Combustion Condensate Question, Help me learn!

[Erby]

8 year old Rheem Gas Furnace and 8 year old Bradford White 40 Gallon Gas water heater are in a closet in the basement (with four louvered doors & plenty of combustion air). Closet is located, in the basement, about even with the right upper level window. Flue runs thru a chase and then vertical to the right side over the garage.

(2nd story flue is for attic furnace and not part of the question.)

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Water heater flue connects with a T instead of a Y. Lots of combustion condensate drippage.

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The ceiling (bottom of the flue chase) where the flue goes vertical has been water damaged & repaired (combustion condensate is my guess because I got on the roof and didn't see any flashing problems around the flue on the roof)

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So I told her to have it fixed by a yada yada HVAC guy.

But, for my knowledge, how would you HVAC gurus fix it to eliminate the combustion air condensing and leaking back into the house?

[hausdok]

Hi, it's hard to say from just that little picture, but I'm thinking they equip it with a power vent and run the flue out the side of the house at basement level instead of winding it through that house and out the roof so far away.

ONE TEAM - ONE FIGHT!!!

Mike

[carle3]

The angle of the picture could distort this a bit, but that extension above the roof looks a bit longer than it needs to be. Couple that with the run through the cold air cavity and a mid-efficient furnace and you get gases cooling and condensing before they can get out the flue. That run needs to be reduced, if possible. This installation would be better suited to a power vented water heater and a high efficiency furnace vented with PVC. Replacing the appliances may be the only fix.

[Erby]

Thanks, Mike and Carl. Anyone else?

Is there a retrofit for adding power vents to existing furnaces and water heaters.

[Chad Fabry]

It's going to be difficult to fix with the existing configuration. The water heater doesn't generate enough heat or volume to prevent condensation once the exhaust is in the furnace sized flue.

What Mike said... power vent the water heater , get a direct vent unit or switch to electric.

[Jerry Simon]

Building an insulated chase around the attic flue pipe section has been known to help (assuming there is a *cold* attic through which the flue passes).

[msteger]

Since these appear to be 90%+ condensatings unit's, run these to the outside w/ PVC from the appliances. No need for metal flues.

[hausdok]

OK Matthew,

You're going to have to teach me how to determine that those are 90+ condensing units from that photo, 'cuz I'll be hornswoggled if I can tell. (Hah, bet you guys didn't know I was old enough to have ever heard that one, didja?).

OT - OF!!!

M.

[Mogollon]

Could be too low of a temperature rise across the heat exchanger of the furnace or the water heater set at a low temp with a high flow.