I lost the grommet that allows me to attach a drain hose to my air conditioner. So I decided to see whether water's properties of adhesion and cohesion would come to my rescue.
I suspended the drain hose below the air condition drain opening. Then I placed one end of a wet, rolled up paper towel in the air conditioner, touching the drain pan. I placed the other end into the hose. The set up is shown below.
Normally, you'd just let the water drip out onto the ground. But this A/C is installed between a kitchen and a carpeted enclosed porch, and we wanted to keep the carpet dry.
The rig works like a charm. No spillage. All the condensate ends up in the bottle, which I then empty into the washing machine or the garden. In fact it works better than if I'd used a grommet to connect the hose. With the grommet, the water level had to rise high enough to breach the rim of the grommet. In fact, I used to put a piece of cotton string in the grommet to help lift the water up over the grommet ledge and into the hose. Otherwise, the water would leak out all four corners of the pan.
There is some rust forming around the edge of that unfinished knockout. I'll need to paint that at the end of the season if I don't want the rust to spread.