Air Cleaner Manual

F57A,B FLUSH-MOUNTED COMMERCIAL ELECTRONIC AIR CLEANER
68-0083-9 Revised 11-08
5
15,000 ft
3
x 10 air changes per hour = 150,000 ft
3
/
hr
(432m
3
x 10 air changes per hour = 4320m
3
/hr).
Then determine the volume of air to be circulated
each minute.
150,000 ft
3
/hr
60 min/hr = 2500 ft
3
/min
4320 m
3
/hr
60 min/hr = 72m
3
/min
3. F57A capacity (HI setting) is 1030 ft
3
/min
(29m
3
/min).
Number of F57As required =
2500 ft
3
/min 72m
3
/min
1030 ft
3
/min 29m
3
/min = 2.4 or 3 units.
or
F57B capacity (HI setting) is 485 cfm (14m
3
/min).
Number of F57Bs required =
2500 ft
3
/min 72m
3
/min
485 ft
3
/min 14m
3
/min = 5 units.
Regardless of the method used for calculation, the physical
limitations of the space to be cleaned can influence the
number of electronic air cleaners required. For ambient air
cleaning, it is essential to establish a uniform airflow pattern
throughout the entire space. Fewer electronic air cleaners can
be installed because of a lack of mounting space. More units
may be required due to an oddly-shaped room that does not
lend itself to an even airflow.
If any questions should arise concerning size, consult your
distributor or local Honeywell Commercial Air Cleaner
Distributor.
Choose Location
The F57 is mounted horizontally, and can be used in almost
any air cleaning application that has a suspended ceiling. For
the most efficient operation, place the F57 as close as
possible to the contaminant source.
When placing the F57, be sure that the clean air discharge
enhances the airflow patterns of the area to be cleaned. For
example, do not place the air cleaner so its discharge disrupts
the flow from the central air handling system supply registers.
The shape of the room, location of central air conditioning
diffusers and returns, architectural features, and ceiling
obstruction will affect optimum F57 location in the ceiling.
For partial dilution of odor and gaseous contaminant, some
F57 discharge air can be bled off into the area above the
suspended ceiling, or a run of 12 ft (3.7m) or less of 5 in.
(127 mm) round duct can be vented outdoors or to an exhaust
duct that is always at negative pressure.
Determine if the air vent of the unit must be ducted to the
return air plenum (as some local building codes require).
For duct connection, make sure the access panel to the vent
is removed so a 5 in. (127 mm) diameter duct can be
connected to the collar (collar is field supplied).
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
(12m x 14m = 168m
2
).
2. Assuming ten air changes per hour, with an 1800
ft
2
(168m
2
) area, the graph (Fig. 3) indicates a
requirement 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 35 cfm (1m
3
/min) per person. For 75 people,
the recommended air circulation would be: 75
people x 35 cfm (1m
3
/min) per person = 2625 cfm
(75m
3
/min).
2. F57A capacity (HI setting) is 1030 ft
3
/min
(29m
3
/min).
Number of F57As required = 2625 ft
3
/min/1030
ft
3
/min = 2.5 or 3 units.
or
F57B capacity (HI setting) is 485 cfm (14m
3
/min).
Number of F57Bs required = 2625 ft
3
/min/485 ft
3
/
min = 5 units.
EXAMPLE 3: Sizing by air changes per hour and room
volume.
A shop proprietor wants to use electronic air
cleaning 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) ceiling. 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 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 =
Desired Air Circulation/Min
F57 Capacity
1. Calculate the volume of the room.
25 ft x 40 ft x 15 ft = 15,000 ft
3
(8m x 12m x 4.5m = 432m
3
).
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 completely eliminate, smoke.