I’m putting together a DIY screenprinting shop in my basement, and one of the components is a drying cabinet for the screens. Blank screens are coated with a thick liquid called emulsion that has to be dried before the next step in the process. A drying cabinet allows the coated screens to be dried while kept away from light, which can harden the emulsion early. To speed up the drying process, a dehumidifier can be used to remove moisture from the air inside. Here’s a good photo of the basic idea of the cabinet.
So I’ve seen a brazillion DIY setups for the cabinets, and they have about a brazillion-1 variations on the dehumidifier setup. They seem to fall in three main designs:
- Dehumidifier outside the cabinet, drawing outside air and venting it inside the cabinet. This makes some sense, as it’s venting drier air into the cabinet.
- Dehumidifier outside the cabinet, drawing air from inside and venting it outside. This doesn’t make sense to me, as I don’t see how it’s treating the air inside at all, and is essentially just acting as a fan pulling air through.
- Dehumidifier inside the sealed cabinet, simply recycling the interior air. This appears to be the most effective, as it’s constantly working on drying the same interior air. And if this is the most effective, would it benefit from having any air flow from outside, or better fully sealed up?
So what say all you smart people? Which variation would be the most effective at reducing the moisture content of the interior of the cabinet?
Option 3 seems to be the most efficient, though that’s just my opinion and not an answer based on any sort of experience with screen printing.
Don’t forget you’ll have to rig up a drain hose for the dehumidifier. 
Yeah, the screenprint info is just for background, I doubt that has any effect of the function of the dehumidifier setup. Thanks for weighing in.
Hey FlyingDragonFan,
I work for a dehumidifier and heater manufacturer and might be able to offer some insight here.
Setup scenario 1 - dehumidifier outside the cabinet, ducted into the cabinet, positively pressurizing the cabinet - This setup would work pretty well if the dehumidifier you use can be ducted. Advantages are the dehumidifier does not take up cabinet space and the cabinet would be positively pressurized, which would help keep dust and particulates out. The dehumidifier should have a high quality filter to make this system work well.
Setup scenario 2 - no benefits for drying. I would avoid this setup.
Setup scenario 3 - dehumidifier inside the cabinet, cabinet is closed, dehumidifier recirculates the air. This seems like a good idea theoretically, but I am concerned that the conditions inside the cabinet will quickly get too hot for the dehumidifier to work properly. Most dehumidifiers do not work well above 90F.
Alternate scenario - have you considered only adding heat to the cabinet? Perhaps a 5,000 BTU heater that positively pressurizes the cabinet? The cabinet would need to be able to release some air pressure (preferably on the top). This would be the least expensive solution and would be almost as effective as Scenario 1 above. The heater should use a high quality filter too.
Let me know if you have any questions or comments.
I have a drying room. The dehumidifier was giving off too much heat. I vented the exhaust out of the room and it seemed to still operate ok and reduced the heart. My partner said I was killing the air exchange and it wasn’t working properly now. I’m confused. If the humidity reduced and the heat problem was gone. What have I done wrong
