I recently had a Lennox A/C and furnace installed. The condensate line drips water into the basement floor drain, as my old one did. But now there's also a little side vent in the line that is also dripping a considerable amount of water, and this side vent just drips the water right onto the floor, causing those wet spots that you see in the photo. It doesn't seem normal. Why would there be one vent that goes into the floor drain and another that just drips it right out onto the floor?
You have a new AC system. It's making cold air. It also is making the condensation it produces cold, which in turn creates more condensation in the drip line itself.
Simple fix. Add a series of 90 deg. elbows to the end of the overflow stub. (as shown in blue)
This will make any condensate flow back down the discharge line and being farther distanced from the main line it will not produce as much condensate. A little insulation will help too.
In the event that a large amount of water starts dripping from the overflow stub, you know there is a clog. That will have to be addressed.
As mentioned, it's an emergency overflow. There's probably an incidental amount of condensate that comes out just from dripping down the downspout—no good way to force it away from that side of the downspout. One way to eliminate the output from there but still retain the emergency operation would be to install a P-trap. I like the clear type, like this: https://rectorseal.com/ez-trap-group/ Easy to see if there's sludge in the trap, and easy to flush. This particular one has a float switch that tells you if it's backed up, but you can get them without the switch.
