Swamp coolers vs. High pressure misting

[Duck Slipper]

Hoping to pull the trigger on a greenhouse in about two months. I don’t think fans and shade cloth can keep a gh cool enough in Kentucky summers. With that said for $1000-$2000 a good evaporative cooler can be bought...also a high pressure mist system.
I’m wondering what people opinions are of each? Pro’s and cons.
Also when using either type of cooling, what about ventilation, fans and shade cloth. Fans to remove hot air from the house AND the cooled air.
I have read lots of negative comments about swamp coolers. Mostly concerning maintenance with pumps going out and replacing the pads. High pressure misting...not so much. Thanks for any and all opinions. Duck

 

[Ray]

My opinion - having had greenhouses in LaGrange KY, Georgetown SC, Jackson NJ and Doylestown PA - the two achieve different outcomes.

Misting raises the humidity in the greenhouse. That cools at first, but once a high RH is achieved, there is no cooling. after that, it mostly wets the plants, potentially leading to pockets of microbe incubation (rot). If active exhaust fans are used, that is minimized.

A swamp cooler has its own blower, so pushes cooled, humidified air into the structure. A wet wall-type cooler relies on exhaust fans to pull air through the pads. The later case results in more overall air flow through the greenhouse.

However - if exhaust fans are used, either one can work.

My preference, having done both, is a wet wall.

 

[Ozpaph]

Like Ray says. They do somewhat different things. I run the evap cooler on a thermostat so it may be on for many hours during the day. The misters come on and of on a timer to keep the humidity up - would be better on a proper 'humidistat'. Too wet/too high humidity and high temps is a recipe for rot. Try to control both independently AND lots of air movement.
Aluminet ABOVE the shade house works. Light coloured shade cloth is also beneficial.

 

[Duck Slipper]

Thanks Ray and Ozpaph...Appreciate the input!