I like open air and most of my GPUs rigs in the past were all open air, but I agree with the above poster.

Enclosed and closed GPU rigs are better because in the summer the heat won't stay in your house, you basically just use a tube and force the air outside.

With Antminers its easy to force the air outside, you just zip-tie some tubes to the exhaust fans and you are done but you can't do that with a GPU rig thats open air. You can put a fan in front of it and put it next to the window but some of the heat will enter the house. Only way to do it right is to put it in a server 4U chassis and all the heat, except maybe the heat of the case will be exhausted outside and you save on AC costs from heating up your home.