Reducing heat from fluorescent lights

[nicki]

Now that it's summer and the temps are up as I suspected my orchid enclosure is getting too warm. I think I could reduce the temperature if I could put up something to block some of the heat the lights are putting out. I have a 2' 4 bulb fixture.
Has anyone done this with success and have any tips?

[pavel]

About the only options I know of are:

1) LED lamps/bulbs -- From what I understand the tech has finally advanced enough to make them worthwhile. Note, however, that the bulbs will cost quite bit more than the fluorescents -- but they will also use less energy and emit less heat.

2) Increase the air circulations via fans.

3) Install/create vents in the "roof" of your enclosure so the heat can escape.

A photo of your "orchid enclosure" would be helpful.

[Katherine]

Very good advice Pavel!

[nicki]

Surprisingly there is no heat right above the lights. It's all below.
I have 2 small fans and when I put them on high and had them going steady there was little change.
I wouldn't mind the extra heat but I have a couple plants that are more sensitive to temps.
My enclosure is plastic covering a couple shelves. Nothing fancy or nice to look at but it does the job of keeping humidity up. I've tried leaving the plastic open near the lights but then end up losing humidity. I'll work on getting a picture to post.

[Katherine]

If you could also state what the heat and humidity is it would be helpful when you post your picture.

[nicki]

The highest I've seen the temp so far is 88 for the top shelf. I'm sure it's been higher. The humidity is anywhere from upper 50's-80's. When I open the plastic more than what is shown in the picture to let some heat out then the humidity starts to drop pretty quick.

[Katherine]

[QUOTE=nicki;359792]The highest I've seen the temp so far is 88 for the top shelf. I'm sure it's been higher. The humidity is anywhere from upper 50's-80's. When I open the plastic more than what is shown in the picture to let some heat out then the humidity starts to drop pretty quick.

Have you tried humidity trays? Most orchids will be OK at 60% +. I would like to see your set up without the plastic. Where are the shelves? With such a close space in the plastic you may be only circulating old hot air.

[pavel]

Surprisingly there is no heat right above the lights.

Oh believe me -- the heat is there. I take it that the lights are NOT within the enclosure? (Can't really tell from the photo.) If this is indeed the case, it still is not surprising. Think of what it is like to get into a car which has been sitting in the sun. Even on a chilly spring day, it can be almost uncomfortably warm inside the vehicle even though it is chilly outside. An unvented enclosure will always trap a great deal of heat.

I've tried leaving the plastic open near the lights but then end up losing humidity.

Unfortunately, this is always the unavoidable compromise. (For that matter, I have noticed that RH levels drop when one has a fan running.) Depending upon what plants you have in there, humidity higher than 50% may not be all that necessary. Now if you do have some that need it cooler and higher humidity, it might work to have a cool air humidifier at the base of the stand with the plastic raised an inch or so above the floor with some venting at the top (and fans still running. Now I haven't personally tried this, but the idea is basically a chimney effect. As the warm moist air rises and escapes out the top, cool moist air would be drawn up.

[nicki]

The lights are in the enclosure. The copper metal you see at the opening is the light housing. It's hanging from the shelf.
I have 5 plastic containers being used as humidity trays that the plants sit in.
I'll have to figure a way to rearrange things to allow for some venting at the top without sacrificing too much humidity. The plants have definitely shown they like the bump in humidity since I added the plastic.
It could be a good time to rethink how to fix up the grow area. It's one of those projects that started out simple but then you realize you have to keep tweaking one thing and then another and so on.