My SIL gifted this to me. It belonged to his father who recently passed away. @Eric4home any ideas on venting behind it to allow more air to come in? Its already sucking all my bubble wrap insulation. I want to build a (strong) platform for it. Right now it takes up the space of 2 large plants. If I raise it up off the ground at least there will be room for plants underneath this winter.

Can you remove a panel and build a frame with screen for summer use? Does it have a slow speed so it mixes and pushes the air rather than blow you out the door? I have a backdoor (painted plywood) in my GH that I just remove for the summer. That and my small turbo fan on the floor pointing straight up do a far job for me. I use the turbo year round to push the cool air up and mix it to prevent the heater from running with the vent open.

Thanks Ric. @Eric4home Ahhhh! I now recall your door or something with a cool handle on one of the panels. The back panel is the tallest panel of them all. I can remove it easily enough. I will search for your post about the door as yes, this is something I would only do in the summer. As wide as the fan is (4 ft.) I should probably cut three panels. Is the poly panel easy to cut? With an Exacto type blade? Saw? Or??

The fan has no knobs. You plug it in and it goes. I think I could add a switch to the plug. But I dob't think I want it plugged in all the time. Just when it gets really bad inside. It's belt-driven is all I know. It is not totally a wind tunnel but when it's 100 degrees in there, feels really good! I guess when I expose it to more air, it will blow more? As you may recall I do not have anything in the GH in the summer. But it does get very warm in there in the winter and I need more air circulation than my little box fan gives. I also to repotting in there so I am inside it a lot. I will first think on the platform to raise it somehow. Then go from there. I think that generator in the corner is suddenly taking up too much space! Into the garage it goes!

Cheryl, If it is belt driven you can possibly change the speed by changing the pulley om the motor. A large slow fan is excellent for air circulation. There are generally 2 speeds to motors 1725rpm or 3450. If yours is 1725 all the better, if you have a 3" or larger pulley on the motor you may be able to get a smaller one at Ace or such. If there isn't enough adjustment on the motor mount you may have to get a larger belt.
building a frame for it is a good idea, and would make it easier if you wanted to move it.
Polycarbonate Can easily be cut with a square and an Exacto knife. A strip of foil tape would effect an over winter repair to put the panel back. If you worry about critters getting in, (I don't have a problem) , you can make wooden frames with hardware cloth or screen to fit your frame.

Ric @Eric4home I think you may make a mechanic out of me yet! I see how a slower fan would make a big difference. My plants like circulation, but maybe not windy conditions. I am going to investigate this. My SIL will be coming back to Texas whenever the Navy lets him. He still has a lot of his father's things to sort through. Maybe if I get all the parts together, give him a heads up and buy him dinner, he can help me. He is very mechanical. Me, not so much. But I think you will have me up and running with the best of them at least with pulley engines! I'll post some photos next. I am not sure what I photographed. But it has two belts. Maybe you can see what's up? I appreciate you!

Looks nice man, what are you going to make with it?