Hi guys. So I got a small 6x6 greenhouse to keep my 1st year cuttings growing a little longer. I learned quick thru the great info from the members here that without heating the temp in the greenhouse will drop to the outside temp at night so not really helping me out. To fix this I bought a small greenhouse heater which arrives tomorrow. Problem is, the humidity is going so high that condensation is developing on the roof and raining down in the greenhouse. Not going to be good with an electric heater getting wet. Any ideas how to keep the humidity down? I have the vent open. Humidity stays down if I keep the door open, but that will let the heat out too fast when the temp drops.

Just looking for ideas. Thanks guys.

Perhaps rig an umbrella or cover of some type for the heater area.

I probably should do that just to be safe. Did a bit of reading tonight and it looks like basic air circulation is number one. I'll have to get a small fan and get that going soon.

What I experienced in my family's greenhouse is that the heater will dry the air immediately if turned on. We have got an electric radiator and although the temps are @ maybe 40-45° at night (inside the greenhouse in winter) the pots will dry out faster than it is warmer outside and you don't need to heat.

So you probably don't need to worry about high humidity!

Thanks for the input Feiganbaum.  The small heater arrived today.  Now the challenge is figuring out where to put it in the greenhouse.  Its only a 6x6 and the whole space is used by 1st year figs.  Can't have the heater blowing directly on the plants so I'll either have to raise the plants, or raise the heater.

Perhaps the heater on a little table...? The feet of it wouldn't waste too much space.