Flue Pipes & Chimney Liners

Why Some HVAC Systems and Water Heaters Use Flue Pipes and Chimney Liners

Heating systems that use gas- or oil-fired furnaces or boilers are usually equipped with flues to vent harmful fuel combustion gasses out of the building safely as they exit the system. Gas and oil water heating systems are also connected to the chimney.

Why do some heating systems use flue pipes and chimney liners?

Heating systems that use natural gas or propane typically have flues for venting harmful gases out of the building. Gas and oil water heater are also connected to flues.

Chimney liners provide added insulation so that exhaust gases don’t condense.

Flue pipes begin where the combustion gases exit from the inducer motor housing, which is usually the connection to the boiler. A gas or oil heater has a flue pipe connected to its top. The exhaust inside a chimney must remain warm while traveling through the interior of the house so that the gas does not condense into a corrosive liquid and fall back into your furnace.

Some systems are located so close to the roof or the walls they penetrate that they don’t need chimneys to prevent condensate from forming inside them. Flues are usually connected to heating equipment installed at the bottom of a house or building. But the exhaust is vented from the top of the property. Similarly, some flues are long enough that even indoor temperatures are cool enough to cause the flue gases to condense if not insulated by a flue pipe.

Flue caps prevent water from going back down into the chimneys or flue pipes.

Chimneys are usually built with chimney linings inside them to insulate against cold ambient air temperatures and wind speeds that would otherwise cool the flue pipes and allow the gases to collect. Chimney liners help with airflow and ventilation of the rising gasses. Flue pipes end at the chimney liner, a part of the chimney system made up of varying forms of metal and clay that runs the length of the brick-based chimney. A chimney liner terminates with a cap on top so that water cannot enter.

When you are dealing with a flue pipe or chimney liner problem with your HVAC or Water Heating system in your home, it’s important to have a professional that can guide you through your options and provide you with the safest and most economical solution.  Call the professionals at Sweep Your Chimney DMV today so we can get the process started for you.