I've probably figured this out already, but sometimes input can help clear it up better. I am putting in back-up heating with ventless gas units on the walls through the house. Power outages through winter are deeming this a necessity. I grow my orchids in one room on carts. I'm thinking I'm going to have a problem with fumes and plants. Anyone have any thoughts or experience with orchids and ventless gas heaters? Appreciate very much any suggestions and experiences.