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Hi Doc,

What Nathan says is true, and probably even helpful, but...

I gather by your "warm season" comment that you are interested in mist for cooling rather than propagation. There are a couple of types of system used by forum members. There is the Toro-Home Depot-type mister. These are inexpensive. I tried them. I'd call it more like a fine spray than a mist.

I replaced this system with a system from Hummert. This system uses brass nozzles and 1/2" PVC. I'm happier with this system... smaller droplet size, finer mist. Hummert has a number of varieties, I'm sure they are on the web site. Know your PSI, because some nozzles work better at lower pressures than others.

I use a Phytotronics Gemini 2A two zone controller, it's great, but I think they may have discontinued that model. They still make a 12A 12 zone model as well as single zone models. If cost is no issue, get a good controller. I run the misting signal to a relay and power the solenoid itself with my climate controller. This way the mist comes on periodically only when the GH temp exceeds the zone setting on the climate controller.

Hope this helps. Go Blue.

I installed one from lowes...I have a small GH and heats up quickly....even with the doors open it can reach 120 degrees when it is 80-90 outside....it helped a lot for me...before installing it I would come home everyday to dried out wilting plants...this solved that problem....Last year I ran it for 2 min 4x a day...this year I am going to try for 1 minute.....I did get a lot of alagae in the soil from it....of course in July and August I cant used the GH at all but hey its so nice out and this gives me a good opportunity to do my biannual cleaning..

Steve

steve: have you considered adding some thermal mass - perhaps some steel drums of water, or a bathtub?

Well if I add anymore thermal mass I will have no growing room lol.....Last year I took out my water bottles...which I really havent had enough to make a difference...this year I have a lot more water in there and am thinking of leaving it in for the summer....right now I am pressed for space...I have absolutely no more room...totally packed...at the limit lol....no matter how I re-arrange anything lol..Hopefully in a few more weeks I can temporarily take those water jugs out which will give me more space...I think I will put them back in when the temps get out of control again...

Could you put up a picture or diagram? I'm intrigued as to how you've arranged your water bottles etc. Do you have a fan to blow air through the bottles to improve heat conduction? It may be that the bottles aren't getting the heat fast enough. Perhaps if the bottles are regularly spaced in a grid with a ceiling fan over the top you will get both heat stabilisation and HAF for only a small amount of energy use.

In summer I put some light shadecloth (50%) over my whole greenhouse which is quite helpful for limiting the maximum temp. I just used shadecloth, and sowed a piece of pipe inside it to allow it to roll up when not in use. With a simple arrangement of strings and awning pulleys I can move it up or down in the morning. The strings stop it flapping or moving in the wind (though probably not in a tornado).

I'm not sure how my question concerning a misting system evolved into thermal mass, but if I discover how, I'll let all know. Thanks to you who have provided me with the relevant information regarding misting in the GH.

Does thermal mass help cool? Now I am really confused.

:)

rozy77: thermal mass helps average out temperatures. If you have cool nights and hot days the thermal mass can give you warmer nights and cooler days.

hey Nathan...basically I have a 4x6...On the North wall I have a plastic shelf...no filled with maters...undreneath I have 3 5gal oil jugs filled with water....On the West side I have another shelf packed with plants and water jugs ranging from 2L to 1gal...right infront of that I have another 2 5gal jugs...On my South side I have seeds startin g on 2 shelves with water bottles 2 L underneath....I also have a 2 ft wide by 4 ft high shelves which face the east side water bottles infront on every shelf 2L and plants right behind them...I also have some 2 L bottles not many that are in with the plants...I know a lot of the bottles being shaded, but its not practical to get the most direct sun when my plants would be better off...its getting in the 70,s in there during the day now...been in the 40's outside...and last night it went below freezing outside and it was just above 32 inside..

As for a ceiling fan...I dont want to go through the hassles of pulling a permit, running a line to it just because its tiny..One day when I get a bigger one....wished it was today lol...I will run an electric line to it....it seems to work, not great...but able to keep things from freezing....hopefully this will be our last cold spell...the winter is really getting played out..

Got it, thanks Nathanhurst.

steve: Sounds interesting. Using old plastic bottles is certainly a cheap way to get thermal mass (and you can tuck them in otherwise unused spaces. How much mass do you have in total?

I certainly understand your plight with the bigger greenhouse. I'm currently without greenhouse (although it's nice and warm still so it's not urgent) waiting for council approval of my new attached greenhouse. It looks like we've had our last hot spell, and I've only lost about 10% of my stock over summer, which is good.

roxy: no worries.

I would say in total probally close to 40-50 gal....I have 25 in 5 gal jugs....too many soda bottles to count lol...its definitally not heating it but it is preventing a freeze....I think it is working...I have had repotted tomato seedlings that I started early that are hanging in there,...I took one of each variety in the house the past night just in case...we are having another cold spell...although I must admitt it is very strange walking in a GH covered in snow and things are green in there lol..hopefully it wont last long

Steve

I know this thread is on misting systems, and I'll put my two sense in. I installed a mist system just a cheapie with all the DIG parts, it really cools the GH down. But I want to know more about thermal mass. If I put five gallon buckets on the floor under some benches that I made for flats of plants, will it help to keep things from freezing in the winter and help keep things cooler in the summer? IS that how this is supposed to work?

hi everyone!!! Happy spring!!!
I'm looking into a simple misting system. we put up a hoophouse made of pvc. it is 12x30. I read a post about using a misting mate from walmart. I want to buy the 30ft one, and hang it down the center of the greenhouse. will this produce to much moisture?? we will be starting seeds, and then planting in the greenhouse, like a hot house.
Thanks,
Ginny
please send me an emial to lexonildie8@yahoo.com with your answer if you can.

We built our misting system ourselves from drip irrigation equipment. We're limited for now to timed firing becaus eI simply haven;t figured out how to get it to fire based on tem or humidity. In summer we fire about 5 or 6 times a day for a minute or two, or we can set it to fire for a few seconds every 5 minutes or so. It works great, but does add considerable humidity to the GH which can be good or bad.

As far as thermal mass, we tried a 65-gallon black rain barrel and found it made litte difference as far as heating or cooling in our 16 x 11 GH so we don't bather taking up valuable GH space with any thermal mass.