I seem to have condensation buildup on the inside of a dual-walled horizontal flue pipe coming from heater
graef
| Posted in Mechanicals on
There is a hole on vertical portion of same flue pipe, although single wall at this point. Would this hole cause moisture buildup on inside of duct and the water would accumulate in low portion of the duct and leak out?
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Graef,
It sounds as if you are describing a flue, not a duct. A flue carries combustion gases (what we used to call "smoke") away from an appliance that burns natural gas, propane, fuel oil, or firewood.
The likelihood of condensation in a flue varies depending on the type of appliance we are talking about. If we're talking about a furnace, for example, there is a type of furnace called a condensing furnace -- an appliance where moisture in the flue gases should condense inside the appliance before the gases are sent to the flue. (This type of appliance is usually power-vented -- there is a fan that pushes the combustion gases through the flue.)
A non-condensing furnace may or may not be power-vented, but this type of furnace doesn't have any condensation if it's working properly.
In all cases, you usually don't want condensation in the flue -- although in some cases, flues are designed to handle incidental condensation. (This type of flue is usually PVC, and is installed with a slight slope.)
To guide you on the next step, you need to describe the type of appliance you are talking about.
That said, our advice is likely to be the same not matter what type of appliance you have: Call a trained service person to come to your house and fix the problem. You don't want to mess around with combustion safety, since poorly functioning combustion equipment can be dangerous. If your appliance has a venting problem, there may be a carbon monoxide risk.
Hi, thanks for response. It's a Bryant plus 80 forced air furnace. I
Some other possible sources of flue moisture: condensation of ex-filtrating interior air and rain.
Ex filtrating interior air?
Graef,
I can't tell from your description whether this is a condensing furnace or non-condensing furnace. In any case, get a service tech there as soon as possible.
One category of Bryant furnaces has installation instructions with this note: "Category I furnaces must be vented vertically or nearly vertically unless equipped with a listed power ventor." I have no idea whether this applies to your furnace.