The Palmer dollhouse is a great tool for demonstrating thermal imaging concepts in a controlled environment. We recommend making a few changes to the dollhouse listed here:
- First, build it out of plywood for a longer demonstration (3/8 inch is acceptable). Use screws to hold it together and caulk the seams.
- Second, line the lower left room (fire room) with drywall to also show the benefits of dry wall as an insulator and firewall. It will initially hide the heat signatures. Thermal bridging will be visible through the screws initially before heat transfer emits through the drywall and then the plywood.
- Screw a lag bolt into the back of the doll house in the first or second floor fire compartments on the right side (away from the fire room).
- In the compartment directly over the fire, we recommend using this room as your isolation example room. By keeping it sealed during the entire burn you can demonstrate the benefits of closed doors. Ensure this room is tightly sealed and caulked.
- Purchase 2 large kitchen sponges for the demonstration. When the fire is in the growth stage, simply place the dry sponge into the fire and watch how quickly the sponge burns away (make sure its dry. Then take the second sponge and soak it with water and wrung out the excess water. Then place it into the fire and watch how long it takes for the sponge to burn away.
Here are some key topics to cover:
- **Basic TIC operation: **
General operational knowledge is known as requisite knowledge which is required by NFPA 1010 for all new firefighters. Therefore, first cover how to set up the TIC in either TI basic or another application mode prior to starting the burn. Ensure they know how to switch back and forth. Also, ensure that they all understand that IR energy travels in straight lines. So, if they stand at an angle, they will not detect or see the full strength/energy of the fire.
Second, during the incipient stage, have 3-4 students kneel and view the fire compartment for the following concepts:
- Gain Demonstration: Demonstration of high & low sensitivity & compare them to mixed gain mode. Notice how when the heat increases if it changes the firefighters ability to see objects in the cooler areas and if they can see details through the colorization.
- Colorization: Place TICs side by side and compare colorization of temperatures. If you are using all the same brand/model of TICs, you may have them compare TI Basic vs other application modes.
- Convection current identification: Have the students view the heat exhausting out of the first compartment and into the second compartment. Notice the thermal layer height and the differences in different models in how they display the thermal layer.
- Thermal Layer Identification: Have the students identify the thermal layer in gray scale and in color in the first compartment and the second compartment. Then open the floor door to the second floor allowing heat to move to the second floor. Notice the thermal layer on the first floor (second room) lifts but the fire room intensifies.
- Size-up Demonstration: After a few minutes, have them conduct a 360 and look for thermal bridging and non-uniform patterns. This is a great opportunity to show them different application modes and how they display colorization earlier vs later such as: Survey mode in the Seek, Search & Rescue Mode in the FLIR KXX/Search mode in the new FLIR K75/K85, Electronic Thermal Throttle in Bullard, Size-up Mode in Argus, etc. Areas to notice would be nails or screws in the Palmer Dollhouse as they heat up. Also note the heat transfer pattern in the areas of the flow path.
- Distance & Target Demonstration: Have the students stand 8’ away and view the fire room. Then have them slowly back up until they can no longer see colorization. This should be done in TI Basic. You will note that the Seek Thermal TICs can detect heat and colorize at up to 900’ whereas many of the other models will switch back to high sensitivity or lose colorization at 15-30’. Any student with a TIC other than Seek have them drop to one knee when they lose color. The students with the Seek Thermal TIC will be able to walk back approximately 900′ and still see color. Please note this demonstration is in ambient temperatures and in a fire environment, the ability of the TIC to colorize superheated surfaces will be based on the optical density of the smoke and moisture content.
- Target recognition: Students should stand at 8-10’ away and then with a gloved hand, have the students view your gloved hand away from the heat source. Then slowly lower your hand in front of the heat source. Certain models will cause your hand to appear to wash out or disappear.
- Scanning demonstration: Have the students start their scan from away from the Palmer Doll house and scan passing the doll house. The instructor should stand just slightly to the side of the doll house so that when the dollhouse and the instructor come into the field of view they see a difference in how the instructor is displayed with the heat source behind them. Also, note if the TIC freezes if they scan too fast or when it switches gains.
Other considerations:
- **Limitations of TICs: ** Show reflective surfaces, and how smoke or glass can affect readings. This can be done by placing reflective aluminum tape on the side or back of the doll house.
- **Fire behavior: ** Use the dollhouse to illustrate flow path, ventilation effects, and fire spread, tying in what’s visible to the TIC versus the naked eye.
- **Decision-making: ** Set up scenarios where crews must choose entry points or ventilation tactics based on TIC feedback and you may use a garden hose or spray bottle to demonstrate stream placement to show how the surfaces change when they are cooled.
Extinguishment and overhaul:
** Take a garden hose, portable water can extinguisher, or small hose line and demonstrate stream placement (in various forms) and let them watch the effects with the TIC.
**Overhaul: The instructor should “extinguish the fire” (knock it down until there is no visible flames and have them check areas for heat and point out what still needs cooling (internally and externally). They will be surprised how much heat is remaining and it allows the student to become more engaged by demonstrating their knowledge of thermal imaging data interpretation.
Lastly, pry the front of the doll house off and show the burn pattern. The second-floor room directly over the fire is basically untouched due to being isolated.
Please see our version of the Palmer doll house plans for your reference here:
https://drive.google.com/file/d/1DBqNG3lTjj0Bw7LQ1JNTZ0DPii46M2Ej/view?usp=sharing
