Condensation in Laser Cabinet

[Bob WrightNC]

Anyone else walk in to see the inside of your laser wrapped up in condensation? The vent to the outside is creating real moisture problems in the cabinet when the AC is wide open. Leaving the lid up and drying out best as possible.

[Bill George]

If your meaning the vent to the outside is allowing warm air into your machine. Then put either a manual damper in or a gravity closed vent door on the outside, like your dryer vent has installed.

[John Lifer]

nope, But I have a sliding damper that I close most every night. Usually relatively dry here, but not this summer.

[Kev Williams]

So the outside vent is letting in warm humid air. I'm thinking the bigger problem is the "AC wide open"- if condensation is forming on the inside, then the cabinet is too cool.

The fix is, turn the AC down, especially at night so the cabinet doesn't get too chilled; keep the blast gate on the vent closed to keep the wet outside air out, and keep the LASER wide open, so any outside air that gets in can escape and mix with all the other air in the room, and to help keep the entire laser box inside and out the same temperature. As long as the laser cabinet and the room air is the same temperature, you can't have condensation...

If you NEED the AC on full blast, put a good old fashioned 40w incandescent trouble light inside the laser with the door closed, that should keep the cabinet warm enough...

[Bill George]

It would of helped to know you already had a damper closed. Warm air hits cold air equals condensation. Turning the AC warmer would help at night but if your in AZ and its 120 daytime outside or its a little undersized then you need it cool to start out in the morning. My best guess from a HVAC guy is you have an exhaust fan in in the building somewhere and its drawing air past your damper or your damper is poor quality and not sealing tight.

[Mike Null]

Bill George has it right.

You can also put a blast gate at the exhaust outlet on your machine. You can usually find them at woodworker's supply stores.

[Bob WrightNC]

The blast gate is a good idea. It's been particularly humid this week in NC and, while the thermostat is set to go up at night, it's still not enough to compensate. I've resorted to leaving the top open for now. The vent system on the roof is an open j-hook with 4 inch PVC which is where and why the humidity is getting down here in the first place. Got to admit the first time I saw all that humidity, I pure panicked about the electronics in the laser - opened it up and cut the exhaust on for about 30 minutes to create some airflow. Powered up no problem. Sometimes it's the things you don't think of that get you.