Gas Tank to Gas Tankless Water Heater - Vent question

[Leo Sangeet]

Hello. I'm new on this forum. I need some help on a project that I'm working.

I have a leaky gas tanked water heater system which I'm thinking about replacing. I've decided to go with Rheem Performance Platinum 9.5 GPM Condensing Direct Vent tankless gas system which comes with 2 separate vents - One for Air intake and other for Exhaust vent. My question is about exhaust vent.

Pictures of my my existing tanked heater vent is attached. Can I connect and vent the exhaust vent through this? Please advise.

For intake air I'll just connect a PVC pipe and use the attic air since I have massive attic which is about 60 x 30 feet and has can and ridge ventilation system.

Regards
Leo

 

[Terry]

You will need to use different material for the vent on this because it's a condensing tankless. The old metal one would quickly rust out.

 

[Sponsor]

 

[Fitter30]

Both intake and exhaust have to be on the same roof or wall for they have to be exposed to the same conditions like wind ( pressure). Manufacturers don't write specs and get approvals for nothing. They want to limit there liability and keep your family safe

 

[Mulligan Stew]

You will need to use different material for the vent on this because it's a condensing tankless. The old metal one would quickly rust out.

Both intake and exhaust have to be on the same roof or wall for they have to be exposed to the same conditions like wind ( pressure). Manufacturers don't write specs and get approvals for nothing. They want to limit there liability and keep your family safe

 

[Mulligan Stew]

Does the low temp exhaust through PVC mean a standard neoprene roof vent can be used? I'm installing a condensing Noritz tankless vent (PVC sch 40 solid core) through a composite roof and would love to simply install the same neoprene flashing that I use for plumbing air vent terminations.

 

[Sylvan]

If you go with plastic make sure it is protected from direct sun light

 

[John Gayewski]

I think your already doing this, but don't use your attic for fresh air. It'll filth up your tankless and make your attic freezing cold in the winter. A ridge vent is only good for so many air changes per hour and it specifically sized (in linear feet) for your attic and insulation for etc.