Inspector’s Photo Album

Issues that are easy to relate in photos

Often when a furnace or boiler has been  removed from a previously shared masonry chimney, the remaining water heater will not generate enough BTUs to maintain a flue temperature above the dew point of the flue gases, and excess condensation will develop. This condensation will prematurely rust out the vent connector and will hasten the deterioration of the chimney. The chimneys in many of these installations are old to begin with. A chimney like the one above, if it is going to continue to be in service, should be relined to be properly sized for the current equipment. Exterior
chimneys will naturally be colder and will condense more than interior chimneys.

Photo: Ceiling damage at a bathroom exhaust fan

Another solution is to upgrade to modern equipment that vents through the sidewall of the house. The chimney can then be abandoned.

Photo: A “stand-alone” water heater. Note the deterioration of the chimney and vent connector.

Photo: The defective condition that caused the ceiling damage above.

The long uninsulated bathroom exhaust fan duct in this attic will condense gallons of water during the colder seasons in our area. This condensation will make the flexible duct sag and a water trap will develop, stopping the exhaust air flow. Often this water will flow back and damage the ceiling, as in the case above.

The second defect in this installation is that the duct discharges its water-laden air into the attic, rather than directly to the exterior. This condition will cause excess condensation and resultant mildew growth in many attics as well as heating the attic and contributing to ice dams.

Reprinted with permission from the Central New York ASHI® OBSERVER, the official publication of the Central New York Chapter and its editor ASHI Member Gregg Harwood.