When I first read your problem, I started thinking what Ray just said (I think the gas may be methane though).
Humidity could also be an issue. Try growing your Phalaenopsis pots mingled with pots of plants with many leaves, especially high water demand plants (like Spathiphyllum). By grouping plants this way, my indoor relative humidity is typically 50 to 60%.
When I first read your problem, I started thinking what Ray just said (I think the gas may be methane though).
Humidity could also be an issue. Try growing your Phalaenopsis pots mingled with pots of plants with many leaves, especially high water demand plants (like Spathiphyllum). By grouping plants this way, my indoor relative humidity is typically 50 to 60%.
I can't keep my humidity up past 35 most days lately, and I only lost the tiny end buds on one. It's now in full bloom along with a dozen others. Do you give them circulating air and bottom heat?