Moen drinking water filter

[Bbelk]

The new trailer has a filter under the sink the feeds just the one drinking water spigot on the sink. It is mounted flat on the shelf under the sink taking up a bunch of space. There there a reason they didn't mount it vertically. There seems to be room.

[Jammer]

No special reason, it just makes the plumbing a little simpler and doesn't need as many supports.

[Poprivet]

This is a guess.
If the filter is horizontal air might get trapped in the filter causing the water pump to run longer while pressurizing the system which might make you think you have a leak some where.