Lutes, C.C. “Temperature Methods for Vapor Intrusion Sites: What, Where, When, How, and Why “ Presented at EPA Workshop on: Indicators, Tracers and Surrogates (ITS) for Chlorinated Vapor Intrusion (CVI) – Pursuing Additional Observations at AEHS East Coast Conference, October 16, 2018.

1. EPA Workshop on
Indicators, Tracers and Surrogates (ITS) for Chlorinated Vapor
Intrusion (CVI):
Temperature Methods for Vapor Intrusion Sites
What, Where, When, How and Why?
34th Annual International Conference on Soils, Sediments, Water, and Energy
Amherst, Massachusetts
Oct. 16, 2018

2. Temperature Methods
1. What? Temperature’s role in the vapor intrusion conceptual site model
2. When? Temperature variability at various scales – diurnal, seasonal etc.
3. Why? Are these seasonal factors/rules good indicators?
4. How? Current guidance document language
5. How? Low cost data sources and measurement equipment available
6. How? SOPs – can be pretty simple for temperature
7. Suggestions for future data gathering and interim thoughts for
practitioners
Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.

3. Stack
Effect
Review
Figure Credit:
Quirouette, R. L., and
B. Arch. Air pressure
and the building
envelope. Ottawa:
Canada Mortgage and
Housing Corporation,
2004.
Equation Credit: Hui,
S.C. 2003. Lecture: Air
Movement and
Natural Ventilation.
Department of
Mechanical
Engineering, The
University of Hong
Kong. Used by
Permission from Dr.
Hui. Available at
http://www.arch.hku.h
k/teaching/lectures/air
vent/sect03.htm.

4. What can we measure? from the conventional
Conceptual Site Model (CSM) of Soil‐Gas Intrusion
Four Categories‐of‐Variables for Chlorinated VOC (CVOCs ) components
4
Dissolved CVOC contamination
LT Diffusion
Vadose zone
Building
zone of
influence
Wind effects
Indoor Air
CracksQsoil
Air
streamlines
Convection
Top of capillary
zone
Water Table
Stack effects
Mixing in indoor
air and inhalation
Advection
Diffusion
Phase partitioning
Cgw to Csoil gas
Mod. from slide by M. Bolas, Ohio EPA, presented Jan. 2006
CVOC contamination
CVOC contamination
1 - Driving Forces
2 - Building factors
3a
3b
4
4 (x,y,z,t)
3a
(x,y,z,t)
3b
(x,y,z,t)
2
#2 (=100x #3)
1 (x,y,z,t)
Radon (Rn)
Source, ½ life
limits distance
Rn &
CVOC
Bottom Line = ONLY indoor air conc. can represent ALL variables/factors involved
& we want supplemental measures/metrics that can represent as many as possible
Bldg. are complex incl. Pipe Flow pathways
CVOC
Source
Term
Metrics e.g.,
Temperature
Pressure
Tracers

5. Why? Temperature
Drives Temporal
Variability in Many
Buildings
• Indoor/Outdoor T
Differential 0 C to >40 C
• Diurnal, seasonal and
climatological cycles
Figure from:
http://www.daviddarling.info/encyclopedia/T
/AE_thermal_mass.html

6. How? Climate Zones are Your First Clue
• Different climate zone systems
give us short term or whole
winter measures of how cold it
gets
USDA Plant Hardiness Zones (Reprinted from
https://planthardiness.ars.usda.gov/PHZMWeb/Downloads.aspx)
IECC Climate Zone Map (2012 IECC –
International Energy Conservation
Code) – Based on Temperature and
Moisture

7. Season and Temperature as Indicators
• Season cited in number of state VI guidance documents as
important to consider for characterization of VI
• Many northern states require one or more winter indoor air
sample
• Some specify multiple seasons for sampling with one in winter
• Data available from numerous sites in temperate climates show
generally higher indoor CVOC concentrations in winter
• Several studies (Johnston & Gibson, 2013, Barnes and McRae
(2017) suggest higher indoor CVOCs during the cooling season –
but appear to be exceptional circumstances

8. Temperature Outdoor vs. TCE
[‘XY(2x2)’]
8
0 0.00
0
0.5
1
1.5
2
2.5
3
0 10 20 30 40 50 60 70 80 90 100
TCE (ppbV)
Outdoor Temperature (degrees F)
24 hr Average TCE in Indoor Air (ppbv) vs Outdoor Temperature (degrees F) (N=579)
98% of Negatives are True (TN)
ASU‐SDM house statistics by J Kurtz
36% of the data ‘Indicated’ to have higher TCE conc. were found to have higher TCE
36% of Positives are
True (TP)
Indicator Positive side Indicator Negative side
True means indoor air results confirm indicator’s prediction

9. Heating
Degree Days in
Indianapolis
Duplex As
Indicator
9
0
2
4
6
8
10
12
14
16
18
20
0 50 100 150 200 250 300 350
PCEconcentration(µg/m3)
Heating Degree Days)
Weekly Total Heating Degree Days vs. PCE Concentration 422
Base South; Mitigation Off or Not Installed Data Only
ColdestWarmest

10. Temperature Differential – Another Potential
Surrogate
Time Series Analysis Results
• The strength of the stack
effect predicted by the
temperature differential
between the 422 basement
south and outdoors was
significant at the 1% level.
• Increasing strength of the
stack effect was associated
with higher VOC
concentrations, not primarily
high values in and of
themselves
• Data from EPA/600/R‐15/070
| October 2015 ‘Third Indy
Report’
422 Basement North Temperature (C)
422 Basement South Weekly [PCE]
PCE Data from Indy Test House: Jan 2011 to Feb2012 (includes
locally weighted scatterplot smoothing line [blue], with a 95%
confidence interval [shaded])

11. Key Time Series Conclusions from
Indianapolis
• The change in the differential temperature and
thus stack effect strength was more important
than the absolute value of the differential
temperature.
• Indoor air concentrations of VOCs are expected to
be high when the weather is getting colder, but
would not necessarily be expected to be as high
during a period of sustained cold weather.
• Not all winter sampling times are equivalent.

12. How? – Temperature Data Sources
• Differential temperature – almost always available,
because
• Inside temperature often as easy as “where do you set your
thermostat in winter?” “how about in fall?”
• Historical outside temperature data for thousands of locations
cataloged either for specific period or normal values
https://www.ncdc.noaa.gov/cdo‐web/
https://www.wunderground.com/history/
https://www.ncdc.noaa.gov/cdo‐web/datatools/selectlocation
• Its Free!!!! You can do it Retroactively
• Want to Measure Yourself – Inexpensive loggers are
available for <$100
• Some Pressure instruments give temperature as a bonus
Temperature logger images reprinted from https://www.microdaq.com and www.onsetcomp.com
Temperature and pressure logger from www.omega.com, Thermostat from https://sites.psu.edu/mfsblog/2015/02/08/how‐does‐
lowering thermostat save energy/

13. How – Retroactive Temperature Analysis of
Existing Sites
• Do you have sites where you have numerous historic rounds?
• As long as you have sample date/time, you can look up external
temperature on line…..
• Then you have a data set that you can use to check differential
temperatures predictive value
• Do you have survey forms that document heating status?

14. How? – Advanced Predictions On‐line
• Temperature – readily
available forecasts,
probably sufficient short
term accuracy for purpose
Graphic reprinted from:
http://blog.extension.uga.edu/climate/2015/07/when‐weather‐apps‐go‐
bad/
http://www.cpc.ncep.noaa.gov/products/forecasts/