Combustion Safety

1. Combustion Safety

2. Health and Safety • Health and safety is always #1 • Never do anything to save energy that has a negative impact on health and safety. • All (existing and potential) health and safety issues have to be remedied prior to or in conjunction with any energy measures.

3. Combustion Appliances and Combustion Gases • Carbon Monoxide (CO) • Safety inspection • Combustion air • CO limits • Testing

4. Carbon Monoxide (CO) • Combustion appliances should not produce (much) CO. • If CO (over limits) exists, something is wrong! • CO will be present when there is incomplete combustion. • Limited combustion air. • Cooling of the flame.

5. Carbon Monoxide (CO) • At elevated levels, carbon monoxide causes headaches, fatigue, queasiness, and at very high levels, brain damage and death. YES - DEATH

6. CO Levels • 035 ppm - Headache and dizziness within six to eight hours of constant exposure • 100 ppm - Slight headache in two to three hours • 400 ppm - Frontal headache within one to two hours • 800 ppm - Dizziness, nausea, and convulsions within 45 min. Insensible within two hours. • 1,600 ppm - Headache, dizziness, and nausea within 20 min. Death in less than two hours.

7. Is There CO in the House? • When you first walk into a home, have your CO detector on, protect yourself! • Check ambient (air inside the house) levels. • All rooms/spaces that contain a combustion appliance.

8. Ambient Air Standards • Ambient air should not be above 9 parts per million (PPM). • Over 35 PPM ambient, stop testing, ventilate, evacuate the home and call the appropriate officials. • If CO fails, it must be fixed before or in conjunction with any air sealing (including duct repair) repairs.

10. Safety Inspections • Inspect gas lines, shut off valve, flex lines and check for leaks • Shut off valve must move with fingers • Flex lines prior to 1973 must be replaced • Visual flags of malfunction or disrepair • Flame rollout, Burnt wires, Matches • Bypassed safety devices • T&P valve and drain

16. Signs of flame rollout

17. Flame rollout

20. Flame rollout sensors Burners

22. T&P valve T&P drain line

24. T&P valve was capped off • Most home owners do not know • what the valve is for. • If it is leaking they will cap it.

27. Visual Inspection of Flue • Is it the right size? • Is there any signs of failure? • Signs of condensate • Rust • Blockage • Are there only two turns? • Does it meet slope requirements (code)?

33. Combustion Air • Check to ensure that combustion air standards are met. • NFPA 54, chapter 7 and 8. • For a fire to burn clean (produce CO2) it needs sufficient oxygen. • Limit oxygen, fire produces CO

34. Combustion Air • Combustion air from inside the house, there must be 50 cubic feet of interior space per 1000 Btu/hr input. • The space must be available at all times (if an area can be isolated by closing a door, it can not be counted).

35. Combustion Air • In homes that receive combustion air from outside, two openings are required. • One shall be within 12 inches of the top and one within 12 inches of the bottom of the space containing the combustion equipment. • The openings shall communicate directly, or by ducts, with the outdoors.

36. Combustion Air • Openings communicating with the outdoors with vertical ducts shall provide one square inch per 4000 Btu per hour of the total input of all gas utilization equipment in the space. • Openings communicating with the outdoors with horizontal ducts shall provide one square inch per 2000 Btu per hour of the total input of all gas utilization equipment in the space. NFPA 54, chapter 7 and 8 provide the requirements, in detail, for combustion air, chimneys, and vents.

37. Heat Exchanger Safety Checks • Check for possible cracked heat exchanger. • Visually inspect the heat exchanger. • Observe the flame pattern and color. • Observe the flame for changes when the fan turns on. • CO reading at the nearest supply register

43. Equipment Types Atmospheric Combustion & Sealed Combustion

44. Atmospheric Combustion Fresh, combustion air is drawn in through combustion air sources Combustion by-products are exhausted out the vent stack Fire (combustion) and exhaust are open to the house

45. Atmospheric Furnace • The flue gas chamber is open • The burner chamber is open Draft diverter Burners If you can touch the flame or the flue gas it is NOT sealed combustion

46. Induced Draft Furnace • This is NOT sealed combustion • The flue gas chamber is closed • The burner chamber is not Sealed flue gas chamber If you can touch the flame or the flue gas it is NOT sealed combustion

47. Draft diverter Atmospheric Water Heater • This is NOT sealed combustion • The flue is open • The burner chamber is sealed • Combustion air is not Combustion air inlets Sealed combustion chamber If you can touch the flame or the flue gas it is NOT sealed combustion

48. Sealed Combustion Fresh, combustion air is drawn in through outer part of the vent stack Combustion by-products are exhausted out the center part of the vent stack Fire (combustion) and exhaust are completely sealed off from the house

49. Sealed Combustion Sealed combustion air inlet Sealed flue pipe All sealed combustion units have a condensate drain 90%+ efficient Sealed combustion, you cannot touch the flame or flue gas

50. Sealed combustion air Sealed flue vent