Category III Vent Down

[Scott Latosky]

I understand that the Category III vent is under positive pressure, but is it okay to have the vent going down vertically as opposed to an upward slope? This is for a ceiling hung gas fired heating unit. Thanks for your replies in advance. Scott Latosky

[Phillip Stojanik]

The only way to know for sure is to check the manufacturer's installation instructions for the specific appliance. If you have the model number you may get lucky and find an online version of the manual (assuming you do not have the hard copy available).