Misting System and Fans: how to mix - Orchid Board

Kaity · #1 02-06-2012, 10:17 PM

Hello Everyone,

I'm planning a terrarium for mini's and was wondering how you all separated your fan from the misting system. I feel like if the fan gets wet it will short. What do you do?

Discus · #2 02-07-2012, 03:38 AM

What I'd do when designing a terrarium, particularly a small onw, would be :
1) use a GFCI/RCD for safety, preferably one per circuit so that nuisance tripping of one component doesn't take everything down.
2) where possible, use low voltage (12/24V) components, particularly in the tank.
3) situate the fans so they don't suck in water (i.e. put misting nozzles in front - rather than behind - fans). Some people create "ducts" that will help move the fans out the way of the mist; indeed, done right, this removes much of the electrical wiring from inside the terrarium and can be hidden in the hood.
4) if I notice a regular problem with fans shorting out or dying, use a relay to turn the fans off whilst the misters are on. This would be a fairly trivial modification - just use the current that feeds the mister pump(s) to open an Normally Closed (NC) relay. The nice thing about relays is that the switching and switched voltages don't have to match, so you can use a 24V pump circuit to switch a 12 or 120 or 240V fan circuit, as long as you get the right unit. I should probably add that you get "time delay" relays, so if the mist hangs about for quite a while after the mister goes off, you can allow settling time.

---------- Post added at 10:38 AM ---------- Previous post was at 10:34 AM ----------

You'll probably also find putting a couple of healthy wodges of some kind of grease into the fan "hub" will help to keep moisture out at some cost to the fan speed. You can also seal any obviously exposed electric bits (like terminals) with either self vulcanising tape or some kind of sealant (epoxy, silicone etc).