Some notes on screen rooms:
1. If you add diazo to your emulsion try to keep the room at 80 or below. Over 80 degrees effects the diazo and 'dark hardens' it on a coated screen and in the bucket. This shows up as a screen where it is difficult to develop the image and usually there is some edge quality loss. Air conditioning helps, I'd like to know more about the split units or even a photo of one, I've never come across one and they sound like a good tool for screen rooms.
2. Yes it can be too cold in a screen room as well. Emulsion will get much more viscous in cold conditions. Coated screens can also get too dry. The winter cold weather drops humidity a ton and can make the room so dry emulsion will crack during the printing process. 35% humidity is a good balance. In winter you can run a small vaporizer to bring up humidity to 35%, Hot humid conditions may need a de-humidifier depending on the location of your shop.
3. Very hot humid rooms are tough to dry out. High temperatures make it harder for the dehumidifier to work, using air conditioning helps bring down temps to where the dehumidifier can pull more water out of the air.
4. 70-80 degrees at 35% is the target. Vapor barrier doors like those used in super markets help keep wet air out, dry air in.
5. A moisture meter is the easiest way to know if your climate controls are working. They aren't cheap, but a good moisture meter like we sell and use in our demos tells you exactly when the screen is dry to shoot. This tool helps make the screens predictable in terms of durability on press. Some screen rooms need to dry 20-XX screens to prepare for coating. This moisture in the screen room and it gets soaked up by coated screens. With a moisture meter you can measure the screen to see when it has re-dried and is able to shoot. Sure it will feel dry all the time, but the moisture it soaks up when wet screens are brought in can take 15-30 minutes to return to the dry reading on the moisture meter.
