CIBSE_case

	A	B	C	D	E	F	G
1
2	Estimation of COVID-19 aerosol transmission: Case for Soccer Match (ONLY through air beyond close proximity, so will underestimate a lot)
3
4	This is a general spreadsheet applicable to any situation, under the assumptions of this model - See notes specific to this case (if applicable) at the very bottom
5	Important inputs as highlighted in orange - change these for your situation
6	Other, more specialized inputs are highlighted in yellow - change only for more advanced applications
7	Calculations are not highlighted - don't change these unless you are sure you know what you are doing
8	Results are in blue -- these are the numbers of interest for most people
9
10	Environmental Parameters
11
12		Value			Value in other units		Source / Comments
13	Length of room	600	ft		8.0	m	Can enter as ft or as m (once entered as m, changing in ft does not work)
14	Width of room	300	ft	=	8.0	m	Can enter as ft or as m (once entered as m, changing in ft does not work)
15		180000	sq ft		64	m2	Can overwrite the m2 one. If you want to enter sq ft, enter "=B15*0.305^2" in the m2 cell, where B15 is the cell w/ sq ft
16	Height	50	ft	=	2.4	m	Can enter as ft or as m (once entered as m, changing in ft does not work)
17	Volume				150	m3	Volume, calculated. (Can also enter directly, then changing dimensions does not work)
18
19	Pressure	0.95	atm				Used only for CO2 calculation
20	Temperature	20	C				Use web converter if needed for F --> C. Used for CO2 calculation, eventually for survival rate of virus
21	Relative Humidity	50	%				Not yet used, but may eventually be used for survival rate of virus
22	Background CO2 Outdoors	415	ppm				See readme
23
24	Duration of event	420	min		7.0	h	Value for your situation of interest
25
26	Number of repetitions of event	1	times				For e.g. multiple class meetings, multiple commutes in public transportation etc.
27
28	Ventilation w/ outside air	3.86	h-1				Value in h-1: Readme: Same as "air changes per hour". Value in L/s/per to compare to guidelines (e.g. ASHRAE 62.1)
29	Decay rate of the virus	0.62	h-1				See Readme, can estimate for a given T, RH, UV from DHS estimator
30	Deposition to surfaces	0.3	h-1				Buonnano et al. (2020), Miller et al. (2020). Could vary 0.24-1.5 h-1, depending on particle size range
31	Additional control measures	4.5	h-1				E.g. filtering of recirc. air, HEPA air cleaner, UV disinfection, etc. See FAQs, Readme for calc for portable HEPA filter
32	Total first order loss rate	9.28	h-1				Sum of all the first-order rates
33
34	Ventilation rate per person	10.9	L/s/person				This is the value of ventilation that really matters for disease transmission. Includes additional control measures
35
36	Parameters related to people and activity in the room
37
38	Total N people present	32					Value for your situation of interest
39	Infective people	1	person				Keep this at one unless you really want to study a different cases - see conditional and absolute results
40	Fraction of population inmune	0%					From vaccination or disease (seroprevalence reports), will depend on each location and time, see Readme
41	Susceptible people	31	people				Value for your situation of interest
42
43	Density (area / person) in room	21	sq ft / person
44	Density (people / area) in room	0.50	persons / m2
45	Density (volume / person) in room	4.7	m3 / person
46
47	Breathing rate (susceptibles)	0.72	m3 / h				See Readme sheet - varies a lot with activity level
48	Relative breathing rate factor	2.50					Ratio between the actual and base breathing rates
49	CO2 emission rate (1 person)	0.0061	L/s (@ 273 K and 1 atm)				From tables in Readme page. This does not affect infection calculation, only use of CO2 as indicator, could ignore
50	CO2 emission rate (all persons)	0.2205	L/s (@ at actual P & T of room)				Previous, multiplied by number of people, and applying ideal gas law to convert to ambient P & T
51
52	Basic quanta exhalation rate	18.6	infectious doses (quanta) h-1				See Readme sheet
53	Q. enhancement due to variants	2.5	Dimensionless				1 for the original variant, 2 for Delta, 2.5 for Omicron. See Readme file.
54	Q enhancement due to vocal. & act.	1.0	Dimensionless (ratio to breathing)				Relative increase in emission rate due to vocalization and physical activity (compared to breathing)
55	Quanta exhalation rate (infected)	46.5	infectious doses (quanta) h-1				This is a result. Change the previous row if you want to experiment with the quanta emission rate
56
57	Exhalation mask efficiency	0%	No masks as I understand is the case in the UK				0 if infective person is not wearing a mask. See Readme sheet
58	Fraction of people w/ masks	0%					Value for your situation. It is applied to everybody for both emission & inhalation. Modify formulas manually if needed
59	Inhalation mask efficiency	0%					See Readme sheet
60
61	Parameters related to the COVID-19 disease
62
63	Probability of being infective	0.100%					Very important parameter, specific for each region and time period. For ABSOLUTE results (prob. given prevalence of disease in the population). See Readme sheet
64
65	Hospitalization rate	10%					From news reports. Varies strongly with age and risk factors
66	Death rate	1%					From news reports. Varies strongly with age and risk factors (1% typical - Higher for older / at risk people)
67
68	CONDITIONAL result for ONE EVENT: we assume the number of infected people above, and get the results under that assumption
69	More appropriate to simulate known outbreaks (e.g. choir, restaurant etc.), and an worst-case scenario for regular events (if one is unlucky enough to have infective people in attendance of a given event)
70
71	Net emission rate	46.5	infectious doses (quanta) h-1				Includes the number of infective people present
72	Avg Quanta Concentration	0.03	infectious doses (quanta) m-3				Analytical solution of the box model. Equation (4) in Miller et al. (2020)
73	Quanta inhaled per person	0.17	infectious doses (quanta)
74
75	Conditional Results for A GIVEN PERSON & ONE EVENT (assuming number of infected above, typically 1)
76	Probability of infection (1 person)	15.239%					Applying Wells-Riley infection model to the amount of infectious doses inhaled. Equation (1) in Miller et al. (2020)
77	Prob. of hospitalization (1 person)	1.5%
78	Prob. of death (1 person)	0.2%
79	Ratio to risk of car travel death	2540	times larger risk				See FAQs for rough estimate of death traveling by car on a given day
80
81	Conditional Results for ALL ATTENDEES & ONE EVENT (assuming number of infected above, typically 1)
82	Number of COVID cases arising	4.72					Number of people. Multiplies probability of one person, times the number of susceptible people present
83	N of hospitalizations arising	0.47					Number of people
84	N of deaths arising	0.05					Number of people
85
86	Airborne Infection Risk Parameters (From Peng et al., 2022)
87	Infection Risk Parameter (H)	0.38	h2 person / m3				Indicator of risk in terms of OUTBREAK SIZE. Low risk: H<0.05; Med: H<0.5; High: H>0.5; From Peng et al. (2022)
88	Relative Inf. risk Parameter (Hr)	0.012	h2 / m3				Indicator of risk in terms of ATTACK RATE. Low risk: Hr< 0.001; Med< 0.01; High>0.01 From Peng et al. (2022)
89
90	Results for CO2 as an indicator of risk (not needed for infection estimation, can ignore for simplicity)
91	Avg CO2 mixing ratio	1717	ppm (including 400 ppm background)				Analytical solution of the box model. Equation (4) in Miller et al. (2020). See FAQ page for differences w/ quanta calc
92	Avg CO2 concentration	2.29	g m-3 (excluding 400 ppm background)				Conversion from Atmos. Chem. Cheat Sheet, plus ideal gas law
93	Exhaled CO2 re-inhaled per person	11.53	grams (excluding 400 ppm background)				This parameter is the most analogous to risk. See FAQ page for limitations
94	Exhaled CO2 re-inhaled per person	9217.91	ppm * h (maybe easier units, excludes 400 ppm background)				This parameter is the most analogous to risk. See FAQ page for limitations
95	Exhaled CO2 re-inhaled per person	0.9218	%CO2 * h (same as above, different unit, for use next)
96	Ratio of prob of infection to Ex_CO2	0.1653	% chance of infection for 1 person per %CO2 * h inhaled
97	CO2 to inhale 1 hr for 1% infect.	1013	ppm				This is another metric of risk
98
99	ABSOLUTE result for ONE EVENT: we use the prevalence of the disease in the community to estimate how many infected people may be present in our event, and calculate results based on that
100	More appropriate for general risk estimation, e.g. in a college classroom, indoor gathering etc., where often infective people will not be present