Risico verspreiding covid19 via aerosolen in een klaslokaal
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Input Parameters |
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Value |
Value in other units |
Source |
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Surface area |
sq ft |
= |
m2 |
Typical value |
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Height |
ft |
= |
m |
Typical value |
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Volume |
m3 |
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Faculty / instructors |
person |
Typical value - Assumed constant |
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Surface area per student |
sq ft |
= |
m2 |
CU-Boulder: 60-120 sq ft / person. UNC = 36 sq ft / person. See Readme |
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Students |
people |
You can change this number directly, then the previous input of area per student is not used |
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Breathing rate (instructor) |
m3/h |
Estimated from Miller et al. (2020), for someone talking a lot |
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Breathing rate (students) |
m3 / h |
Estimated from Miller et al. (2020), for someone occasionally talking |
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Duration of class period |
min |
h |
Typical value |
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Ventilation w/ outside air |
h-1 |
L/s/per |
First value is the same as "air changes per hour". Second is used in most guidelines now |
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Decay rate of the virus |
h-1 |
Average of literature values (0 and 0.62), Miller et al. (2020) |
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Deposition to surfaces |
h-1 |
Buonnano et al. (2020), Miller et al. (2020). Could vary 0.24-1.5 h-1, depending on particle size range |
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Additional control measures |
h-1 |
E.g. UV disinfection, personal HEPA air cleaner, etc. |
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Total first order loss rate |
h-1 |
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CONDITIONAL RESULT: Case in which instructor is infected, students are susceptible |
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Quanta emission rate (instructor) |
q h-1 |
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Mask efficiency for emission |
See readme sheet |
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Net emission rate |
q h-1 |
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Avg Quanta Concentration |
q m-3 |
Equation (4) in Miller et al. (2020) |
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Mask efficiency for intake |
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Quanta inhaled per student |
quanta |
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Probability of infection (1 student) |
Equation (1) in Miller et al. (2020). This assumes instructor was infected. See "Campus" sheet for more general case |
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Number of COVID cases arising |
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CONDITIONAL RESULT: Case in which student is infected, other students and instructor are susceptible |
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Quanta emission rate (student) |
h-1 |
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Mask efficiency for emission |
See readme sheet / Assume potentially different masks types for students and instructor |
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Net emission rate |
q h-1 |
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Avg Quanta Concentration |
q m-3 |
Equation (4) in Miller et al. (2020) |
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Mask efficiency for intake |
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Quanta inhaled per person |
quanta |
Using instructor breathing rate |
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Probability of infection (1 person) |
Equation (1) in Miller et al. (2020). This assumes 1 student was infected. See "Campus" sheet for more general case |
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Number of COVID cases arising |
This is for one lecture only, of the length specified above. For a whole semester, see "Campus" sheet |