Radon and Energy Efficieny

[FIELDRW@aol.com]

In a message dated 3/8/00 3:56:24 PM Central Standard Time, 
LGrimm@ADMIN.UCLA.EDU writes:

<< Perhaps Drs. Fields or Cohen can answer this:
 
 In an EPA training session for Radon, I saw a graph/study that indicated
 that it made no difference whether a house was energy efficient (tight
 construction) or inefficient (older, looser construction) with regards to
 Radon levels and all other factors being equal.  I carefully questioned the
 instructor, because the EPA literature always indicates that Radon levels
 are higher in an energy efficient home.  So which is it?  Is the EPA
 literature perpetuating a myth (my thoughts when the instructor insisted the
 graph was accurate) or does it make a difference?
  >>

Larry,

Was the instructor talking about year long radon measurements in the upper 
living area or short term radon measurements performed under closed house 
conditions in the basement?  They may have been talking about two different 
things.  

Fletcher et al. in a limited survey as far back as 1983 reported that energy 
efficient homes had higher radon concentrations in New York State.  These 
were primarily homes using solar energy.  What is meant by energy efficiency 
often changes by region of the country?  Some energy efficient homes have 
poured concrete foundations, while other energy efficient homes have block 
foundations.  Homes with poured concrete generally have lower radon levels in 
the basement.  Some energy efficient homes have forced air, while others do 
not.  Homes with forced air generally have less difference in the radon 
concentrations between the basement and upper living areas. In the Midwest, 
energy efficient homes generally have less air entering the home from the 
living area level (tight windows, etc.), which would increase radon 
concentrations on the living area (but may have no effect on the basement 
concentrations).  However, this may be offset by less stack effect, which 
would decrease radon concentrations. There are so many potential 
possibilities of home factors that it is difficult to generalize about homes. 
 However, you can safely say that radon source strength is the primary factor 
determining whether or not a home has elevated radon.  Home factors 
(foundation material, etc.) may have more influence on the basement radon 
concentrations as compared to the upper living areas, and vice versa.  When 
you specify that certain housing characteristics have an influence on radon 
concentrations, you really need to specify the location of the radon 
concentration within the home.   

Bill Field
bill-field@uiowa.edu


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