F90A,B
F90
F90
F90
F90F90
F90
M923
Fig. 5. F90 Coanda air flow pattern.
Outdoor Air
DANCE FLOOR
STAGE | F90 |
LOW SMOKING LEVEL AT STAGE AND DANCE FLOOR. USE ONE F90.
HEAVY SMOKING LEVEL AT TABLES AND BAR.
USE THREE F90s.
F90
T
A
F90 B L
E
S
F90
BAR
M1528A
ASHRAE Standard
EXAMPLE: An office requires 20 cfm per person because the standard estimates some smoking, some copy machine operation, etc. The standard assumes outdoor air will be cleaned to less than 75 micrograms per cubic meter prior to introduction into the space. ASHRAE Standard
Fig. 4. F90 mounting considerations.
be provided as required.
Example 1. Sizing by Air Changes per Hour and Room Volume
An office measures 40 x 45 feet (12 x 14 meters) with a 15 foot (4.5 meter) ceiling. How many F90As should be installed?
Solution:
1. Find the room volume: 40 x 45 x 15 feet = 27,000 cubic feet, (12 x 14 x 4.5 meters = 756 cubic meters).
2. Assuming seven air changes per hour, with 27,000 cubic feet (756 cubic meters) volume, the graph below indicates three F90As are required.
3. Clean outdoor air is also required to replenish oxygen and dilute gaseous contaminants. 20 cfm per person is required for offices.
AIR
CHANGES
PER HOUR
| 25 |
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| 20 |
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BARS |
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| 15 |
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CAFETERIAS |
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BOWLINGLUNCHEONETTES |
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CENTERS |
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RESTAURANTS | 10 |
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| 10 |
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| 9 | |
PLACES OF |
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| 8 | |
ASSEMBLY |
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| 7 | |
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STORES | 5 |
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| 6 |
OFFICES |
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| 5 | |
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| 4 |
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| 3 |
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| 2 |
| 0 |
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| 1 |
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| 10,000 | 20,000 | 30,000 | 40,000 | 50,000 | 60,000 | 70,000 |
| [283] | [567] | [850] | [1133] | [1416] | [1700] | [1983] |
F90As REQUIRED
ROOM VOLUME IN CUBIC FEET AND [CUBIC METERS] | M1524 |
|
5 |