Transcription
WELCOME
Condensing vs. Non-CondensingGas Appliances
Gas Non-Condensing Furnace Burners are ignited Blower motor is turned on Cool or return air enters, isfiltered and blown throughfurnace heat exchanger Heat from the combustionchamber goes through theheat exchanger Air absorbs heat and is passedout through supply duct Exhaust gasses are vented outthrough type B vent to roof
Non-CondensingFurnace Installation Requires type B metal vent up to and throughthe roof Requires indoor combustion air Should have minimal professional maintenance Minimum 80% efficient
Gas Condensing Furnace Second heat exchanger used to heatthe air from condensed exhaust gasses Less expensive venting (Usually PVC) onnew construction
Condensing Furnace Installation Requires PVC venting Will not connect to existing venting whenreplacing existing furnace Most models are direct vent (does not requireindoor combustion air) Can require annual professional maintenance Minimum 90% efficient
OrphanedWater Heater Many homes utilize a combination venting system through a chimney where theWH & Furnace share a vent. In existing homes where an older non-condensing Furnace is replaced by a 90 efficiency appliance, an “Orphaned Water Heater” can occur. When the new condensing furnace is vented directly outside, the remaining ventfor the WH is drastically oversized and serious CO concerns may arise. Methods to address this problem can be a major financial constraint.
Orphaned Water HeaterConnected to oversized flueLiner installed through flue
Gas Non-Condensing Water Heaters Cold water enters through theinlet and is released at thebottom The gas burner heats thewater Warm water rises and exitsthrough the outlet pipe Exhaust from burner exitsthrough a baffled flue and isvented outside (type B vent)
Standard Storage-TypeWater Heater Installation Requires 6” of clearance for type B ventilation 4 - 6 sq ft ground space Requires indoor combustion air Seamless installation when replacing existingwater heater (reconnect to existing structures) Should be flushed by homeowner annually Requires very little other maintenance
Gas Condensing Water Heater Hot exhaust gases are captured andutilized to heat the water in additionto main burner Less expensive venting in newconstruction Cannot connect to existing ventingwhen replacing old WH More Efficient Low NOx (Nitrogen Oxides) Emission
Condensing Water Heater Installation Requires PVC venting, no clearance to combustibles(some models may be direct vent) 4 - 6 sq ft ground space Requires new venting when replacing existing waterheater May not require indoor combustion air Annual professional maintenance recommended
MID-EFFICIENCYAFUE(Annual FuelUtilizationEfficiency)VENTING Traditional metallic pipingand/or chimney liner80-83MidEfficiency Utilize existing venting onremodel/upgrade Fan-assisted draft Should be through roof Must be vented accordingto manufacturer’sinstructions.90 Most likely require PVCHighEfficiency Can be direct-vent or fanassisted draft Can be through wallVS. HIGH-EFFICIENCYBASIC OPERATIONENHANCEMENTS Electronic IgnitionPROSCONS Retrofits are simple Cannot be direct vent Fan induced Draft Less expensive Consume more fuel Small Diameter Flue Several fan/burnercontrols Less maintenance Proven/familiardesigns More expensive Sealed Combustionchamber Utilize second heatexchanger to extractheat from flue gas More maintenance Consume less fuel Produce lessunwanted byproducts Lower temp flue gas Condensing Many fan/burnercontrols Produce morebyproducts Easier install on newconstruction Newer designs notas well proven More parts to break Condensate disposal Retrofits are complex Orphaned WH
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Orphaned Water Heater Many homes utilize a combination venting system through a chimney where the WH & Furnace share a vent. In existing homes where an older non-condensing Furnace is replaced by a 90 efficiency appliance, an "Orphaned Water Heater" can occur.
