Greenhouse humidity
 

I am in process of putting up a greenhouse. I will be using a misting system that will mist a fine mist every 3 hours during daylight. Do i have to supplement humidity with a humidifier or will the mister suffice for humidity.

Greenhouse humidity
 

1) Put the mist heads under the benches, unless you're a fan of crown rot. The fans you use for air movement will distribute it evenly.
2) Put the control on a humidistat, rather than timer, and you're all set.


Ray Barkalow
firstrays.com

Ray.
Are you saying to put the mist heads at the bottom of the bench pointing up snd let the fans distribute it. I was thinkjng of buying a system from mist kjng, unless you have any suggestions as to company name and product.

If you're looking to boost humidity, you can simply use ordinary spray nozzles (check out dripirrigation.com), pointed down at the floor, powered by line water pressure, and have a solenoid valve open the water supply to them as the humidistat calls for it. The mist evaporates, and whatever wets the floor does too, without wetting the plants.

If you use something like a Mist King, spraying from overhead, unless you have pure water, you're going to end up with a fine dusty mineral deposit on your plants, and as I mentioned before, you'd probably have to do a lot of experimentation to get the humidity you want without setting up rot in the plants.

I have a Mist King in my basement incubator, and I love it, but it waters the plants early in the morning, the air movement dries them fairly rapidly, and it is quite tight, so keeping the RH up isn't nearly the issue it will be in a greenhouse.

So i would be better off putting a humidifier in the GH to maintain humidity levels and just use the mister to bring temps down in the hotter months of the year.

Humidification and evaporative cooling are not the same thing, and you basically need both.

If you keep the humidity relatively high in the greenhouse, internal misting will do little to cool the air.

The concept of evaporative cooling involves bringing drier, warmer air into the greenhouse and exposing it to lots of water surface area, and as the water evaporates, it takes heat out - cooling it as it enters the greenhouse. In the summer, that will humidify as well, but you cannot use that technique in the winter, as the outside air to too cold.

Bigger windows, more air flow (fan). Ray is right, to much moister just causes rot / fungus. I took off the side panels on my GH and created a full length window with auto-openers on both sides. Talk about airflow! Fresh air is really helpful, especially when it gets hot.