orchid room-temperature problem

[brit6v]

Hi,
I have a new orchid room....it's 9x9x10' with 2-4', 4 bulb, high output T5 fluoresent grow lights. At 24", the heat on my leaves is approx. 87-90 degrees, so I cannot bring the bulbs any closer to the plants in order to get the footcandles I need without burning the leaves. Since I need to cool the temperature down, I have been checking to see what my options might be. Has anyone had any experience with an evaporative cooler (swamp cooler)....or do you have any more ideas? If so, I would appreciate your help.
Thanks in advance,
Vicki

[Becky15349]

Is there good air circulation in the room? That seems a little hot for grow lights...maybe you can open a window in the room and get some fresh air in there. Also, placing fans so they are blowing lots of air around the leaves will help prevent burn.

[brit6v]

Hi Becky,
I just replied to a post from Ross about fans. I doubt that your have had time to see it because I replied only a couple of mins. ago. Here's what I told him:

[FONT="Georgia"]
I already have a large floor oscillating fan inside the room (I'm sorry, I should have mentioned that in my question post). The room has no windows and adjoins the garage. When the grow room temperature gets extremely hot, I have to open the door and place an extra fan there in the garage facing the inside of the grow room.....another large floor oscillating fan. That leads to another concern: I also have a humidfier in the grow room, but it can't keep the humidity up in the room as high as it should if I have to open the door into the garage. I have been trying to research evaporative coolers online, and have found they are used in greenhouses, but I didn't know if one would be suitable for such a small area as my grow room (9x9x10'). I had in mind a small portable one, but I wanted input from all of you before I purchased one.
Thanks again Becky,
Vicki

Is there good air circulation in the room? That seems a little hot for grow lights...maybe you can open a window in the room and get some fresh air in there. Also, placing fans so they are blowing lots of air around the leaves will help prevent burn.

[Ron-NY]

Vicki, I think a fan blowing across the plants should solve your problems. How high is the temp of the room getting? I assume the temps are just high under the lights. A small, desktop fan or even a plug in muffin fan blowing across, in the space between the lights and the plants, should move that heat away from the plants. Now 24" for a T5 set up is not a bad distance unless you are growing Vandas. There are other options, if you own you could put a bath exhaust fan between the room and the garage and exhaust some heat out of the top of the room. It would need to be hooked to a thermostat so it only cycles on when you need it.

I just purchased a 4 light T5 unit for an "orchid spa" that I am going to build this winter. I do plan on having the unit shine into the glass case but not be inside of the case.

[brit6v]

Hi Ron,
I already have a large oscillating floor fan inside the grow room, blowing on the plants and under the lights, but that doesn't seem to be enough to keep the temperature under the lights down. At this time of year here in Alabama, the ambient temp. of the room is approx. 85 degrees on an average, so you can only imagine how hot it has gotten there in the room this last summer. Terrible. The temperature under the lights is from 3-5 degrees hotter. I can get no more than 1000 fc at 24" from the lights to the leaves, which of course you know, is not enough for some of the orchids I'm trying to grow (catts, for example. I won't be trying to grow Vandas since I know I cannot provide the adequate conditions). Bottom line: I can't move my lights down closer to my plants, as I would like to, in order to get the amount of footcandles I want, or else I would burn my orchids bigtime.....so that's why I've been thinking about an evaporative cooler. My only hesitation in purchasing one is that I wanted to be sure that someone else may have done so and realized some problems....maybe mold, for example, or whatever??.....or hopefully no problems. Just a thought.

I would appreciate any other thoughts you or anyone may have, so I'm hoping to get more of your input.

By the way, I'm sure your orchid spa will be so nice! I wish you the best of luck getting it all assembled.
Thanks,
Vicki

Vicki, I think a fan blowing across the plants should solve your problems. How high is the temp of the room getting? I assume the temps are just high under the lights. A small, desktop fan or even a plug in muffin fan blowing across, in the space between the lights and the plants, should move that heat away from the plants. Now 24" for a T5 set up is not a bad distance unless you are growing Vandas. There are other options, if you own you could put a bath exhaust fan between the room and the garage and exhaust some heat out of the top of the room. It would need to be hooked to a thermostat so it only cycles on when you need it.

I just purchased a 4 light T5 unit for an "orchid spa" that I am going to build this winter. I do plan on having the unit shine into the glass case but not be inside of the case.

[Lizgeo]

I don't think a few degree higher than 85 is too hot for orchids. I grow them outside in Houston. Summer days here are often hotter than 95, sometimes reach 100. I have two small clip-on fans on 24 hours for the orchid shelf.
If I were you, I would try 1 year without cooling system to see if you really need one. Fall is almost here anyway, you don't have to worry about high temp for a while.

[brit6v]

Hi!
The temps from the lights to about 6-8' from the top of my orchids ran somewhere around 87-90 degrees today. I've never thought about what you said....about the high temps outside this last summer. There were quite a few days here as hot as yours, so I'm gonna try not to be worried about high temps in my orchid room.

I like your idea about the clip on fans. I'm thinking about either doing that or mounting small fans on the walls....pointing just beneath the lights then point my floor oscillating fan on my plants.

I've been thinking, and doing a little more online research about evaporative coolers. I understand better now how they work and that they wouldn't operate as efficiently in Alabama weather as they would in a less humid region.....so I've decided against using one. Also, as you said, Fall is almost here, so we won't have to worry about high temps soon.
Thanks again for your help,
Vicki

I don't think a few degree higher than 85 is too hot for orchids. I grow them outside in Houston. Summer days here are often hotter than 95, sometimes reach 100. I have two small clip-on fans on 24 hours for the orchid shelf.
If I were you, I would try 1 year without cooling system to see if you really need one. Fall is almost here anyway, you don't have to worry about high temp for a while.