The condensing gas furnace represents a big step forward in heating performance and efficiency. The technology incorporated in condensing furnaces recovers heat energy normally lost in hot combustion gases exhausted up the furnace vent. These units break through the 80 percent AFUE (annual fuel utilization efficiency) ceiling and offer efficiencies of at least 90 percent. However, the advanced technology that delivers the increased efficiency and heating performance of condensing furnaces is highly dependent on a competent, skilled installation. Here are some basic tenets of a professional condensing gas furnace installation:
Proper sizing. Before the furnace is installed, a professional heating load calculation should be performed to ensure the BTU output of the unit matches the heating requirements of the home. An HVAC professional will use Manual J, the select industry load calculation software, to enter data relating to the home’s specific thermal characteristics. An accurate load calculation avoids the efficiency and comfort shortfalls that result from an oversized or undersized furnace.
Venting. Unlike conventional furnaces that exhaust hot combustion gases upward through a metal vent, condensing furnaces release cooled gases through a pipe normally routed horizontally through an exterior wall to the outdoors. The exhaust pipe must slope slightly backward toward the furnace to collect condensation and be adequately supported to prevent sagging over time. Also, the exhaust pipe and combustion air intake pipe should terminate outdoors next to each other to ensure even wind pressure in both pipes.
Condensate draining. The line that drains condensate produced by the furnace should be slightly sloped toward the drain to ensure gravity flow. Where the home’s configuration doesn’t allow this, a condensate pump must be installed.
Ductwork condition. Pressure tests the ductwork to quantify the percent of leakage relative to total airflow before concluding installation. If it exceeds recommended maximums, pinpoint the location of leaks and seal.
Since 2000, Pipe Works Services has been the choice of northern New Jersey homeowners for heating, cooling, and plumbing services. Contact us for more information about professional installation services for a condensing gas furnace.