1 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Combustion Appliances WEATHERIZATION ENERGY AUDITOR SINGLE FAMILY WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010

2 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Learning Objectives By attending this session, participants will: Understand the basic principles of combustion, distribution and venting and be able to recognize safety-related problems. Understand the health and safety issues related to combustion equipment. Know the basics of visual and diagnostic combustion appliance safety and efficiency inspection. Know the test procedures for vented and non-vented appliances. Understand the relationship between combustion safety problems and poorly designed or non code-compliant vent systems. Understand worst case Combustion Appliance Zone (CAZ) Testing.

3 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES We test to assure: Health and safety. Building integrity. Comfort. Energy efficiency. Why Test Combustion Appliances? Photo courtesy of New River Center for Energy Research and Training (NRCERT)

4 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Combustion Basics COMBUSTION APPLIANCES

5 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov The Combustion Triangle Requirements for Combustion (burning): COMBUSTION APPLIANCES

6 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Complete Combustion Results in: Triangle of Combustion Products

7 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Complete Combustion Occurs…. When all the fuel is burned with sufficient oxygen to produce carbon dioxide and water vapor. Complete Combustion Photo Courtesy of NRCERT Combustion by-products

8 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES CO Occurs When: The ratio of fuel to oxygen is either too high to permit the complete formation of CO 2 or The temperature is too low to permit complete burning to occur. Caused by: Too much fuel for the amount of oxygen. Not enough oxygen for the amount of fuel. Not enough heat (flame impingement). Carbon Monoxide from Incomplete Combustion

9 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Combustion, Distribution & Venting Return Air Main Burner Supply Air Vent Combustion Gases Dilution Air Heat Exchanger Gas Valve Combustion Air

10 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES What do we inspect on combustion appliances? Chimney safety. Vent pipes. Wiring. Heat exchanger. Distribution systems. Combustion air. What to Inspect - Visual Photo courtesy of PA Weatherization Training Center

11 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Fuel Leak Testing #1 Use a calibrated gas leak detector to locate fuel leaks. Photo Courtesy of NRCERT Bacharach

12 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Fuel Leak Testing #2 Test all joints, valves and fittings. Use soap bubbles to confirm a leak. Photos Courtesy of NRCERT COMBUSTION APPLIANCES

13 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Fuel Leak Testing #3 Gas leak detector for gas and propane. Visual inspection and the personal sniff test for fuel oil. Photos Courtesy of NRCERT

14 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Photos Courtesy of NRCERT Is insulation on wiring missing or deteriorated? Is the heating system on its own circuit? Are wires properly clamped, connected and enclosed? Inspection – Wiring

15 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Clearance to Combustibles Oil and WoodGas Single wall 18”Single Wall 6” Double Wall Super Six, Dura Vent 6” Double Wall B-Vent or B-W Vent 1” Manufactured Chimney 2” or Per Manufacturer Instructions Photo Courtesy of NRCERT COMBUSTION APPLIANCES

16 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES NFPA-54 states that combustion air must be provided for any combustion zone where the collective fuel input exceeds 1,000 Btu per 50 cubic ft. Make-up air can be provided from outdoors or from other zones of the building. Combustion Air Photo Courtesy of NRCERT

17 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Change out the furnace filter and educate the client about checking it periodically. Filter Replacement Photo Courtesy of NRCERTPhoto Courtesy of PA Weatherization Training Center COMBUSTION APPLIANCES

18 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Blower Maintenance Clean the blower. Photo Courtesy of NRCERT Photo Courtesy of PA Weatherization Training Center COMBUSTION APPLIANCES

19 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Rust on the draft hood of a natural gas furnace is evidence of severe spillage of flue gases. Soot stains at the inspection port of an oil fired boiler indicate the need for a tune up. Combustion Safety Problems Photos Courtesy of PA Weatherization Training Center COMBUSTION APPLIANCES

20 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES What do we test on combustion appliances? Fuel leaks. Fuel input rate. Sufficient combustion air. Worst case draft. Carbon monoxide. Combustion efficiency. What to Test – Diagnostics Photo Courtesy of NRCERT

21 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Combustion Analyzer Bacharach, Combustion analyzers should be able to measure: Flue gas oxygen content. Flue gas temperature. Ambient temperature. Flue gas carbon monoxide. Combustion efficiency. Flue gas carbon dioxide content. Flue Gas air-free or as measured CO content. Testing Equipment - Criteria COMBUSTION APPLIANCES

22 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Draft Gauge Smoke Tester (for Oil) Selected Testing Equipment Inspection Mirror Digital Probe Thermometer COMBUSTION APPLIANCES

23 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov If you’re not testing, you're guessing! Testing Equipment Photo Courtesy of NRCERT COMBUSTION APPLIANCES

24 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Unvented Space Heaters Unvented space heaters release all of their combustion byproducts into the home. In addition to carbon dioxide and water vapor, compounds of carbon monoxide, excess air, and sulfur dioxide will be present. Photos Courtesy of NRCERT COMBUSTION APPLIANCES

25 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Visual Assessment – Space Heaters WPN 08-4: Space Heater Policy No Wx work allowed where unvented gas or liquid fuel space heater is primary heat source. Strongly encourages removal and replacement of such heaters with vented, code-compliant heating systems prior to weatherization. Input rating at or below 40,000 BTU/hr. MVR guidelines apply. WAP funds may only replace primary heating system, e.g. unvented with vented, code- compliant system. May not replace unvented space heaters left in home as secondary units with code-compliant unvented units. Mobile home: must be vented outside. Photo Courtesy of NRCERT COMBUSTION APPLIANCES

26 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Why Test Gas Cook Stoves? Elevated Levels of CO are Common. People often use them as a heat source. CO Kills. Knowledge implies action. Cook Stove Testing Photo Courtesy of NRCERT

27 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Gas Cook Stove Testing - Stove Top Test each range top burner for CO. Hold probe 6” above flame and measure the CO content in ambient air. A portable flue section concentrates combustion byproducts for an accurate CO measurement. Photos Courtesy of NRCERT

28 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Gas Cook Stove Testing - Oven Insert the probe of the analyzer into the oven vent and read the CO content after the oven has warmed. Prepare the oven for a test by removing stored items, aluminum foil, etc. Photos Courtesy of NRCERT

29 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Furnace Testing Protocol Furnaces must be tested to assess: Safety (fuel leaks, clearances, etc.). Flue gas temperatures. Oxygen (O 2 ) or Carbon Dioxide (CO 2 ). Carbon Monoxide (CO) levels. Draft. Condition of the heat exchanger. Photos Courtesy of PA Weatherization Training Center Open ended duct Single wall flue for oil heat. COMBUSTION APPLIANCES

30 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Furnace Testing Methods - Visual Check for: Dirt and debris. Burner alignment. Soot, evidence of flame roll-out. Heat-exchanger condition. Vent pipe and roof termination. Gas or oil leaks. Wiring condition. Condition of air filter. Cracked Heat Exchanger COMBUSTION APPLIANCES Photo Courtesy of NRCERT

31 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Heat Exchanger Leakage Testing Test Methods: Look for flame damaged areas on the heat exchanger. Look for rust on the burner ports. Measure flue gas concentration before and after blower starts. There should be no more than 1% oxygen change when the blower starts. Observe change in draft, CO or flame when blower turns on. Look for flame damaged areas on the heat exchanger. Photo Courtesy of NRCERT Damaged area of heat exchanger COMBUSTION APPLIANCES

32 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Use a strong light and an inspection mirror. Is the heat exchanger rusty? Are there cracks? Inspection – Heat Exchanger

33 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Find the worst case depressurization in the CAZ. Under worst case conditions conduct: -Spillage Test -Draft Test -CO Test Perform at the time of the audit and at the end of each work day. Deactivate appliances until hazard is fixed Worst Case Combustion Safety Testing Conduct these tests for vented systems only!

34 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Record outdoor temperature. Clean dryer lint filter and furnace filter. Deactivate all combustion appliances. Close all exterior doors and windows. Open interior doors containing exhaust fans. Close all other interior doors. Setting Up Worst Case Conditions

35 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Record the pressure difference of the CAZ with respect to outdoors using a manometer. Operate all exhaust devices. Record the pressure difference of the CAZ with respect to outdoors. Conduct CO, spillage, and draft tests under worst case conditions. Open and close interior doors (including door to CAZ). Repeat for all other vented appliances. Return dwelling, exhaust fans, and combustion appliances to normal settings. Conducting a Worst Case Test

36 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Test for Spillage Photo Courtesy of PA Weatherization Training Center No spillage after 1 minute of operation. Smoke stick at draft diverter. COMBUSTION APPLIANCES

37 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Spillage –Test at vent openings, i.e. dilution air openings, barometric damper, with smoke. Draft –Test in vent connection between last opening in vent connect and chimney. –Oil burners – Test over fire in combustion chamber. CO –Test at appliance breech, between appliance and first opening in vent connect or directly above heat exchanger. –Condensing gas appliances – Test at vent termination. Spillage, Draft and CO

38 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Atmospheric Furnace CO, Draft and Steady State Efficiency 80+ Induced Draft Furnace Figures courtesy of Corporation for Ohio Appalachian Development (COAD) Draft CO CO & Draft COMBUSTION APPLIANCES

39 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov 90+ Condensing Furnace CO and Draft Test Locations #1 Floor Furnace Figures courtesy of COAD Draft CO CO & Draft COMBUSTION APPLIANCES

40 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov CO and Draft Test Locations #2 Fuel Oil FurnaceBarometric Damper Figure courtesy of COAD Draft CO Photo courtesy of NRCERT COMBUSTION APPLIANCES

41 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Outdoor Temperature Appliance < 20 °F21-40 °F41-60 °F61-80 °F> 80 °F Gas fired furnace, boiler or water heater with atmospheric draft -5 Pa IWC -4 Pa IWC -3 Pa IWC -2 Pa IWC -1 Pa IWC Oil fired furnace, boiler or water heater with atmospheric draft -15 Pa IWC -13 Pa IWC -11 Pa IWC -9Pa IWC -7 Pa IWC Minimum Acceptable Draft COMBUSTION APPLIANCES

42 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov APPLIANCESuggested CO Action Levels Gas furnace, boiler, or water heater100 ppm, as measured Unvented gas space heater200 ppm, air free Oil-fired furnace, boiler, or water heater100 ppm, as measured Gas cook stove: Range-top burner25 ppm, as measured Gas cook stove: Oven100 ppm, as measured Carbon Monoxide Action Levels COMBUSTION APPLIANCES

43 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Solve excessive depressurization or inadequate draft: Repair chimney obstructions, disconnections, or leaks. Properly size the vent, connector, or liner. Install a metal chimney liner and/or a wind-rated chimney cap. Seal leaks in the return ducts of the CAZ. Balance supply and return air by adding new returns, or by adding passive return air openings to the main body of the house. Reduce capacity of large exhaust fans. Provide make-up air for dryers and exhaust fans. Provide combustion air inlet to CAZ. Combustion Safety Problems - Fixes

44 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Open Returns Photo Courtesy of PA Weatherization Training Center Open Return Disconnected Draft Hood COMBUSTION APPLIANCES

45 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Measuring BTU Input Turn on only the unit to be measured. Others should be off. Time one revolution of smallest dial, and compare to a calibration chart. Any discrepancy with the rated input should be within 10% of the input rating. Clocking the Gas Meter Photo courtesy of NRCERT Time one revolution of smallest dial COMBUSTION APPLIANCES

46 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov What’s Wrong with this Picture? Photo Courtesy of PA Weatherization Training Center From Furnace From Hot Water Tank To Chimney COMBUSTION APPLIANCES

47 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Chimney and Vent Connectors Chimney Combustion gases mixed with room air Vent Gas Heating Appliance Draft Hood Water Heater Draft Diverter Dilution Air

48 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES A Venting System should: Carry all combustion byproducts to outdoors. Establish draft quickly. Be properly sized with minimal restrictions. Have long durability (corrosion resistance). Not overheat surrounding materials. Have adequate make up air. Venting Systems

49 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Chimneys and Vents Photo Courtesy of PA Weatherization Training Center From Hot Water Tank Chimney Single Wall Vent From Furnace

50 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Masonry chimneys. Type B vents – double wall, round. Type B-W vents – double wall, oval. Type L vents – more heat, corrosion resistant. Single wall metal – interior only. Plastic pipe vents – low temp condensing furnaces. Vent Types Photo courtesy of NRCERT Masonry Chimney and B-Vent

51 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Vent gas temperature. Heat loss from the vent. Height of the venting system. Capacity of the venting system. Restrictions in the venting system. Ambient temperature. Negative pressure in the CAZ. Factors That Affect Vent Operation See a problem here?

52 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Chimney Specifications Masonry chimney is too short. Photo Courtesy of PA Weatherization Training Center

53 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Chimneys and vents should: Be connected and unblocked. Not have holes in the chimney or vent. Have a sound liner. Rise no less than 1/4” per linear foot in the direction of the outlet. Extend at least 3’ above the highest point at which they pass through the roof. Be the appropriate type and size for the combustion appliances. Be at least the same diameter as the exhaust port of the combustion appliance. Chimneys and Vents #1

54 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Chimneys and Vents #2 Chimneys and vents must not be blocked and must have no holes in the chimney or vent. Missing cleanout Blocked chimney Photos Courtesy of PA Weatherization Training Center COMBUSTION APPLIANCES

55 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Hole in Vent ConnectorImproper Slope Chimneys and Vents #3 Hole in vent connector. Photos Courtesy of PA Weatherization Training Center Improper slope. COMBUSTION APPLIANCES

56 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov No Vent Connector.Reduced vent connector out of compliance with code. Chimneys and Vents #4 Reduced vent connector. Photos Courtesy of PA Weatherization Training Center No vent connector. COMBUSTION APPLIANCES

57 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Water Heaters Burn marks above the burner compartment are evidence of flame roll out. Spillage of flue gases or insufficient draft is often a result of an improper installation such as this. Photos Courtesy of PA Weatherization Training Center Photos Courtesy of NRCERT COMBUSTION APPLIANCES

58 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Testing Water Heaters #1 Atmospheric Hot Water Tank Test for draft above the draft diverter. Figure courtesy of COAD Test for CO on both sides of the baffle Photo courtesy of NRCERT COMBUSTION APPLIANCES

59 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Test for CO directly into the breech of the unit on both sides of the baffle that runs up through the center of the tank. On start up, time the amount of spillage. Then test draft above the draft diverter. Spillage should not exceed 1 minute. Testing Water Heaters #2 Photos courtesy of NRCERT Draft diverter COMBUSTION APPLIANCES

60 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov Photos courtesy of NRCERT Chimney Liner COMBUSTION APPLIANCES

61 | WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM – August 2010eere.energy.gov COMBUSTION APPLIANCES Understanding the basic principles of combustion, distribution, and venting will enable the auditor to recognize safety problems. Health and safety issues related to combustion equipment are some of the most important aspects of auditing a home. Visual and diagnostic combustion appliance safety and efficiency inspections, and worst case CAZ testing reveal potentially dangerous situations and guide retrofit strategies. Practice appropriate test procedures for vented and non- vented appliances. Understanding the relationship between combustion safety problems and poorly designed or non-compliant vent systems is important to finding solutions. Summary