The JanAire curtain is also called PolyVent

A PolyVent II curtain resembles an inflatable air mattress propped up on its side and encased in a metal frame.

A small, 1/40th, 50 watt squirrel cage blower is connected by a flexible hose to the top tube of the “mattress”. As the blower fills the tubes with air, the”mattress” starts to rise, eventually filling the opening in the building behind the PolyVent II. PolyVent II is normally used on the bottom half of a stacked JanAire unit in dairy barns and is usually operated with an on/off switch.