High Efficiency Furnace Venting Freezing At Roof Vent

If your furnace has an afue rating below 90 percent it will most likely have a flue pipe that goes up through your roof.

High efficiency furnace venting freezing at roof vent.

There is a disconnection at the elbow. The gas vent pipe from the water heater tank is improperly sloped. As the gases are cooler pvc cpvc or abs piping can be used to carry the exhaust to the outside. This residual liquid is highly acidic.

A high efficiency condensing furnace can achieve efficiency ratings of 90 or above. This condensing process along with the one that occurs within the high efficiency furnace itself creates moisture that can collect and freeze around and inside exhaust pipes since it can t travel far enough away from the home before condensing. That depends on whether you have a standard efficiency or a high efficiency furnace. It s a high efficiency gas furnace and that s the exhaust vent.

That s because the combustion byproducts are in a gaseous form so the gases can float up through the flue pipe and out of your roof. This combination of carbon dioxide and water would damage the type of vents used in conventional systems which run vertically out of a home. Once a high efficiency condensing furnace removes this excess heat that conventional furnaces vent to the outside of a home the leftover mixture is acidic water. This vent pipe is connected to the shared vent stack with the furnace.

If your furnace has an afue rating of 90 percent or above it will have a flue pipe that goes out of the side of your house. Due to the condensing nature of a high efficiency furnace its venting must be made of a material that is resistant to corrosion. What is vented is a residual corrosive condensate of water and carbon dioxide. Many municipalities do not allow metal foil tape either.

Since it takes less energy to move the cooled exhaust horizontally he furnaces typically exhaust to the side of a building rather than the top. In a great majority of cases plastic piping is used to vent high efficiency equipment.