Air Purifier Cost Comparison Template - C-R.xlsx

	A	B	C	D	E	F	G	I
1	Cost Factors	Smart Health S H13	Pair of Smart Health S H13	Smart Health Blast Mini H13	Smart Health Blast H13	Corsi- Rosenthal MERV13	Comments
2	Filtered Air Airflow (CFM):	305	610	820	1360	360	C-R Low 600 CFM *.60 capture efficiency
3	Noise Level - dB 1	52	52	49	43	58	C-R 58dB low, 67 High
4	Air Purifier Purchase Price	$189.95	$379.90	$599.00	$999.00	$85.00	Educational Discount
5	Replacement Filter Cost 2	$31.45	$62.90	$125.99	$179.99	$65.00	C-R 4 filters at $10+$5 for supplies	Rosenthal sells a 4-pack for $60, so that should be $15.
6	Filter life in school years	1.00	1.00	2.5	4.0	0.5	C-R assumes 3 mo filter life	https://www.texairfilters.com/4-filter-style-for-box-fan-and-merv-13-filters-air-cleaner/
7	Electrical usage on High: Watts	38	76	144	140	67	C-R 67W low, 98W high	https://filterbuy.com/air-filters/20x20x2/merv-13/
8								The price is similar on this website. The key is MERV13 for 20x20x2.
9	Air Purifier Purchase Cost per year	$94.98	$189.95	$299.50	$499.50	$20.00	Purchase Price / Depr. Years. C-R: 2 yrs	I changed CR filter lifespan to 6 months, which is still probably an underestimate given the test data:
10	Annual Filter Cost	$31.45	$62.90	$50.40	$45.00	$130.00	Filter cost / Filter Life	https://www.texairfilters.com/testing-the-efficiency-of-merv-13-corsi-rosenthal-boxes-in-use/
11	Annual Electrical Cost	$8.21	$16.42	$31.10	$30.24	$14.47	hrsdayskW Usage* Elec. Cost
12	Total Annual Cost	$134.63	$269.27	$381.00	$574.74	$164.47
13
19	Air Changes per Hour (ACH) in Room	2.3	4.6	6.2	10.2	2.7	(CFM60 minutes) /(ceiling heightroom size)
20
21	Cost per air change (ACH)	$58.86	$58.86	$61.95	$56.35	$60.92	This is what's needed to make the comparison apples to apples.
22	Cost per filtered air flow (CFM)	$0.44	$0.44	$0.46	$0.42	$0.46
23	Assumptions
25	Cost Analysis / Depreciation Period	2	I changed this to 2 years, which seems like a reasonable lifspan for a CR box fan.
26	Electrical Cost: kWhr	$0.12
27	Hours used per day, School days per Year	10	180
28	Room Size (sq. ft.), Height (Ft)	1000	8
29
30	Note: All Smart Health models use H13 HEPA filteration which has been proven effective against viruses, including COVID, in numerous peer reviewed studies. The C-R Box uses a much less effective MERV13 Filter. The Clean Air Flow Rate was discounted by 40% to account for the lower capture efficiency.
31
32	Note 1 : Perceived loudness doubles every 10 dB. 56dB is 32% louder than 52 dB. Values in the upper 50s and 60s likely too loud for classroom use so CFM at medium should be used. http://www.sengpielaudio.com/calculator-levelchange.htm
33
34
35
36	Total Annual Unit Cost stardardized to ACH of Smart Health S H13	$134.63	$134.63	$141.71	$128.89	$139.34	Total Annual Cost / ACH * Smart Health S ACH
37	% Increase in Standardized Annual Cost	100%	100%	105%	96%	103%	Compared to Smart Health S H13
38
39	Standardizes the total annual cost as if all units had the same capacity as the Smart Health S H13. Annual cost is lower for higher capacity units and vice versa.
40
41
42
43	https://www.medrxiv.org/content/10.1101/2022.01.09.22268972v1.full
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106