Christmas Tree Fire Size Prediction Competition

On Tuesday, December 12, 2017 the Department of Fire Protection Engineering at the University of Maryland will host its fourth annual  competition to predict the burning behavior (heat release rate or HRR) of a Fraser Fir Christmas tree from ignition to final burnout.

Students, faculty and researchers from Fire Safety Science and Engineering programs around the world are invited to join us in this year’s  competition. The highest individual and highest group scores (i.e. the average scores of all submissions from a single research team or program)  will be announced to all competition participants and the research team with the highest average group score will also earn the coveted Golden  Pinecone Award.


How to participate: Generating and Submitting Your Predictions

This year, the submission (and generation of) predicted heat release rate (HRR) curves is easier than ever, thanks to the efforts of several  members of the Fire Research Division at NIST.
Visit to use a custom-made app that allows you to ‘build’ (and submit) your own fire by  adjusting just four parameters that define:

  • Fire Growth Rate
  • Peak Heat Release Rate (Peak HRR)
  • Duration of Steady Burning
  • Fire Decay

In this app, after you click submit, an email will be generated that contains the four parameters defining your HRR curve. In this email, please remember to add your name, email address and lab affiliation if you wish to receive credit (and final competition results) - be sure to CLICK SEND so that we receive your submission.

If you prefer the old system – submitting HRR predictions in massive spreadsheets or .txt files – you may submit those files directly to These prediction files should be formatted in two columns with a 1 Hz resolution in the format: [time (s) | HRR (kW)].

The Scoring System

Points (100 possible) will be awarded in five categories, as listed below:

Peak Heat Release Rate Up to 20 points; 1 pt for each 25 kW from measured value
Total Energy Release Up to 20 points; 1 pt for each 1 MJ difference from measured value
Time to Peak Heat Release Rate Up to 20 points; 1 pt for each 1 s difference from measured value
Duration in which HRR exceeds 80% of peak HRR Up to 20 points; 1 pt for each 1 s difference from measured value
Duration in which HRR exceeds 50% of peak HRR Up to 20 points; 1 pt for each 1 s difference from measured value

Competition Details

The 2017 Competition Tree: Fraser Fir 

This year’s competition tree is a Fraser Fir - it will be held in laboratory storage (relative humidity = 50 %; temperature = 23 °C) without water for 17 days prior to burning. 

The competition tree is approximately 2.0 m tall and 1.1 m wide. The tree’s mass on December 5, 2017, was roughly 12.0 kg (note: the tree will continue to dry out prior to testing and has lost roughly 3 kg since its purchase on November 26).

Experimental Procedure

Christmas tree mass loss rate will be measured continuously at 1 Hz using a Mettler Toledo mass balance with a 0.1 g precision. A constant heat of combustion will be assumed – ΔHc = 17.7 kJ/g [Mell et al. 2009] – to convert this to HRR.

For ignition, a circular wick (6 mm thick Kaowool Insulation board with outside and inside diameters of 30 and 26 cm, respectively) filled with 40 mL of heptane will be placed below the lowest branches of the tree. Ignition (time t = 0 s). will be defined as the earliest time at which measured HRR exceeds 50 kW.

Reference Materials

Previous Experimental Measurements of Christmas Tree Fires:

Stroup, D.W., DeLauter, J.L., Roadarmel, G., “Scotch Pine Christmas Tree Fire Tests,” NIST Report of Test FR 4010, National Institute of Standards and Technology. December 1, 1999. Downloaded November 1, 2017.

Detailed Christmas Tree Fire Simulations Results:

Mell, W., Maranghides, A., McDermott, R., Manzello, S.L., “Numerical Simulation and Experiments of Burning Douglas Fir Trees,” Combustion and Flame 156: 2023-2041. 2009. Downloaded November 1, 2017.

Results from the 2015 Christmas Tree Fire HRR Prediction Competition