Which vent pipe kit is used for the Modine HDS30, with concentric kit attachment and what is the cost?

Hello, thank you for reaching out. When choosing which concentric vent kit to use for the HDS30, it depends on the type of installation...For horizontal installations, use the 3-Inch Horizontal Concentric Vent Kit (Model 77792), priced at $285.00. For vertical installations, use the 3-Inch Vertical Concentric Vent Kit (Model 77793), priced at $375.00. If you have additional questions, please feel free to reach out over the phone to our Customer Service line at 1-888-901-5460. Have a great rest of your day.