Heat Transfer in the Mind of a 7 Year Old

By Nick Baker, EIT, LEED AP BD+C

I deal with heat transfer every day. Everyone does.  It is really a basic principle; if you place something cold on something hot, the cold thing gets warm.  That is heat transfer. It is that simple.  Working as a Mechanical Engineer specializing in Commissioning in the Heating, Ventilation and Air Conditioning (HVAC) industry, I understand the deeper reasoning behind heat transfer.  I get the complexity of mass and flow and how they will affect heat transfer.  Those of you who are HVAC engineers may know how exciting heat transfer is.    In all seriousness, I rarely talk about my work at home with my wife or children.  I have come to learn that they do not find heat transfer, or anything related to HVAC, really that interesting or fun.  I accepted this, up until about a month ago.

I was filling the bath for my seven year old daughter.  Using my understanding of heat transfer, I turned on the water a bit warmer than I wanted the end bath temperature to be; I know that enough heat will be transferred from the mass of water to the mass of cast iron claw foot tub.  I walked away to find her towel, and maybe a minute later I returned and there she is, bent over the tub, splashing water up the back of it.  “What are you doing?” I asked.

“I am warming my back rest,” she said, as she continued to splash water.  I looked at her quizzically so she would elaborate. Remember, she is seven and knows everything (I hear this will continue through her twenties!)  “The back of the tub is cold and the water is warm so I splash it up to warm the back of the tub.”

She gets it! Through her critical thinking and experimentation, she had figured out heat transfer!  I took this opportunity to describe the concept of heat transfer, explaining what’s happening when she splashes the hot water – the energy from the mass of the hot water is transferred to the lower energy of the mass of cast iron tub, causing the tub to get warm.  She smiled at me and said, “In that case can I skip school tomorrow and come to work with you?”

Follow Nick on Twitter @NBaker_WH