Backyard Aquaponics
A place to discuss aquaponics

Hi All,

My tomato plants died due to hot weather. So I have now bought an ultrasonic mist creator and I have connected it with a small fan. It was working great in my room and was cooling really well.

I have created a small greenhouse with just one vent at top. I have put this misting system in greenhouse.

Now when I tried to run it for a few minutes than I noticed temperature not going down and I notice my greenhouse completely wet.

What am I doing wrong?

Do i need to place fan out of the greenhouse to draw fresh air in my greenhouse or what?

Sorry to hear about the plants. Sounds like your humidity was too high in the greenhouse and the air circulation was too low to keep condensation from forming on the walls. Unlike in your room the greenhouse is full of plants which transpire moisture so the humidity was probably higher to begin with. If you keep the air moving it's harder for condensation to form. Another thing to watch for is drips from the ceiling at night because because of water condensing on the glass as it cools. This is a better explanation than I can make -

http://autogrow.com/general-info/humidity-and-vpd

..
But the stated "problem" was the heat, so a mister will just make things more difficult.. simple air extraction is the likely solution..
..
.

Exhaust fan(s) and shade cloth will help, but toms will only perform up to a point in heat. I know when I started getting into upper 90's in GH, they declined. Also depends on variety, some take the heat a lot better then others. Heat AND Humidity...big problem with diseases

The ultrasonic mister creates such small water droplets the evaporate easily and quickly reducing the air temp,the problem comes in high humidity where the droplets cant evaporate and drop onto the surfaces making everything wet,adding the fan spreads the water further.Air extraction doesn't work that well either,if you have a roof vent and vent the bottom of the green house as the air heats up it will exhaust through the vent drawing air into the green house,but if the air your drawing in is at the temps the poster is likely to have 30/35c there isnt going to be much cooling.
If your ok with running fans,try running two both facing in opposite directions,placed at either end of the green house and placed near the opposite corners,when there running this will create a circular airflow in the green house,cooling and improving the micro climate for the plants.

You have exactly stated the problem that I am having. Mist creator is making water droplets of size just 3 - 5 microns. When I place this mist creator in my room then in just a minute it reduces the temperature by 5 C.

However in my greenhouse it made everything wet. I think my greenhouse very small and it needs small amount of mist and i need to place 2 fans to circulate the air better.

I can only talk from basics .. never had the problem... but as stated, of the air being drawn in is as hot as.... then. nothing is going to be really effective..

SOLAR POWER, and an AirConditioner, and a mister comes to mind, but but, what a capital outlay...
All so you can cool it a bit but significantly affect the humidity..
..
.

Okay, so I have installed a really good fan to circulate air so that more water droplets evaporate. However I still see not much cooling. So here are my parameters.

Outdoor Air Temperature - 28 C
Humidity level - 86%

I think misting method is not able to cool greenhouse right now because of high level of air humidity already. We have had lots of rains already in last week.

What do you guys suggest?