When considering the location of the tankless unit may variable need to be taken it consideration. Installation of air vent was a little complicated, because the furnace room is located at the center of the house. I had to put a 12 foot extension for Rinnai exhaust. If unit can be mounted on a exterior basement wall is the best solution.
Here are a couple of things to think about.
EXTENSION PIPE
- side wall horizontal venting
- Distance from the tankless hot water unit to the exterior wall
- roof top vertical venting
- For every 4 feet of extension pipe the slope required for water condensation to flow out is 1 inch.
- If the extension pipe does not have enough slope, water may build up in the pipe. Which may cause the pipe to leak water at the joints.
- 2 types of bends 45 and 90 degree
vent pipes come in 3 sizes 10, 19.5 and 39 inch
ELEVATION
- Is the top of the basement ceiling lower than the exterior soil
CONDENSATION RUN OFF
- Will the water condensation flow out of the house or towards the Rinnai tankless unit.
- This will require a condensation hose and trap
