the dust and acorns where everywhere. It is now dripping like crazy outside and soon this clammy feeling will go away.
As for the room, the weather changed that day and I hung up really thin plastic.
SW