"Steve Barker DLT" writes:
yes, it's fine. it is not 'going back into the air' any more than the water
in the sump would be anyway.

In fact, a wet sump might be a major source of the humidity in the
basement when there is no dehumidifier. With a dehumidifier, you're
ensuring that more of the water remains liquid in the sum, not as water
vapour in the air.

It would save some energy to have the dehumidifier drain into some drain
where it cannnot re-evaporate into the house. But if the sump is the
best drain available, it will work, and the dehumidifier *will* pick up
and re-condense anything that evaporates from the sump into the air.

Dave