I grew up in Texas and still have family there - will be in Austin 4/23-4/30. Think those folks with greenhouses use evaporative coolers - there are two commercial firms in the area - It's A Jungle in Austin and Miller's Tropicals in Dripping Springs. Down Houston way are Clown Alley Orchids and Stephen Moffitt (he's on Facebook and I think he's growing in a shade house) Good luck.