Can a sediment filter housing be installed horizontally?

Yes! A sediment filter can be mounted in any orientation, including sideways or even upside down.

However, we suggest that you avoid any orientation other than upright unless there is no other option (like due to space limitations, for example). 

A vertical (upright) installation is always the best practice for easy cartridge replacement! Upside-down make filter cartridge changes messy and more difficult. Horizontal (sideways) mounted filter housings make cartridge changes messy and it is nearly impossible to align the holes in the cartridge with the top and bottom centering posts in the housing.