Vent

The tankless heater is one SKU and the installer can choose how they want to vent it.

DV

The default vent configuration is 2 inch diameter up to 65ft.  You can adapt a 2 to 3 inch coupling and run the vent up to 150ft.  The air intake pipe can be routed the same distance and it doesn’t matter that the two pipes run to different pressure zones. One can go up through the roof and the other out the side wall though it is common to route both to the same plane.

SV

In cases where its not desirable to draw combustion air from the dedicated air intake pipe, the combustion air can be collected in the area of installation like a garage, or a large basement, or in a mechanical room with circulated air.  A SV conversion kit, which is a 90 street elbow with a birdscreen can be adapted to the intake pipe to protect the tankless combustion air from contaminants in the area of installation.

OD

In warm climate regions where it does not typically snow, the tankless heater can be installed outdoors with an outdoor vent cap.  The critical clearance distance to remember is to keep the exhaust a minimum 4ft away from operable doors and windows that are above or to the side or 1ft away if the door or window is below the exhaust.

Flex

The flex vent option takes into consideration that 90% of existing water heating is completed by a storage tank and to facilitate an easier transition from tank to tankless, it is possible to utilize the existing utility connections and vent stack to install a tankless heater in the same location as the tank being replaced.  This configuration saves on installation time and gives the end user piece of mind to install tankless as an emergency replacement to try it and like it.  But on the rare chance they want to go back to a storage tank, the end user can.