Automatic watering for greenhouse
 

I'm wanting to set up an automatic watering system for my greenhouse (12' x 16') to fill in during the week when I'm short on time or when I'm gone for more than a couple of days. All of my plants are either mounted or Vandas so I would want it to water them at a minimum of every other day and I don't really have to worry about over-watering. My biggest problem with setting something up is my faucet water is too cold in the winter. Would using a 55 gallon plastic barrel with an aquarium heater and a sprinkler pump on a timer work? I'm also not sure about what to use as far as overhead sprinklers. I would want to minimize the water flow since I would be using a reservoir, but I'm not sure the ones used for drip irrigation would put out enough water to keep my Vandas happy. Has anyone else tried to set up something like this? I open to other ideas, especially if they're simpler or cheaper than what I've come up with.

When I had a greenhouse in PA, and was leaving for work at 5:30 in the morning, I watered with an overhead system exclusively.

I had an RO water tank, in which I kept an aquarium heater to warm it to 70F. I had a shallow well pump that provided pressure for delivery through a hose for hand watering, for a fogger, and for the overhead system.

The nozzles came from the Drip Store online, and were low volume "rain" nozzles that attached to saddles on a 3/4" pvc pipe network.

On and off was done with a 110v, normally-closed solenoid valve. When I was home, I turned it on and off with a remote control I devised from garage-door-opener type stuff. For times when I was away, I just used a lawn sprinkler controller.

If you're going to do this, everything needs to be potted up to drain quickly and remain airy.