Inflated vs hoop-within-a-hoop

I'm wondering, in an inflated poly greenhouse, what purpose the fan serves besides separating the walls of plastic?

Is a hoop house inside a slightly larger hoop house effectively the same thing as an inflated hoop house?  Or is there something I'm overlooking?

Hi K;
I believe the inflated one creates a better insulating layer.

Yup - that's what the tobacco farmer I once rented a house from told me, when I asked about the huge greenhouse, in the same yard.

K Eilander wrote:I'm wondering, in an inflated poly greenhouse, what purpose the fan serves besides separating the walls of plastic?

Is a hoop house inside a slightly larger hoop house effectively the same thing as an inflated hoop house?  Or is there something I'm overlooking?

now if you inflate that outer greenhouse and have another "smaller" greenhouse inside it, you would be jumping like 4 temperate zones when inside the smaller one and 2 zones jump in the outer space. If you kept the inside one heated during the coldest part of winter you could easily grow any tropical fruit you ever wanted on the inside. And possibly citrus in the outer layer if you had enough room, and with the inner section heated it would help the citrus threw the coldest points in the outer layer. But all in all it would be alot of work and extra money for the framing. But I cant say it wouldnt be cool to see....