SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

You aren't really thinking clearly on this. If there is an operating fan in the greenhouse, and you want misting to occur when the fan is running, then it's an electrical job. The pieces already exist, and it's up to you to purchase what's needed to connect the dots. If it happens that you are uncomfortable dealing with electricity, then hire an electrician. The manufacturing world isn't going to market non-electrical devices just because that's what you'd prefer to work with.

Purpose is for my small greenhouse. Currently, the exhaust fan turns on/off from an internal theromstat which is used to reduce the inside temperature. Also I have a misting system that I must turn on/off manually, to reduce the temp and raise the humidity. Unfortunately they are two separate systems which operate at different times. I want them to operate at the same time. When the fan turns on I want the misting system to turn, as I may be inside watching a football game.
I want to eliminate the manual operation without opening or accessing the fan controls. Surely there must be a mechanical valve for this application.

If this is a must-have-now situation, use standard equipment, and whatever time and materials are needed to get the job done. If there isn't any hurry, then feel free to invent something, and let us know what you came up with.

What is this "low-pressure misting system" for?

Thanks, sometimes the obivious answer is not always the best. If you are an electrican, don't do plumbing and vice versa.

Good luck finding your mechanical valve. The time you spend searching for it will have been better off spent installing a wired setup.

It can, but I am trying to kept away from trying to find the correct location of the thermostat wiring, also there is no wiring diagram. It would be much easier to use the pressure of the wind from the fan to operate a lever actuator on a valve, or pressure switch. It makes for a much easier installation not to deal with electrical 120v, or 24 VDC, or 12 VDC or try to design the required electrical hook-up/wiring. A mechanical answer is better.

Why can't the thermostat also power a valve?

I looking for a mechanical valve that can be actuate by the wind pressure generated by a fan(fan motor is actuated by a thermostat). In other words, when the fan/motor is turn on by the thermostat, the fan blows air agaiinst the valve actuator, which releases water to a low pressure misting system.