# WELCOME

# Condensing vs. Non -Condensing



# Gas Appliances

# Gas Non - Condensing Furnace

• Burners are ignited • Blower motor is turned on • Cool or return air enters, is filtered and blown through furnace heat exchanger • Heat from the combustion chamber goes through the heat exchanger •Air absorbs heat and is passed out through supply duct • Exhaust gasses are vented out through type B vent to roof

# Non -Condensing



# Furnace Installation • Requires type B metal vent up to and through 

## the roof • Requires indoor combustion air • Should have minimal professional maintenance • Minimum 80% efficient

# Gas Condensing Furnace

• Second heat exchanger used to heat the air from condensed exhaust gasses • Less expensive venting (Usually PVC) on new construction

# Condensing Furnace Installation • Requires PVC venting • Will not connect to existing venting when replacing existing furnace • Most models are direct vent (does not require 

## indoor combustion air) • Can require annual professional maintenance 

## • Minimum 90% efficient

# 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. • When the new condensing furnace is vented directly outside, the remaining vent for the WH is drastically oversized and serious CO concerns may arise. • Methods to address this problem can be a major financial constraint.

# Orphaned Water Heater Connected to oversized flue Liner installed through flue

# Gas Non - Condensing Water Heaters

• Cold water enters through the inlet and is released at the 

### bottom •The gas burner heats the water 

### •Warm water rises and exits through the outlet pipe • Exhaust from burner exits 

### through a baffled flue and is vented outside (type B vent)

# Standard Storage-Type 

# Water Heater Installation • Requires 6” of clearance for type B ventilation • 4 - 6 sq ft ground space • Requires indoor combustion air • Seamless installation when replacing existing water 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 and utilized to heat the water in addition to main burner 

## • Less expensive venting in new construction 

## • Cannot connect to existing venting when 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 water heater • May not require indoor combustion air • Annual professional maintenance recommended

# MID- EFFICIENCY VS. HIGH - EFFICIENCY AFUE (Annual Fuel Utilization Efficiency) VENTING BASIC OPERATION ENHANCEMENTS PROS CONS 80-83 Mid Efficiency • Traditional metallic piping

and/or chimney liner • Utilize existing venting on remodel/upgrade • Fan - assisted draft • Should be through roof • Electronic Ignition • Fan induced Draft • Small Diameter Flue • Several fan/burner controls • Retrofits are simple

• Less expensive • Less maintenance • Proven/familiar designs • Cannot be direct vent • Consume more fuel • Produce more byproducts

90+ High Efficiency • Must be vented according

to manufacturer’s instructions. • Most likely require PVC • Can be direct-vent or fan assisted draft • Can be through wall • Sealed Combustion chamber • Utilize second heat exchanger to extract heat from flue gas • Lower temp flue gas • Condensing • Many fan/burner controls • Consume less fuel • Produce less unwanted byproducts • Easier install on new construction • More expensive • More maintenance • Newer designs not as well proven • More parts to break • Condensate disposal • Retrofits are complex • Orphaned WH

# THANK YOU