Furnace Sidewall Venting: Here’s How To Promote Safety With High-Efficiency Systems

The most efficient furnace units available today are gas-condensing models, which can achieve efficiency ratings of 90 or above. If you decide to install this type of heating system, take extra precautions to make sure all ventilation systems are properly placed and working correctly. One of the most important safety features of gas-condensing systems is furnace sidewall venting.

Gas furnaces burn natural gas to produce heat. A by-product of this combustion process can be carbon monoxide, a very dangerous exhaust gas. In standard furnaces, all these combustion gases including carbon monoxide are usually vented through chimneys or flues.

Condensing gas furnaces achieve their high levels of efficiency by adding another step to the fuel burning and venting process. They include a second heat exchanger that reclaims additional heat from the system’s exhaust gases before they are vented away. When this happens, the exhaust gases cool and condense, creating a slightly acidic by-product.

The potential danger from the exhaust of a condensing furnace is two-fold. First, the exhaust can still contain carbon monoxide that could leak back into your home if the ventilation system is not airtight. Second, the water condensate from the additional heat extraction process can cause damage to chimneys and chimney liners if it accumulates and freezes. The acidic components can also damage unprotected bricks and mortar in a chimney. For these reasons, exhaust from a condensing furnace should never be discharged into a standard chimney.

Instead, the system should be cleared using furnace sidewall venting, which involves installing separate vent pipes horizontally through the wall of your home. These ventilation pipes can be effectively isolated from the combustion chamber and made airtightly, which reduces the possibility of gas leakage. They can be constructed so that condensate in the pipes drains backward without freezing and causing blockages in the vent system.

Do you live in Greater Cleveland or northern Ohio? If so, you can rely on P. K. Wadsworth Heating & Cooling for professional HVAC service, sales, maintenance, and repair. Contact us today for more information on high-efficiency furnaces and for expert help with furnace sidewall venting and related safety features for your high-efficiency heating system.