Hi,

to be honest with you, your best option is to change the lights, If you consider the fact how much you will invest in cooling system I would say GO FOR LED!

With LED you don t have that much trouble plus you save a lot on energy!

I have been using LED for 2 months now, could not be happier, there is not so much to do around it.

That s my honest opinion.

Is the heat from the bulbs or the transformers? I have smaller T5HO's 2 and 3 foot twin bulb and I have no real heat issues at all, Bulbs can be less than a inch from tender plants. The heat I do have comes from the fixture, not the bulbs. I have 5 30 inch LED strips, these put out about the same heat as a 2 bulb 24 inch T5HO.

I have

I have the same problem. I have a soil thermometer and when the lights are on soil reaches 85 degrees. I have four foot, four bulb fixtures and just run two bulbs most of the time. Can't wait till it's warm enough to go to the greenhouse.

You could also use a small clip on fan blowing across the light to diffuse heat. I grow various tropicals under a 400 watt HPS & simply use a fan pointed directly at the bulb works great.