We sit out on the front porch and he can take his oxygen hose out there from the unit inside the house. We have been doing that for some time now. Tonight, he had the portable, large tank out there and letting the inside unit still on. I got upset because that portable tank is for going places, and it costs money. When the unit in the house runs all the time. It's the little things like that that are senseless, he's not thinking, it's costing us extra money and on and on. It's just, I guess, more comfortable with the portable tank, but.