I've never heard of such a device, but I suspect it would be expensive if it existed, and, if the motor gave out or the thermostat, then you'd have a pricey paperweight.

I've got a $15 dollar oscillating fan and a good quality, $50 waterproof thermostat: fan plugs into thermostat; thermostat plugs into waterproof electrical box. You're going to have to plug something in, so I don't understand your comment about your outlet box. Here is a link to the thermostat I use. They also carry a similar one for about $30 that you can direct wire.

Here is a link that might be useful: Durostat

fuzzy, kudzu is right about the outlet, but for protecting connections from water, there is an effective cheap trick.

Cut the bottom off of a freezer weight plastic bag, large enough to fit over the plug-in thermostat and the outlet. A 1 gal. size should do.

Then, plug in and seal both ends with whatever is most appropriate to the configuration: tape, twist ties, etc.

My quad outlet box has a clear plastic cover that snaps into place (hinged at the top). It allows enough room to plug a standard plug and route the cable out the bottom of the plastic cover, and water-proofs the outlets. A commercial thermostat would plug into the outlet, then the fan would plug into the back of that same thermostat plug. This stacked-plug creates a plug that is so large that it doesn't allow the plastic cover on my outlet box to close properly. This is why I was trying to avoid a standard commercial thermostat. I've also read that running and extension cord from the outlet to the thermostat plug is not advised.

This sort of rules out the commercial thermostat for my use. I have tested the zip-lock/freezer baggie method and even sealed well, I still get condensation in the bag, so I avoid that method.

I've seen column circulating fans that do have a thermostat, but yes you are correct, they are not cheap. There are also window fans that DO have a thermostat, but they do not oscillate...however there may be some with enough power to simply flood the GH and circulate air. This is also an option.

fuzzy-
I understand what you're saying, but, unless you have a lot of water flying around in your GH, it shouldn't be a problem. I have the same type of plastic cover for my GFCI outlet. And I have two surge protectors plugged into that outlet. The surge protectors are securely fastened in a vertical position to the wall under my potting bench and the surface of the bench is solid, so no dirt or water drops on the surge protectors. I have a thermostat for the fan, three heating mats, and a thermostatically controlled heater plugged into the surge protectors. I've had this setup for a couple of years with no problems. If you wanted to try this and give the setup more protection, you could just attach a small piece of visqueen to the surge protector face to guard against direct splashes; if it just hung there and wasn't sealed you wouldn't get condensation.

I'm concerned about electrical safety around water, but I'm satisfied with this setup, especially since everything is connected through the GFCI receptacle.

Thanks...actually we have an irrigation system and a full misting system (and two kitties) that make it a necessity to keep the box as water-tight as possible. I haven't ruled out a commercial thermostat, but I'm hoping to at least identify some other options.

I just use a cheap fan, let it run 24/7 thru growing season. The one I have is 3 years old. used to oscillate but that part died, mounted it in the ceiling at an angle & it's still running. A little breeze all the time is good for the plants & keep the temp even through the whole GH. Just MHO.

What you need to do is get a thermostat and hard-wire it to your fan. We use Acme's on belt driven large fans and you can place the thermostat anywhere you want. The wiring instructions are included. Acme webpage below. We use the a model similar [or identical] to the T115. I'm not sure of the exact model number.

Regards,

Tom

Here is a link that might be useful: Acme

Thank you...We've thought about leaving the fan run all the time, but unfortunately we pay too much for electricity to go that route. I've looke dinto the hard-wired thermostats in the past. I'm not sure if I have the electrical-talent to cut the power wire from the fan and make that all work. Does anyone know how the wiring would work? Is it as simple as cutting off the fan plug, connecting the two wires inside the thermostat and then buying an electrical w/plug and wiring that into the thermostat also?

Actually, fans don't use much electricity if running all the time; they use the most at start-up, but your mileage may vary.

It is a pretty simple electrical hookup to hard wire the thermostat to the fan. You'll just have to cut the plug off the end of the fan wire and follow the directions that are with the thermostat. Only you can determine if you are able to do this.

Regards,

Tom

With all due respect, a continuously running fan is continuously using energy. They use a little more energy at startup -- for about a second -- but leaving them on all the time unnecessarily eats energy. If you leave a lamp on, or your car idling, or your furnace running 24 hours a day, I guarantee you'll notice the difference.

There is one MAJOR benefit to running a fan all the time....if your greenhouse is crowded and the humidity is high, you NEED good air circulation all the time. If you don't have it, you're asking for trouble from fungus, diseases, etc.

We have a large tube that runs down the length of our greenhouse and it never is turned off. All it does is circulate air--either cool or heat from the furnace.

Ditto for the 6-10 portable fans we have on the tables or floors this time of year in all the houses.

We've found the more air circulation the better.

Regards,

Tom

We will be using a ridge mounted ceiling fan made for outdoor use.

We currently have a unique setup for fans. We have passive vents (2-roof & 2-front-wall.) In one of the roof vents we have a small thermostatically controlled twin fan. I can individually reverse either of the two fans to exhaust or circulate. In the other roof vent we have two large 20-inch thermostatically controlled fans. One exhausts heat out of the roof vent and the other circulates air into the greenhouse. We can controll the speed on these from low to really high...so we do have pretty good air movement. We do mist & irrigate automaically so we do maintan pretty good humidity, but we're not crowded as far as plants. I do want to add a thermostatically controlled oscilating fan if I can find or build one just to add a little movement on a hot day. We're all glass and even with shade cloth, vents, exhaust & misting, it can get hot inside.

Just a quick update...

We still haven't found a thermostat-controlled oscillating fan. We've also done some pricing and an 18-inch or larger oscillating fan is already fairly expensive. We feel a 16-inch won't do the job and we think the size needs to be 18 or larger.

We've started concentrating on wall mount fans to also free up some floor space...but of course wall-mount fans larger than 16-inch are VERY expensive.

We continue to look but we're also considering perhaps just a simple 20-inch window fan (non-oscillating), but powerfull enough to perhaps wash air around the entire greenhouse...not sur eif that will work or if it will just blast things in it's path and miss the others.

Ceiling fans won't fit for us....any othe rideas?

This place offers an outlet cover deep enough to use a plug in type thermostat where you plug the fan into the back of the cord. They also have the thermostats like kudzu9 was referring to.

Here is a link that might be useful: deep outlet cover

Thanks...I'll check it out to see if the deep cover will fit my existing box. With more research, I'm not finding a fan with a thermostat and oscillation so I probably have to run a separate thermostat. We're also leaning heavily to a wall mount fan to save floor space and get the wiring and fan off the ground. These have been VERY expensive in any size over 16-inches. We don't think 16-inches will work well so we're looking for larger. Any suggestions? Most are over $100, some over $200!