What kind of misting system is it? there are several different kinds and proper installation would depend on the specific type of system.
Some are direct fed from the water supply, some use an electric pump from a water tank, some use plastic adjustable nozzles while some use fixed brass nozzles.

Also, what are you keeping inside the GH? Tropicals, orchids, seedlings, etc. Placement of the nozzles will also depend on the GH inhabitants.

The misting system is just the black tubing with the adjustable nozzles. I also purchasing fogging nozzles just in case those would be better. I am just hooking it up to a hose. My greenhouse is built on a deck and I raised it up 8 inches so I'm just going to drill a hole the size of the hose connector and bring in the misting system that way. At this point I don't have anything in the greenhouse, but have purchased some roses, orchids and will attempt to grow from seed as well. Right now the greenhouse without a cover can get up to 130. I purchased an alumnet cover but haven't had an opportunity to get a temp. reading. I'm hoping between the cover and misting system I can bring the temp down. Oh yeah, I do have 2 roof vents. I'm wondering if I need an exhaust fan too. There is so much to consider - but I love this!!!!! Thanks so much for your help. This forum is awesome - you are all so knowledgeable and helpful!

I also started with the plastic misting nozzles (Raindrip brand) but I found that the water droplets were too big and ended up acting more like irrigation sprinklers than cooling systems.
Since I keep mostly orchids in my greenhouse, it made the plants too wet and that is not what I wanted.

I wanted the droplets to evaporate in mid-air to cool down the GH interior before the water lands on the orchids.

I switched to the misting system that uses brass nozzles (its a patio misting kit actually - but works a LOT better than the Raindrip). And it ended up being cheaper than the original set I installed. The patio misting kit with 6 nozzles costs like $20.00. I must have spent like $50.00 setting up the first misters - a $50.00 lesson lol. :)

I also have it connected to a garden hose, controlled by a battery operated timer.

You will need some method to vent out the warm/humid air in order to achieve maximum efficiency with the misters if you want them to act as a cooling system.

The principle behind mist cooling is flash evaporation. Basically the water droplets meet the warm, dry air inside the GH and the water evaporates. This cools down the air but increases the humidity. If the humid air is not vented out and replaced by dry air, it will reach a point where the humidity in the GH is so high that the water droplets from the misters can no longer evaporate.

I'm actually using a deck misting system and I had heard about problems with irrigation vs. cooling and someone suggested the fogging heads, so I purchased them. What type of time did you use for watering. That's next on the list.

Thanks.

I'm actually using a deck misting system and I had heard about problems with irrigation vs. cooling and someone suggested the fogging heads, so I purchased them. What type of time did you use for watering. That's next on the list.

Thanks.

During the hot summers I have it set to run for 5 minutes every 30 minutes. Starting from 10:00AM to 5:00PM.

During cool breaks in the weather I can shut off the valve that provides the water to the misters.

smessing, I would urge you to consider the exhaust fan. You will get your temps down just by turning on the fan. Further, as wetfeet says, you need to move the humidified air out and dryer air in for the misting system to be most effective.

As far as timing goes, mine is set for 15 sec every 10 minutes. You just have to fool around with your setup and see what works for you.

SB

What kind of timers and exhaust fans did either one of you purchase. Right now I don't have electric going to the greenhouse - although if I need to I can run and extention cord. Have either of you used solar or battery operated fans. How large does it need to be. Thanks so much, you have both provided me with valuable information.

Smessing, I don't have any experience with solar or battery powered fans, but I am skeptical of their ability to get this job done adequately and reliably. I'm waiting for someone to show me I'm wrong. ;-)

As far as exhaust fan size goes, the widely quoted rule is to size the fan to exchange the GH volume at least once a minute. For a HFGH, a box fan might even be adequate.

Extension cords can and have been used, but there are safety issues to consider...make sure they are rated for the demand and the distance/length...and that they don't become lawnmower food.

Hope that helps.

I have a feeling that will be my option until electric is installed. I have a number of plants I want to put in the greenhouse, but it is sooo hot right now. What type of water timers do you use? I've been searching around and not thrilled with the ones that Home Depot or Lowes offers. I would like to get something quickly.

Thanks