Growing Under Lights & Humidity

[brn_thmbs]

Let me preface this post with the fact that I've had my lights setup for all of 12-18hrs and I've never grown anything under lights before.
They are a set of 2 x 4 bulb T5 HO fixtures daisy chained together.

What I think I've noticed is a considerable drop in humidity, even with my small, rinky-dink humidifier running constantly.
Currently I've got them strapped to a shelving unit that's 6' tall x 4' wide & 18" deep (2 shelves filled with orchids of all sizes, shapes, makes and models ) with differing heights for shelves depending on whether the plants on those shelves like lower or brighter light.
Now, I'm planning on wrapping said shelving unit in Reflectix, that's a reflective bubble-wrap insulation, as the setup is against my floor to ceiling patio door and the elements on the other side will turn vicious in a matter of months (think 40mph winds & temps down well below freezing, ah New England). It should also prevent my eyes from bleeding should I walk in to the room at night (man these are bright).

To my question:
I plan on outfitting the wrapped shelving with a heater vent connected to a bucket with a pond fogger in it on a timer, but how long can that wait? The place I'm ordering the ultrasonic mist heads from is out of what I wanted to order for a few weeks and obviously my little humidifier isn't keeping up. Is it a given that under lights a lack of humidity is an increased risk and prevention should be taken to avoid frying your plants or am I reading too much into the drop in RH & I can wait a few weeks to bring in the big guns?

See WIP below: