|
CALCULATING FILTER LIFE
WORK SHEET
| |
|
Dust Holding Capacity in Grams |
|
Filter Life |
= |
---------------------------------------------------------------------------------------------- |
| |
|
Prefilter |
x |
ADC |
x |
Constant |
x |
AFC |
x |
Ave. Arres. |
x |
60 [min.] |
| |
|
Factor |
|
|
|
0.065 |
|
|
|
% |
|
[per hr.] |
WHERE:
|
Filter Life |
= |
Fan Hours |
|
Prefilter Factor |
= |
Prefilter performance efficiency |
|
Average Dust Concentration |
= |
Grains per 1000 cubic feet |
|
Constant |
= |
Factor to convert grains to grams |
|
Air Flow Capacity |
= |
CFM [in thousands] |
|
Filter Arrestance |
= |
ASHRAE Arrestance % Value |
|
Annual Average Airborne |
= |
Consult EPA Chart for U.S. |
|
Dust Concentration in Grains per 1000 cubic feet |
= |
Consult EPA Chart for U.S.
Metropolitan Areas |
| |
|
[grams] |
|
Filter Life |
= |
---------------------------------------------------------------------------------------------- |
| |
|
.18 |
x |
0. |
x |
0.065 |
x |
2.0 |
x |
. % |
x |
60 |
| |
|
[grams] |
|
|
|
|
Filter Life |
= |
------------------------------------------------------- |
Filter Life |
= |
Fan Hours |
Fan Hours = 24 hrs.per day: 365 days per yr. = 8760 fan hrs. per yr. or 730
fan hrs. per month.
Fan Hours = 12 hrs.per day: 365 days per yr. = 4380 fan hrs. per yr. or 365
fan hrs. per month.
|
Estimated |
|
[fan hours] |
|
|
|
Filter Life |
= |
-------------------------------------------- |
= |
Months |
|
In Months |
|
[fan hours per month] |
|
|
NOTE: The fan hours of filter life determined by the calculation provide a
general rule of thumb estimate. Due to variables in situations, circumstances
and conditions, filter life is difficult to predict accurately. We do not use
this formula to Guarantee or otherwise imply that a customer can
expect to achieve the life calculated by this formula. Filter life may be longer
or shorter, depending on the variables and conditions.
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