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WARM CHOICE Program Combustion Safety Testing Energy Essentials Core Contractor Training December 10 and 11, 2008 Four Points by Sheraton, Mars, PA A. Tamasin Sterner, Pure Energy
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Controversial and Confusing Action Levels vary BPI? DCED? Other? Terminology varies Procedures vary What do you do with unvented appliances? What do you do with coal stoves? How far should Columbia Gas go to fix problems?
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WARM CHOICE Procedure Combustion safety testing has been required as part of the WARM CHOICE program for many years. The procedure and action levels have been left up to the WARM CHOICE contractor and Columbia Gas Technicians.
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Why Test? When air sealing or insulation is installed in a home with fossil fuel heating or water heating systems, the air exchange across the thermal boundary will (should) be reduced as part of the WARM CHOICE installed measures. Any planned reduction in air flow (CFM -50Pa) means the combustion appliances must be checked BEFORE air sealing to be sure they are operating safely…. And they need to be checked AFTER air sealing to be sure they still operate safely.
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Because… Air is needed for proper combustion. When air flow is restricted, combustion appliances can be starved for air. If a combustion appliance is starved for air, it won’t burn properly and/or it pulls its combustion air down the flue and back-drafts. Back-drafting (spillage) is dangerous because the flue gasses contain CO and other bad things. We want to be sure the appliances operate safely.
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Combustion Testing Procedures Follow the DCED Weatherization Standards and Field Guide for combustion safety testing procedures and action levels.
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Which WARM CHOICE Customers Get Combustion Testing? Typical jobs: Any job receiving air sealing or insulation that has conventionally vented combustion appliances and/or a gas range
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Combustion Testing Includes: CO testing: ambient air, combustion appliance zone (CAZ), flues Gas leak detection Spillage and flame roll-out evaluation CAZ depressurization Draft evaluation Gas range testing
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Combustion Safety Testing Audit Documentation Combustion Safety Tests must be performed if: Conventionally vented combustion appliances exist and Air sealing is done – to reduce cooling load or to reduce heating load
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Sample Audit Form Page
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The Big Picture Why Perform Combustion Safety Tests? When inadequate oxygen is present, in addition to CO2 being formed, Carbon Monoxide (CO) can be formed. This is our main concern. Carbon rich fuels, like Fuel Oils, can also lead to Carbon Particles, or Smoke, being produced.
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Combustion Diagram The ideal operating range is a setting with excess air. IncompleteComplete Excess Fuel Excess Air Flue gas components Ideal operating range ofburners CO 2 O 2 Eff. Stoichiometric line Courtesy of Bill Spohn, Testo
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Air Tight Building Negative pressure conditions in homes can create back-drafting of combustion appliances Common exhaust equipment (i.e. attic fan, bathroom exhaust, fireplace) can compete with the normal venting process of combustion appliances Graphics © COAD 1996 Courtesy of Bill Spohn, Testo
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Sometimes Things Go Backwards Back-Draft Flame Roll-Out Spillage Graphic © Readers Digest 2001 Courtesy of Bill Spohn, Testo
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Combustion Testing Video 16 minute video demonstrating the combustion safety testing procedure
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What is flue gas? carbon hydrogen sulfur oxygen nitrogen water Oxygen(20.9%) water vapor Nitrogen (79%) Carbon dioxide CO 2 Carbon monoxide CO Sulfur dioxide SO 2 O 2 - balance Nitrogen oxide NO x Water vapor H 2 O Smoke (oil systems) fuel-residual ashes fuel air How is it formed? Courtesy of Bill Spohn, Testo
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What is Carbon Monoxide ? CO originates from incompletely (oxidized) burnt carbon (fuel). It is very dangerous for human and animals, because it prevents the absorbstion of oxygen in the blood stream. Reasons for the formation: - fuel rich mixture - Improper venting - too early cooling of the flame (1128 F) CO is expressed in parts per million (ppm). Courtesy of Bill Spohn, Testo
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CO Sources Fuel burning furnaces and hot water heaters Fuel burning boilers Fuel burning space heaters Kitchen ranges & ovens Auto emissions –Attached garages Fireplaces Tobacco smoke Courtesy of Bill Spohn, Testo
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Characteristics of CO Odorless Colorless Tasteless Mixes well in air –Does not stratify –Follows air flow in a structure Poisonous Courtesy of Bill Spohn, Testo
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CO Health Effects 35 ppm NIOSH Permissible Exposure Limit – 8 hours 200 ppmNIOSH Ceiling– 15 minutes 200 ppmSlight headache with 2-3 hours 400 ppmHeadache within 1-2 hours 800 ppmSickness & twitching of limbs within 1- 2 hours; unconsciousness in 2 hours 1,600 ppmHeadache within 20 minutes; death within 2 hours 3,200 ppmDeath in 30 minutes 6,400 ppmDeath in 10-15 minutes 12,800 ppmDeath in 1-3 minutes Courtesy of Bill Spohn, Testo
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CO Testing Fuel Burning Appliances Sample from entry of home to exit of home Sample around all un-vented appliances Sample before draft diverter of atmospheric devices Sample where you may suspect CO Graphics © COAD 1996 Courtesy of Bill Spohn, Testo
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Types of Furnaces Atmospheric – Natural Draft –Buoyancy Creates NEGATIVE Pressure in Flue Induced Draft –Fan Creates NEGATIVE Pressure in Flue Power Draft –Power Vent –Fan Creates POSITIVE Pressure in Flue Condensing –Sealed combustion
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Calculating Combustion Efficiency Natural Gas Light Oil Heavy Oil Propane Wood Ambient Temp (combustion air) Oxygen O 2 StackTemp fuel Air Temp The analyzer uses the oxygen and net temperature measurements in fuel specific equations to give the efficiency, CO2 and excess air readings. Courtesy of Bill Spohn, Testo
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Combustible Gas Leak Detection
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Spillage, Flame Roll-Out, Backdrafting
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Testing for CO in the Appliance Test undiluted CO
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Testing Draft Notice the hole in the boiler flue pipe
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Testing Draft Some combustion analyzers test for pressure as well as CO. This one records pressure (draft) in Inches of Water Column, IWC
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Testing Condensing Furnaces Test under Steady State Operating Conditions Sample around burner (CO) Sample efficiency in plastic vent pipe (MFG or authority) Or sample in stack termination (CO) Follow Manufacturer’s Specs Graphics © COAD 1996 Courtesy of Bill Spohn, Testo
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Venting Types Video 17 minute Gas Venting video
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Gas Appliance Categories Cat. I fan-assisted gas appliance: negative pressure, a high vent temperature avoiding condensation and an integral fan drawing combustion air through chamber Cat. I gas appliance: negative pressure, a high vent temperature, Cat. II gas appliance: –negative pressure, low vent temperature causing excessive condensation Cat. III gas appliance: –positive vent pressure in the vent, a high vent temperature Cat. IV gas appliance: - positive vent pressure in the vent low vent temperature causing excessive condensation Courtesy of Bill Spohn, Testo
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Unvented Appliances – Test Air- Free or Undiluted Gas Ranges –CO Hot-Pot www.karg.com Gas Ovens Test CO Air free, undiluted Courtesy of Bill Spohn, Testo
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Range Top and Oven CO Testing
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Sealing Test Holes For double wall (B-vent) flue pipes, letters from vent manufacturers say to use “high temperature, non- hardening sealant to plug the hole on the inner sleeve. Do the same for the outer sleeve, but cover with a patch of aluminum tape over the sealant”. For single wall flue pipes, use the same, or metal plugs.
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What If A Test Fails? If a test fails before air sealing and/or insulating: follow procedure – no air sealing until the problem is fixed If a test fails after air sealing and/or insulating: follow procedure – fix the problem
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Weatherization Release WARM CHOICE participants agree not to use any unvented combustion appliances. This must be signed on every job Homes with unvented combustion heating appliances will NOT be insulated or air sealed. These appliances can be removed.
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Emergency Procedure If the testing fails, follow the procedure. This may include: –Shutting down the appliance –Calling Columbia Gas or the HVAC contractor for service –HVAC or water heater replacement –No work being done until the problem is remedied.
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What Information is Important? Combustion Efficiency –02, Temperature, Fuel Reduce Fuel Cost - Savings To determine Operating Condition Diluting effects of excess air (NO, NO2, SO2, CO) Weight of pollutant (lbs/Mbtu) Carbon Dioxide (CO 2 ) O 2 Reference (3%, air free) Emission Conversions Excess Air Extra Air for Combustion Courtesy of Bill Spohn, Testo
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Bonus Video 6 minute Efficiency Video
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Typical Readings Gas Fired Power Burners –Oxygen : 3 % - 6 % –Carbon Dioxide:8.5 % - 11 % –Stack Temp : 275 ºF to 570 ºF –Draft: -.02WC to -.04WC in the Stack –Carbon Monoxide:<100 ppm (diluted) –Always Follow Mfr‘s Specifications Courtesy of Bill Spohn, Testo
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Typical Readings Oil Fired Power Burners –Oxygen (cast iron cone): 4% - 7 % –Oyygen (flame retention): 3%-6% –Carbon Dioxide10 – 12.5% –Stack Temp (60-79 AFUE): 400 ºF to 600 ºF –Stack Temp (80 plus AFUE): 330 ºF to 450 ºF –Stack Temp (90 plus AFUE): Less than 125ºF –Draft: -.02WC Overfire –Carbon Monoxide:< 50 ppm (diluted) –Always Follow Mfr‘s Specifications Courtesy of Bill Spohn, Testo
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