(Zigo + Onc) - HR = Poor growth

[rbarata]

Hello, my friends

Now that temps are over 86 F (30ºC), with a forecast of 99 F (37ºC) next week, humidity is going down as usual (today with have something like 16%).
This is posing a problem for my zigo and my oncidium. While the zigo has been growing poorly, the onc is growing nicely but with its leaves all curled.
The place where I have them, in this time of the year spring / summer) has an HR between 20~30% and it doesn't go higher than this.

I need some ideas to solve this problem. Misting and water trays doesn't seem to be a solution.
Enclosure them? But how?
Water culture?