I’m looking to cool down my greenhouse. I’d like to employ a simple mister on a fan. Every mister I find (that’s cheap) basically hooks up to a hose, meaning it mists continuously. What I’d hope to find is a water valve that is controlled by greenhouse air temp. Basically temps get to 90 degrees the valve opens and starts misting…… temps reach 70 it shuts off. The fan will stay on for continual air movement, just don’t want misting constantly…
Anyone know of a fairly inexpensive solution to this?
Normally Closed Electric Water Shut off Valve, Brass Electric Solenoid Magnetic Valve, Water Inlet Flow Switch Valve for Water Control, 0.02mpa~0.8mpa, 3/4 Inch DC 12V Amazon.com
12v but you can make it work
There may be other ways. I’m just thinking of something I could make easily…
Your up to 50$ max
I think a few of these suggestions will work flawlessly. Though I find myself concerned for your RH if you got flowering cannabis plants in this greenhouse.
@blowdout2269 yes, at the moment the automated fans turn on based on temperature. I’m assuming(hoping) that if the temp setting on the fans matches the mister/fogged timing it will cool the air and vent the humidity. I have a temp and humidity sensor in there and hope to monitor it by that…. And adjust as needed. Kinda a big experiment. But I will forsake the misters and deal with high temps if the humidity gets out of control. And revisit my plans from there lol last year I had pretty good results with pretty high temps… so hoping to increase yield and quality with dropping the temps a bit.
I read that the key to use of misters, is that they need to have very small openings so that the water droplets are tiny and can evaporate before they can land on plant surfaces.
Otherwise pm, mold etc can occur.
@BudWhisperer I do believe they are fog nozzles as opposed to just misters, which implies pretty small droplets. I can always swap out the individual nozzles if it’s too much like a sprinkler
Sounds like a cool experiment! How about using a cheap pressure washer to push your water? That way you get 2000 psi and fogging nozzles should work much better… it does mean some high pressure plumbing though. Also relative humidity is a real limiting factor for evaporative cooling which I discovered when living in a tropical climate, so the lower the rh the better…
Inkbird and a electronic water valve are a good idea for sure, you could also use a thermostatic valve from a heating system, which you can buy in set temp ranges or have them setup custom very easily:
At this point are you just building a small swamp cooler? What about just adding a conventional type drip-pad intake box for your already-automated intake fans?
Our water is pretty hard and the nozzles wouldn’t last long, don’t know if that’s a concern for you or not.
@AzSeaindooin420 does this to good effect down in AZ, I think his GH intake fan is a swamp cooler.
I’m pretty new to all this so not exactly sure what a swamp cooler is. I suppose I should look into this lol.
I think the pressure washer idea may have some merit, but think it may be adding costs, both setup and operating, as I’d have to pay electric fees every time it turned on. Not to mention the noise.
The humidity gets pretty low in the greenhouse. Last summer it was super low RH and very hot. So before investing alot I kinda want to prove the concept to myself. I’ve already spent lot on this project lol my main goal is to hopefully raise the humidity a little (not too much) and lower temps…. Even just a little. My harvest was pretty good last harvest so not complaining, but if I could improve the conditions even a bit I’d be happy. Then would feel comfortable improving the system.
I’m not sure how to make it work, so if you could explain, I’d be grateful 
last year I had pretty good results with pretty high temps… so hoping to increase yield and quality with dropping the temps a bit.
my main goal is to hopefully raise the humidity a little (not too much) and lower temps…. Even just a little. My harvest was pretty good last harvest so not complaining, but if I could improve the conditions even a bit I’d be happy. Then would feel comfortable improving the system.