How Hot Did It Get

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Low TemperatureIgnition of Wood Presented by Jeffery H. Warren, Ph.D., P.E., CSP, C.F.E.I.

How Hot Did It Get?

www.warrenforensics.comPresented byJeffery H. Warren, Ph.D., P.E., CSP, C.F.E.I.S. Dyer Harris, Ph.D., P.E., C.F.E.I1The way I want to work the rest of the class is as follows:

First, I want to spend about 15 minutes describing the loss.

Then I want your group to discuss the case answering the questions provided. We will then take 20-25 minutes to go over your findings.

Clemson, SC Fire: 11/11/1998Startup: 2/18/97 www.warrenforensics.com

Typical Installation

www.warrenforensics.com2 by 6 studsCement BoardStainless Steel Sheet2 by 6 or 2 by 12 BlockingMounting Bracket Detail www.warrenforensics.com

Clemson, SC www.warrenforensics.com

Mounting BracketClemson, SCFigure 6 8168 report appendix 3www.warrenforensics.com

Intact SheathingFire OriginWood BlockingClemson, SC- Back of Cheesemelterwww.warrenforensics.com

Extensive Heat DamageClemson, SC

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Fire OriginBlocking RemainsDurock

www.warrenforensics.comTrussville, AL Inspection 3/10/99

www.warrenforensics.comNiceville, Florida Inspection 3/26/1999Startup Date: 9/30/97 www.warrenforensics.com

Heat DamageTullahoma, Tennessee www.warrenforensics.com

The Warren Group Laboratory

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www.warrenforensics.com Insert Figure 1, Appendix 9 W8168 www.warrenforensics.com

Sebring, FL

www.warrenforensics.comReport 60093www.warrenforensics.com

Left Mounting BracketRight Mounting BracketGas Control Valve Knob

Fire TriangleIgnitionSourceFuelOxygenwww.warrenforensics.comProlonged, especially cyclic, exposure to heat decomposes wood.

Temperatures do not have to be high to cause charring.

Carbonaceous material self-heats from C + O2 CO2

Key: Can the heat be removed (conducted out) faster than it is generated? If not, ignition and fire can resultwww.warrenforensics.comAn estimate is given by Fouriers equation, a century old.

Note the factors involved: T, x, q, material , and time(leave the solution details to us)

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A Modine Heater enclosed and jammed into a closetHot exhaust flue pipewww.warrenforensics.com

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www.warrenforensics.comFire place insert test, full scale with exemplar

Allegations MadeRegulator defectively manufacturedLeaks existed before the fireLever arm was not inserted in diaphragm platewww.warrenforensics.com

Testing Regulator inch NPTANSI Z21.18 gas appliance regulatorANSI Z21.80 line regulatorRated for 250,000 BTUH of natural gaswww.warrenforensics.com

Testing Apparatus: OvenConvection oven with capacity to 600F

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Results: Housing IntegritySome leakage when exposed to temperatures at or above 500FHousing did not leak below 500FOnset of leakage correlates well with first stage degradation of NBR diaphragmAmount of leakage not always greater when exposed to higher temperature

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Conclusions:Regulator operated at temperatures well above manufacturers stated limitPost fire examination and testing of regulators can be used to determine fire exposure and explain post fire damage

www.warrenforensics.com www.warrenforensics.comWho has the first question? PointA285.9378.9429393.6227.6338440.9375.9119.7272.3418.3333.6116265.7401.5320.6115.4259.3369.5301.5115.3254.2341289.183.9139.8101.3106.7

Test 1: Cheese MelterTest 2: Cheese Melter & Steak GrillTest 3: Cheese Melter & Fryer with WaterTest 4: Cheese Melter & Fryer with GreaseLocation in WallTemperature FMaximum Temperature Distributions in Wall at Point A

DataAMaximum Temperature Distributions in the Wall at Point AInside of Cheese MelterBack of Cheese MelterBolt Head LocationBetween Stainless Steel & DurocFront of 2 x 12 Wood BlockingBack of 2 x 12 Wood BlockingInterior Surface of Back Wall PanelPoint A: Test 1285.9227.6119.7116115.4115.383.9Point A: Test 2378.9338272.3265.7259.3254.2139.8Point A: Test 3429440.9418.3401.5369.5341101.3Point A: Test 4393.6375.9333.6320.6301.5289.1106.7

PointB311.5403.4465.9420.2252.9357.2495.2406.1113.2269.3461.9359.9113.4258.3411.2337.9109.9245.1345.3307.8104.7209.7213.8232.283.6137.6102111.5

Test 1: Cheese MelterTest 2: Cheese Melter & Steak GrillTest 3: Cheese Melter & Fryer with WaterTest 4: Cheese Melter & Fryer with GreaseLocation in WallTemperature FMaximum Temperature Distributions in Wall at Point B

DataBMaximum Temperature Distributions in the Wall at Point BInside of Cheese MelterBack of Cheese MelterBolt Head LocationBetween Stainless Steel & DurocFront of 2 x 12 Wood BlockingBack of 2 x 12 Wood BlockingInterior Surface of Back Wall PanelPoint B: Test 1311.5252.9113.2113.4109.9104.783.6Point B: Test 2403.4357.2269.3258.3245.1209.7137.6Point B: Test 3465.9495.2461.9411.2345.3213.8102Point B: Test 4420.2406.1359.9337.9307.8232.2111.5

DataMaximum Temperature Distributions in the Wall at Point AInside of Cheese MelterBack of Cheese MelterBolt Head LocationBetween Stainless Steel & DurocFront of 2 x 12 Wood BlockingBack of 2 x 12 Wood BlockingInterior Surface of Back Wall PanelPoint A: Test 1285.9227.6119.7116115.4115.383.9Point A: Test 2378.9338272.3265.7259.3254.2139.8Point A: Test 3429440.9418.3401.5369.5341101.3Point A: Test 4393.6375.9333.6320.6301.5289.1106.7Maximum Temperature Distributions in the Wall at Point BInside of Cheese MelterBack of Cheese MelterBolt Head LocationBetween Stainless Steel & DurocFront of 2 x 12 Wood BlockingBack of 2 x 12 Wood BlockingInterior Surface of Back Wall PanelPoint B: Test 1311.5252.9113.2113.4109.9104.783.6Point B: Test 2403.4357.2269.3258.3245.1209.7137.6Point B: Test 3465.9495.2461.9411.2345.3213.8102Point B: Test 4420.2406.1359.9337.9307.8232.2111.5