The Chimney Effect in your home.

The whole idea behind winterizing your home is to save on energy costs, doing the right thing for the environment, and improving your own personal comfort – all of it centers around the simple fact that houses do have a Chimney Effect. 

There are articles here and there that will assure you the Chimney Effect can be eliminated, I don’t agree.  We are trying to significantly reduce the stack effect but, we need to keep our feet firmly on the ground and realize we will never completely eliminate the Chimney Effect to a bare minimum.  Don’t forget our two major rules, 1~ what we do must make a significant impact and 2~ it needs to be cheap.

  • Caulking around windows and doors will help but not much! 
  • Sealing up the Tub/Shower hole will accomplish a lot, caulking windows – “not so much!” 
  • Closing off the “Never Used Floor Drain” will accomplish a lot!  
  • Obvious things like closing basement doors and windows will accomplish a lot! 

For the longest time the conventional wisdom was that as the “warm” air exits towards the top of the building it creates a vacuum at the bottom and as a result Cold Air Penetrates.  This thinking has been revised and updated -

The Chimney Effect – air that enters the house as cold air rises inside the house because of the interior pressure differentials and DENSITY, as it warms the air is actually forced out by the more dense cold air entering.  The warm air is now far less dense and is forced to exit up and out the top of the building. The warm air is actually pushed upward by cold air that is more dense.  The cold air will follow a PATH.  The trick to solving this problem is to restrict or eliminate the path for the air. The volume of air that moves can be enormous and obviously the Heat Loss is equally as large.   

The latest thinking centers around a very basic thought; heat always moves towards cold!  Warm air is always absorbed into colder air.  As cold air that is far more dense enters the house, a.k.a. Cold Air Penetration, it actually forces the warm air out. 

The movement of the air will always follow a PATH and it is the path that’s what we are trying to close.  All this is very basic and rests on common sense.  Shortly we need to look at Air Density

By the way, today’s picture shows you almost nothing but we didn’t know how to picture air moving. 

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