Aucun titre de diapositive

1
CMOS 2005 - An educational tool to estimate how
much air urban processes use locally (675) Lewis
Poulin, CMC, email lewis.poulin_at_ec.gc.ca
Objectives Model estimate volumes of air used
by various urban processes Compare these volume
estimates against volumes humans need per
day Method (1) Computing baseline air consumption
rates (2) Defining input parameters for air
consumption model (3) Estimating air consumption
volumes for various processes (4) Some comments
on estimated volumes of urban air consumption (5)
Comparing air consumption volumes of different
lifestyles (6) Future work (7) Conclusions
(5) Comparing consumption volumes of different
lifestyles
(3) Estimating air consumption volumes
lt Figure 5.1 Weekly air consumption balance of
2 different single lifestyles
lt Figure 3.1 Estimated daily litres of air
consumed for single units of each process shown
here as multiple of human-days (h-d) of
air Examples 1 local small car /hour uses 29 h-d
of air 1 local SUV / hour driving uses 40 h-d of
air 1 local truck uses 111 h-d of air

• Person A (B) has deficit (surplus)
• of -36 (2) human-days of air/week
• It would take 19 of (B) to balance (A)

(1) Computing baseline air consumption rates

• lt Figure 3.2 Estimated litres of air
• consumed by total units of each process as
  multiple of population-days (p-d) air
• All local small cars uses 17.1 p-d of air
• All local SUVs use 15.9 p-d of air
• All local trucks use 133 p-d of air
• All airplanes taking-off use 168 p-d of air
• All airplanes landing use 332 p-d of air

lt Figure 5.2 Weekly air consumption balance of
2 families of 4 each with different lifestyles
Assumptions for baseline air consumption
calculations 1 Average human consumes 9700 (l)
air/day (human-day 9700 litres air) 1
human-day (h-d) air total volume air for 1
human/day approximately 9700 litres 1
population-day air total volume air for full
population/day (N people x 1 h-d) 1 leaf
produces 5 ml O2 / hour. Use this data to
estimate O2 production from a tree 1 average
tree, crown 6.1 m gt N leaves 5mlO2/leaf/hr
8 hours1(l) air/.21(l)O2 1 (l) 4-strokevolume
cylinder (rpm/2)60 min, 1 (l) 2-stroke vol
cyl rpm60 min 1 lawn 58m2 lawn gt air for 1
human/day 1 Airbus A320 enginehttp//www.grc.nasa
.gov/WWW/K12/airplane/ngnsim.htm 1 pesticide, gas
station, paint shop gt W x D x H (m3) gt
litres of air impacted / day
Family A (B) has deficit (deficit) Of -275 (-28)
human-days of air/week
(4) Comments on estimated volumes of urban air
consumption

• Economic tools to promote conservation of our air
• What about a clean air trading system at the
  local level?
• Each is allotted a sustainable daily volume of
  air. Those with an air deficit (drivers?) could
  trade (?) with those who have surplus.
• Apply clean air trading system locally, and also
  globally
• Better educational tools to help clarify impacts
  ex 1 hour of driving (4.3 l) locally taints the
  air 40 people need in one day.

lt Figure 4.1 Estimated total air consumption by
category as multiple of population-day (p-d) of
air

• (6) Future work
• Include more processes, broader ventilation
  information
• Ex Include particulates stirred up by cars,
  industry exhaust
• Confirm air volumes impacted by vegetation
  parameterize air cleansing benefits of
  vegetation, wetlands
• Use real-time municipal GIS systems as inputs
  into model
• Consider using model outputs as real-time inputs
  into chemical models (as real-time inventories or
  emissions files?)
• Develop web-page format so individuals and
  communities can easily generate local versions of
  air consumption charts
• Include this type of air consumption data into
  environmental impact assessments for various
  infrastructure projects

• Vehicles use 177 p-d of air/day
• Airplanes use 680 p-d of air /day
• Modeled community has net air balance of -680
  p-d, i.e. activities consume 680 times the volume
  of air total population needs/day

Figure 1.1 Estimated litres of air used /
baseline process as multiple of human-days
(h-d) 1 lawn or 1 tree each generate about 1
h-d of fresh air, (shown as positive on
graph) 1- 1 (l) 4(2)-stroke engine, _at_ 2000
(2000) rpm for 1 hr uses 9 (31) h-d of air (no
dilution) 1 Airbus A320 engine (30 min idle, 1
min full power _at_ T-O) uses (596x10E3) h-d of air
(no dilution) NOTE Processes that taint the air
are shown as negative values on the graphs With
above baseline numbers, other air consumption
patterns are estimated
ltFigure 4.2 Per day, all airplanes use about 6
of the air available in a fictitious box of 20
km x 25 km X 0.3 km over the modeled
region. Combustion engines use 2 /day
(2) Defining input parameters for air consumption
model

• (7) Conclusions
• An average human needs approximately 9700 litres
  of air daily, defined here as 1 human-day (h-d)
  of air.
• Its estimated a 1 litre 4-stroke engine _at_ 3000
  rpm, driving locally for 1 hour pushes the
  equivalent of 9 h-d of air through its engine.
  This approach is used to model various engine
  sizes.
• An airplane engine simulator was used to model 1
  A320 engine.
• Other urban processes modeled gas station, body
  shop, pesticide application
• Numbers loosely based on the island of Montreal
  were used
• Modeling of air consumption patterns helps to
  highlight how we use the air and could help
  target action to help clean the air
• Data from such models could help in the
  development clean air initiatives and serve as
  live inputs to chemical models.
• Communicating air pollution information in terms
  the public can better relate to may increase
  public interest and action to help keep the air
  clean.

Figure 2.1(above) Input parameters defined for
air consumption model. Note that numbers on graph
must be multiplied by denominator in legend.
?Figure 2.2 Estimated volumes in litres of
various engine cylinders used in air consumption
model
Figure 4.3 Under a stagnant ridge it would take
7 days for our urban processes to consume over
half of the air in a box 0.3 km deep over the
region (no external mixing)