My New Fancy Furnace

27 Oct 2015 8:00 AM | Anonymous
by Donald Kennedy, P.Eng.

I recall a quote that plays on an old saying “The more things change the less they stay the same.”  The first session I ever attended at an ASEM conference was about how people have been managing activities from long before 1990.  Somehow the pyramids were built using teams of specialized labor.  Wikipedia lists Mir Abdul Karim and Mukkarimat Khan as the cost management leads on the building of the Taj Mahal and they performed their jobs 500 years before the benefit of web based ERP accounting systems.  Those of you who attend my presentations at ASEM annual conferences know I am not convinced our present state of management practice is anywhere near optimal and that we can learn from things that worked in the past.

In 1983, I lived in a house heated by a gravity furnace.  The flame had two settings, small (the pilot) and large (the main burner).  No fan and no sensors other than the thermostat.  Today that 70 year old furnace still works and has never been serviced, since there is almost nothing to wear out.

In my current residence, the 2010 model furnace is unreliable due to intentional engineering decisions.   It has a safety feature that shuts the fuel off if there is no flame.  Good idea, but the flame sensor is temperamental and cannot tell it is in the middle of a hot flame when a thin film of oxide is present.  I cannot see any buildup, but a quick wipe with steel wool gets it working again.  If I am away when the sensor quits, the house may freeze - because the engineers could not think of a better way to tell if something is extremely hot other than this finicky sensor. 

Secondly, my furnace shuts the burners off if it believes the flue is plugged.  This is a good feature, except that it can be triggered by many different scenarios.  When triggered, the furnace shuts down and will attempt to restart when the thermostat signals low temperature.  The plugged-flue sensor needs a neutral pressure to reset as would normally happen if the flue was not plugged.  As part of another system, there is a small fan that creates negative pressure while the burners are on to prevent combustion gas escaping into the house.  If the plugged-flue sensor shuts the burners off and the furnace tries to restart before the small fan stops spinning because of inertia, the combination keeps the fuel shut off and the flue fan starts and keeps running until it is manually rebooted by cutting the power.  Again it makes it difficult to leave the house in winter for more than a day for fear of requiring a manual reboot. 

The motives behind the improved furnace design are admirable such as safety and energy efficiency, but the unintended consequences of an unreliable system introduce more safety and efficiency concerns.  Design engineers are often not good at establishing the bases for their designs, or rather it is typically not their job to do so.  The requirements are set by the stakeholders.  These stakeholders can benefit from people knowledgeable in EM fundamentals and who believe in the value of systems that work fine.  In operations management courses EM’s are taught case studies where one company may succeed and grow by building upon systems that work and others are run into bankruptcy by the unintended consequences of changes based on good intentions without a solid history of success.
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Dr. Kennedy spent most of his career on heavy industrial projects in the fields of oil & gas, pipelines, electrical power generation and mining.  He has also lectured at universities on financial and project management. He has written two books and dozens of articles on the practical application of management theories, with special interest in how our own misperceptions often lead us down paths of fantasy.  

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