Growing W/ Heat

[AmandaS]

I have 3 different types of orchids- a catt, phal, and onc. I've also ordered a zygopetalum and dendrobium. They are currently growing in a South exposed window, though I also have a North one open, they are both bays. We keep the AC on most the time and it teeters around the mid-low 70's in here. I've researched it and believe the average combined temp for my orchids should be like like 75-85, with a change in night and day temp. As I said, it is usually 75ish, and sometimes it does get cooler at night and drops below 70. Would more heat help them bloom?

I don't want the cold to shock my orchids or interfere with blooming. There is also an AC vent right under the window bay - they get a lot of airflow but might get chilly - though they seem fine right now. I think they get decent sun in the South window, never full hot sun of course (I have burnt one in the past), but could they use some heat? Even just a little grow light with a heat bulb? If I do apply heat, should I do it during the night when it's cooler? Or supplement sun and keep the shades angled during the day? Just thinkin...

[CodiMN]

Good questions Amanda.
I know from other's posts that phals like a temp drop at night in order to produce blooms.
During the day, just from the lights, etc, my 'chids get into the mid-upper 80's during the day and then drop to the low 70's upper 60's at night. They have lots of growth, but no blooming ( I have a feeling they may need more intense lighting). I always have a fan going on the orchids too for air circulation.
Someone once told me their trick to growing phals..."If I'm comfortable, then so are my phals!" As for the catt and onc, I really don't have much to say, so maybe someone else will chime in.

[Ross]

From my experience cool is better than warm for the species you list. Phals are an exception. The temp drop is a one-time thing at fall when temps normally decline. Not every night. Light for Phals needs to be at least 2000 foot-candles (in my experience.) Feel free to place Phals in a south window as long as the light is tempered somewhat by window screens.