Honeywell F57A Original Manual page 5

BARS
CAFETERIAS
LUNCHEONETTES
BOWLING
CENTERS
RESTAURANTS
PLACES OF
ASSEMBLY
STORES
OFFICES
TO USE THE GRAPH:
1. EXTEND A HORIZONTAL LINE FROM THE DESIRED NUMBER OF AIR CHANGES PER HOUR, UNTIL IT INTERSECTS
WITH A VERTICAL LINE DRAWN UPWARD FROM THE NUMBER OF SQUARE FEET OF THE ROOM.
2. READ THE NUMBER OF UNITS REQUIRED AT THE INTERSECTION POINT.
Fig. 3. F57 sizing by air changes per hour and room area. In most cases, one F57B is equivalent to half an F57A because
the F57B airflow, although less than 50 percent of F57A airflow, is more effectively applied via several locations.
EXAMPLE 1:
Sizing by air changes per hour and room area (using the
graph in Fig. 3).
An office measures 40 x 45 ft (12 x 14m). How
many F57 air cleaners should be installed?
SOLUTION:
1. Find the floor area.
40 ft x 45 ft = 1800 ft
2. Assuming ten air changes per hour, with an 1800 ft
2
(168m ) area, the graph (Fig. 3) indicates a require-
ment for two F57A units, or four F57B units.
EXAMPLE 2:
Sizing by occupant load.
A cocktail lounge averages 75 occupants. How
many F57 air cleaners should be installed?
SOLUTION:
Number of F57s required =
ASHRAE Recommended Air Circulation/Min
F57 Capacity
1. ASHRAE recommended minimum air circulation is
3
35 cfm (1m /min) per person. For 75 people, the rec-
ommended air circulation would be:
75 people x 35 cfm (1m
3
(75m /min).
2. F57A capacity (HI setting) is 1030 ft3/min
3
(29m /min).
Number of F57As required =
3
2625 ft /min/1030 ft
or
F57B capacity (HI setting) is 485 cfm (14m
Number of F57Bs required =
3
2625 ft /min/485 ft
AIR
CHANGES
PER HOUR
25
20
15
10
5
0
537 1075
(50) (100)
AREA IN SQUARE FEET (SQUARE METERS)
2 2
(12m x 14m = 168m ).
3
/min) per person = 2625 cfm
3
/min = 2.5 or 3 units.
3
/min).
3
/min = 5 units.
F57A,B FLUSH-MOUNT COMMERCIAL ELECTRONIC AIR CLEANER
EXAMPLE 1
1610 2150 2690
(150) (200) (250)
EXAMPLE 3:
Sizing by air changes per hour and room volume.
A shop proprietor wants to use electronic air clean-
ing to remove high levels of smoke from the air. The
shop is 25 x 40 ft (8 x 12m) with a 15 ft (4.5m) ceil-
ing. How many F57 air cleaners will be required?
GUIDELINE: In the absence of other information, select the
correct number of F57 units to provide between 10 or 20
2
air changes per hour, depending on contaminant level. The
air cleaner should be located directly above or as close as
possible to the source of contamination.
SOLUTION:
Number of F57s required =
1. Calculate the volume of the room.
25 ft x 40 ft x 15 ft = 15,000 ft
(8m x 12m x 4.5m = 432m
2. Determine the volume of air to be circulated each
hour. Ten air changes per hour are used here on the
assumption that the intent is to reduce, but not com-
pletely eliminate, smoke.
3
15,000 ft
3
(432m x 10 air changes per hour = 4320m
Then determine the volume of air to be circulated
each minute.
150,000 ft
60 min/hr
3
4320 m /hr
60 min/hr
3. F57A capacity (HI setting) is 1030 ft
3
(29m /min).
Number of F57As required =
5
3230 3760
4300
(300) (350)
(400)
M1206B
Desired Air Circulation/Min
F57 Capacity
3
3
).
x 10 air changes per hour = 150,000 ft
3
/hr
3
= 2500 ft /min
3
= 72m /min
10
20
9 18
8 16
7
14
6 12
5 10
4 8
3 6
2
4
1 2
3
/hr
3
/hr).
3
/min
68-0083—07