ASTM F2975-12(2022)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2975 − 12 (Reapproved 2022) An American National Standard
Standard Test Method for
Measuring the Field Performance of Commercial Kitchen
Ventilation Systems
This standard is issued under the fixed designation F2975; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope mance of Commercial Kitchen Exhaust Ventilation Sys-
tems
1.1 This test method can be used to measure and validate
2.2 Other Standards:
successful design, installation and commissioning of commer-
ANSI/ASHRAE Standard 111-2008 Measurement, Testing,
cial kitchen HVAC and makeup air systems for specific
Adjusting and Balancing of Building HVAC Systems
installations.
ANSI/ASHRAE Standard 154 Ventilation for Commercial
1.2 This test method field evaluates commercial kitchen
Cooking Operations
ventilation system airflows and pressures.
Testing, Adjusting and Balancing, Chapter 37 2007 HVAC
1.3 This test method field evaluates visual hood capture and
Applications Handbook
containment performance.
Kitchen Ventilation, Chapter 31 2007 HVAC Applications
Handbook
1.4 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are for informa-
3. Terminology
tion only.
3.1 Definitions:
1.5 The data generated is specific to the field conditions as
3.1.1 airflow rate—volumetric flow rate of air in units of
installed.
3 3
ft /min (cfm) or m /s. When adjusted for standard air density
1.6 This test method may involve hazardous materials,
the flow rate is designated by scfm.
gasses (for example, CO) operations, and equipment. This
3.1.2 appliance—cooking device used in kitchen and pow-
standard does not purport to address all of the safety concerns,
ered by gas, and/or electricity and/or solid fuel.
if any, associated with its use. It is the responsibility of the user
3.1.3 barometric pressure—absolute pressure of the air
of this standard to establish appropriate safety, health, and
measured by a barometer or absolute pressure measuring
environmental practices and determine the applicability of
device.
regulatory limitations prior to use.
1.7 This international standard was developed in accor-
3.1.4 captureandcontainment(C&C)—theabilityofahood
dance with internationally recognized principles on standard-
or other removal device to capture and contain all effluent
ization established in the Decision on Principles for the
generated by the appliances or processes during normal opera-
Development of International Standards, Guides and Recom-
tion.
mendations issued by the World Trade Organization Technical
3.1.4.1 Discussion—For the purpose of this test method
Barriers to Trade (TBT) Committee.
effluent may be simulated as defined in this test method.
3.1.4.2 Discussion—Successful C&C shall be demonstrated
2. Referenced Documents
along the entire perimeter of the hood or removal device.
3.1.4.3 Discussion—Successful C&C may include rising
2.1 ASTM Standards:
effluent that when below the leading edge of the hood may
F1704 Test Method for Capture and Containment Perfor-
extend out no more than 3 in. vertically beyond the leading
edge of the hood and is completely recovered before reaching
This test method is under the jurisdiction of ASTM Committee F26 on Food
the leading edge of the hood or removal device and once inside
Service Equipment and is the direct responsibility of Subcommittee F26.07 on
the hood is completely contained. F1704
Commercial Kitchen Ventilation.
Current edition approved May 1, 2022. Published June 2022. Originally
approved in 2012. Last previous edition approved in 2017 as F2975 – 12 (2017).
DOI: 10.1520/F2975-12R22. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from American Society of Heating, Refrigerating, and Air-
Standards volume information, refer to the standard’s Document Summary page on Conditioning Engineers, Inc. (ASHRAE), 1791 Tullie Circle, NE, Atlanta, GA
the ASTM website. 30329, http://www.ashrae.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2975 − 12 (2022)
3.1.4.4 Discussion—For backshelf or passover style hoods difference between the total pressure sensed by the central tube
effluent shall not rise more than 3 in. above the exterior leading and the static pressure sensed by the outer tube.
edge of the hood and shall not extend more than 3 in. beyond
3.1.15 replacement air—outdoor air that is used to replace
the open front or sides of the cooking surface and shall be
air removed from a building through an exhaust system.
completely contained once reaching the hood.
Replacement air may be derived from one or more of the
following: Kitchen Supply, Makeup Air and/or Transfer Air.
3.1.5 differential pressure gauge—instrument that measures
However, the ultimate source of all replacement air is outdoor
pressure difference between the two inlet ports. This can be a
air.
mechanical type such as a Bourdon gauge with an indicator on
a dial face or an electronic type with a digital readout.
3.1.15.1 kitchen supply—air entering a space that contains
hoods and originates from an air-handling device that serves
3.1.6 dry bulb temperature—sensible temperature of air as
both purposes of supplying replacement air as well as space
measured by a shielded thermometer or an electronic tempera-
conditioning. Supply air is generally filtered, fan-forced, and
ture measuring device.
either heated and/or cooled and/or humidified and/ or dehu-
3.1.7 effluent—emissions from cooking, dishwasher or other
midified as necessary to maintain specified space temperature
ventilated processes such as convective hot air, steam, vapor,
and/or humidity conditions.
products of combustion, smoke and/or particulate matter.
3.1.15.2 makeup air (dedicated replacement air)—outdoor
3.1.8 exhaust fan—also called power roof ventilator or
air supplied directly to a compensating hood or to supply air
centrifugal blower. A fan used to exhaust cooking effluent
deviceslocatedintheimmediatevicinityofthehoodtoreplace
including, grease, smoke, steam, heat, and/or vapor collected
air being exhausted through the hood. Makeup air is generally
by a hood. The majority of these fans have a centrifugal fan
filtered and fan-forced, and it may be heated and/or cooled
wheel.
depending on the requirements of the application. Makeup air
3.1.9 exhaust hood—a device designed to capture and con- may be delivered through outlets integral to the exhaust hood
tain cooking effluent including, grease, smoke, steam, hot air,
or through outlets in the same room that are typically in the
and vapor. immediate vicinity of the hood.
3.1.10 flow hood—an instrument that measures air flow rate 3.1.15.3 transfer air—outdoor that has been conditioned to
maintain comfort of and ventilate a space adjacent to the space
using a pyramid shaped hood that is used to contain the air to
be measured and is connected to a velocity pressure measuring in which the hood is located. Movement of this air may be
caused by pressure differential between spaces, that are sepa-
devicepositionedattheoutletendofthehood.Acompensating
baffle may be installed so that measurements with the baffle rated by adequately sized openings, or by fans and or grills
connected by ductwork above ceilings and or through walls,
open and closed can be used to estimate the air flow rate
through the device being measured when the pressure drop andshallbeusedtosupplementthecomfortconditioningofthe
imposed by the flow hood is eliminated. space in which the hood is located and to replace air exhausted
through the hood.
3.1.11 hood overhang—the horizontal distance the lower
3.1.16 rotating vane anemometer (RVA)—an instrument that
edge of the hood extends beyond the outer horizontal edge of
measuresairvelocityusinganelectronicpickuptomeasurethe
the cooking surface or outer perimeter of the appliance body.
rotating speed of the vane or propeller. The body of the
3.1.11.1 hood setback—the horizontal distance between the
anemometer is positioned perpendicular to the expected direc-
lower front edge of the hood and the front of the edge of the
tion of the air velocity.
cooking surface or outer perimeter of the cooking appliance.
3.1.17 smoke emitter—device that produces smoke particles
Setback is used for hood styles such as backshelf and/or
from a chemical reaction. The rate of smoke production is
passover that do not fully cover the entire cooking surface or
sufficient to be followed with the naked eye.
appliance.
3.1.18 standard air—air with a density of 0.075 lb/ft .
3.1.12 hot-film anemometer—an instrument for measuring
3.1.19 velocity grid—a velocity measuring device that con-
air velocity at a single point.The instrument measures velocity
past a heated sensor and requires calibration to correlate heat sists of an array of holes on both sides of a matrix. The holes
serveaspressuretapsontheupstreamanddownstreamsidesof
loss to air velocity.
the device. When connected to a differential pressure monitor
3.1.13 humidity measuring device—an instrument for mea-
and calibrated, it will provide the average air velocity across
suring the amount of moisture in the air. The instrument shall
the matrix.
provide the moisture level as either a) relative humidity, b) wet
bulb temperature or c) and/or dew point temperature.
4. Summary of Test Method
3.1.14 pitot tube—a double walled probe with a 90 degree
4.1 All systems that supply comfort conditioning, replace-
bend near the measuring end. The measuring end of the probe
ment air and/or supply air, makeup air, exhaust systems and
is oriented toward the oncoming air flow. The center opening,
cooking appliances in the kitchen shall be installed and
facing the oncoming airstream senses total pressure. Small
operational.
holes located around the circumference of the outer tube sense
static pressure. When connected to a differential pressure 4.2 The general ventilation system or systems for any
instrument the velocity pressure of the air is y measured as the portion or portions of the building that are adjacent to the
F2975 − 12 (2022)
kitchen and/or supply transfer air to the kitchen shall be the air pressure in the kitchen is more than 0.200 in. water less
installed and operation during the test procedure and shall than the air pressure in adjacent spaces, the makeup air flow
maintain the design air pressure in adjacent spaces and shall rate or supply air flow rate to the kitchen must be increased
supply the necessary transfer air. until the pressure differential is reduced to between 0.050 and
0.200 in. water.
4.3 The airflow rates for HVAC, Replacement Air and
kitchen exhaust shall be those specified.
5. Significance and Use
4.4 All ventilation systems associated with the kitchen and
5.1 Successful kitchen exhaust hood performance requires
spaces adjacent to the kitchen shall be turned on and operated
the complete capture and containment of the effluent plume
as under full load cooking conditions.
along the hood’s entire perimeter.Any effluent leakage moving
4.5 The flow rate of air exhausted through the kitchen hood
beyond 3 in. from the hood face will be deemed as having
shall be measured and computed using the apparatus and
escaped from the hood, even if it may appear to be have been
methods defined in this test method. Results shall be adjusted
drawn back into the hood. If effluent spills from the hood, hot
and reported in standard cubic feet per minute (scfm).
and greasy kitchens may be the result and the cause of the
4.6 Whenthecomputedairflowrateisnotwithin5%ofthe
performance failure needs to be determined and corrected.
specified value from 4.3, adjustments, such as changing fan
Oftentimes, the exhaust flow rate needs to be increased to
speedshallbemadeuntilthemeasuredcomputedairflowrates
achieve proper hood performance for particular field condi-
are within5%of specified values.
tions. As a result, the supply air to the kitchen will need to be
increased to maintain the air balance. However, drafty room
4.7 The total flow rate of air supplied to the kitchen shall be
conditions due to incorrectly placed supply diffusers, cross
determined by measuring the flow rate through each supply
drafts from windows and doors, return and supply at opposite
diffuser and makeup air unit and reporting the corresponding
ends of the kitchen, etc. could also severely degrade hood
air flow rates as standard cubic feet per minute (scfm). The
performance. Incorrectly designed supply systems may not be
total amount of air supplied to the kitchen shall be the sum of
corrected by increasing the exhaust rate and could be corrected
the measurements from the individual units.
in a much more efficient and economical manner, such as by
4.8 When the measured air flow rate through any of the
replacing a 4-way diffuser with a 3-way diffuser directed away
supply or makeup air units is less than 95 % of the specified
from the hood. Likewise, if the plume is strongly captured, the
value from 4.3, adjustments shall be made such as increasing
hood may be over-exhausting and reducing the exhaust rate
fanspeedand/oradjustingdamperpositionsuntilthecomputed
could be considered, along with a corresponding reduction of
and specified air flow rates are within 5 % for each supply and
room supply air to maintain the building’s air balance.
makeup air unit.
5.2 An appropriate airflow balance ensures adequate re-
4.9 With the supply air, makeup air, and exhaust air flow
placement air for the necessary exhaust conditions and allows
rates set to within5%of their design values, the ability of all
the desired air pressure distribution to be maintained.
exhaust hoods to capture and contain cooking effluent shall be
evaluated. All cooking appliances shall be turned on to idle 5.3 Negative air pressure in the kitchen with respect to the
conditions and allowed to warm up for one hour. Smoke adjacent indoor spaces ensures that the air flow is from these
emitters shall be used to ensure that the smoke enters all the spaces into the kitchen so that odors and cooking effluent are
hoods without spillage around the entire perimeter of each contained within the kitchen. However, too great a pressure
exhaust hood. imbalance will severely degrade hood performance by creating
a wind tunnel effect. Negative air pressure in the dining area
4.10 If spillage occurs, the exhaust air flow rate in the hood
with respect to the outside is usually an indication that the
must be increased, or the replacement air redirected, and the
supply air rate is inadequate and as a result the exhaust air
test repeated until no spillage is observed. The increase in
system is not performing as specified.
exhaust flow rate is usually accomplished by increasing the fan
speed.
6. Apparatus
4.11 The differential static pressure shall be measured be-
6.1 Velocity Grid, for measuring average velocity across the
tween the kitchen and adjacent areas in the same building such
face of a grease filter or extractor mounted in an exhaust hood
as the dining area and dry storage areas, and the kitchen and
and makeup air devices with a range of 25 to 2500 fpm and an
outdoors.
uncertainty of 63 % of reading.
4.12 When the kitchen static pressure is within 0.02–0.05 6
6.2 Barometer—Direct Reading or Electronic, for measur-
0.005 of the static pressure of the dining area or any adjacent
ing barometric or atmospheric pressure which is required to
occupied area in the building, at least one kitchen exhaust
correct airflow readings to standard air density conditions. The
system shall be adjusted to exhaust a larger amount of air until
instrument may be either a Bourdon tube type or an electronic
the pressure in the kitchen is a minimum of 0.005 in. water less
type with accuracy of 61 % of full scale.
than the surrounding areas.
4.13 When the total exhaust air flow rate from the kitchen 6.3 Differential Pressure Gauge, for measuring the pressure
has been increased more than 10 % above the design value to difference across filter banks, supply air diffusers, makeup air
provide adequate capture and containment of the effluent, and devices or between rooms and for reading the velocity pressure
F2975 − 12 (2022)
when using Pitot static tubes for velocity measurement. Re- 9.1.1 Choose a day with no wind or only very light
quired instrument range is 0 to 1.0 in. water with an accuracy occasional winds. (Continuous high winds and gusty winds
minimum of 61 % of full scale. create pressure imbalances that are difficult to analyze by these
methods, and will generally result in a building with too much
6.4 Flow Hood, a pyramid-shaped hood connected to a
outside air).
differential pressure measuring device that may be used to
9.1.2 Ensure that doors to the outside remain closed during
collect all the air from a terminal and guide it over a flow
the tests so that the makeup and exhaust air flow rates and
measuring system to provide the total air flow rate in cfm.
internal building pressure are controlled by the mechanical
Required range is 25–2500 cfm with accuracy of 63%of
ventilation systems.
reading.
9.1.3 The entire replacement air and exhaust systems shall
6.5 Hot-Film Anemometer, for measuring air velocity at a
be fully operational and ready for balancing.
single point. Typical range is 10 to 8000 fpm (0.05 to 40 m/s).
9.2 Duct Systems:
Instrument accuracy is 63 % of full scale.
9.2.1 Preliminary Checks:
6.6 Pitot-Static Tube, for measuring air velocity in duct-
9.2.1.1 Inspect the entire supply air duct system from each
work.
makeup air unit to the last air supply terminal to make certain
6.7 Humidity Measuring Device, for measuring the amount
the installation matches the drawing specifications.
of moisture in the air which is necessary to convert the
9.2.1.2 Inspect the entire exhaust duct system from each
measured air flow rate into standard air flow rate. The
exhaust hood to the exhaust fan to make certain the installation
instrument shall provide the moisture level as either a) relative
matches the drawing specifications.
humidity, b) wet bulb temperature or c) dew point temperature.
9.2.1.3 Verify the ductwork is complete and installed cor-
Relative humidity instruments shall have a range of 20 to 90 %
rectly. There shall be no openings in the ductwork, no missing
at 70°F with an accuracy of 63 %. Wet bulb and dew point
endcaps,andallaccessdoorsshallbeclosedandsecuredtight.
instruments shall have a range of 32 to 100°F with an accuracy
9.3 Hood Filters:
of 60.1°F.
9.3.1 The correct size and type of filters shall be installed in
6.8 Rotating-Vane Anemometer—4 in., for measuring the
all exhaust hoods. When permanent filters are used, they shall
velocity distribution near an air discharge or exhaust opening.
be the correct size and type per the drawing specifications.
Lower end of velocity range is 200 fpm and accuracy is 62%
9.3.2 The filters shall be clean from grease and debris.
of reading.
9.3.3 The filter frames shall be properly installed and
6.9 Rotating-Vane Anemometer—2 ⁄4 in., for measuring the
airtight.
velocity distribution near an air discharge or exhaust opening.
9.4 Appliance Placement:
Lower end of velocity range is 200 fpm and accuracy is 62%
9.4.1 Appliances Under Canopy Hoods:
of reading.
9.4.1.1 All appliances shall be in their correct positions and
6.10 Ammeter, True RMS, Clamp-On, for measuring current
held in place with the wheels locked. The rear of each
draw of fan motors. Accuracy 1.5 % of reading, resolution 10
appliance shall be as close as possible to the rear wall of the
mA.
canopy hood or center of a back to back island hood arrange-
6.11 Tachometer, optical or contact type for measuring
ment.
rotational speed of motor, fan, or pulley. Accuracy 0.05 % of
9.4.1.2 All gas-fired appliances shall be connected to a gas
reading, resolution 0.1 rpm.
line with the required capacity.
9.4.1.3 All electric appliances shall be connected to an
6.12 Thermometer, Digital Electronic, for measuring air dry
electrical supply with the required capacity.
bulb temperature that consists of a thermocouple, thermistor or
9.4.2 Grills and Fryers under Backshelf Hoods:
resistance temperature device (RTD) connected to a digital
readout. Typical range is +14 to +248°F (–10 to 120°C).
9.4.2.1 Each appliance shall be tightly seated into the hood
Instrument accuracy shall be 60.5°F (0.3°C). and held in place with a locking bar, capping piece or wheel
locks.
7. Reagents and Materials
9.4.2.2 The rear of each appliance shall be tightly sealed
againsttherearwallofthehoodsothereisnoairbypassatthis
7.1 Smoke emitters (creating less than 400 cfm) for visual-
location.
izing the air flow during the capture and containment tests.
9.4.2.3 If the hood is designed with flue bypass, the flue
8. Sampling
restrictors shall be properly set for gas heated equipment and
flue passage shall be completely sealed off for electric heated
8.1 Ventilation System—The fully installed and operational
equipment.
HVAC system associated with a commercial kitchen and the
surrounding spaces in the building shall be selected for air
10. Procedure
balancing.
10.1 General:
9. Preparation of Apparatus
10.1.1 Allexteriordoorsfromoutsidetothekitchenshallbe
9.1 General: closed.All doors between the kitchen and the adjacent interior
F2975 − 12 (2022)
spaces shall be closed. Exceptions are pass-through openings 10.1.11 Once the facility is operational; the performance of
and walkways that are normally open. the ventilation system should be checked to verify that the
design is adequate for the actual operation, particularly at
10.1.2 The barometric pressure, air dry bulb temperature
maximum cooking and at outdoor environmental extremes.
and relative humidity in the kitchen shall be measured and
Any necessary changes should be made, and all the records
recorded as initial values when the testing begins. Ambient
should be updated to show the changes. Rechecking the air
weather conditions for the day shall be recorded including
balance should not be necessary more than once every 2 years
ambient dry bulb temperature, wind speed and direction, and
unless significant changes are made in facility operation. If
relative humidity. Ambient conditions may be obtained from
there are major changes, such as a new type of cooking
the nearest NOAA weather recording station.
equipment or added or deleted exhaust connections, the system
10.1.3 Allkitchenexhaustfansshallbeturnedontoachieve
should be modified accordingly and rebalanced.
design exhaust air flow rates necessary for full load cooking.
10.2 ExhaustAirFlowRateMeasurementsThroughKitchen
The cooking appliances shall be turned at hot ready-to-cooking
condition for the air flow balance measurements. The exhaust Exhaust Hoods:
air flow rates through all exhaust hoods shall be measured, 10.2.1 The total air flow rate through each exhaust hood
compared with design values and adjusted as necessary until
shall be determined using one of the following methods with
each is within 65 % of the design value. the cooking appliances turned at hot ready-to-cooking condi-
tion.
10.1.4 The replacement air flow rate, whether part of
10.2.1.1 Whenaspecificairflowratemeasurementprotocol
combined HVAC units or separate makeup air units, shall be
is specified by the hood or filter manufacturer, the protocol
set to 65 % of the design value through each outlet, with the
developed by the manufacturer shall be followed.
approximate correct settings on the outside air flow rate. Then,
10.2.1.2 When the filters under test have no protocol from
the correct outside and return air flow rates shall be set
proportionately for each unit, as applicable. the manufacturer but has a protocol specified in this document,
the method of test specified in this document shall be followed.
10.1.5 Outside air shall be set with all fans (exhaust and
10.2.1.3 When the filters under test have no protocol from
supply) operating. The pressure difference between inside and
the manufacturer and do not have a protocol specified in this
outside shall be checked to see that (1) the non-kitchen zones
document, or one or more obstructions prevents proper use of
of the building are at a positive pressure compared to outside
face velocity measuring instruments, a duct traverse method
and (2) the kitchen zone pressure is 0.050 to 0.200 in. of water
shall be used to determine the total air flow rate through an
negative compared to the surrounding zones and negative or
exhaust hood using a Pitot-static tube. The Log-Tchebycheff
neutral compared to outside.
rule shall be used for rectangular ducts and the Log-linear rule
10.1.6 For applications with modulating exhaust, every step
for circular ducts as specified in ANSI/ASHRAE Standard
of exhaust and replacement shall be shut off, one step at a time.
111-2008, ”Measurement, testing, adjusting and balancing of
Each combination of operation shall be rechecked to be sure
building HVAC systems”.
that the design pressures and flows are maintained within each
10.2.2 Hoods with Baffle Filters:
zone and between zones. This requires that the replacement
10.2.2.1 Thesemeasurementsarelimitedtotheuseofa4in.
airflow rate compensate automatically with each increment of
rotating vane anemometer with its body parallel to and
exhaust. It may require some adjustments in controls or in
positioned flush to the filter face.
damper linkage settings to get the correct proportional re-
sponse.
10.1.7 Capture and containment of the cooking effluent
shall be demonstrated for each exhaust hood with the appli-
ances at idling/ready to cook condition using a smoke emitter.
10.1.8 The air dry bulb temperature, relative humidity, and
barometric pressure within the kitchen shall be recorded at the
end of the day as final values.
10.1.9 When the above steps are complete, the system is
properly integrated and balanced. At this time, all fan speeds
and damper settings (at all modes of operation) shall be
permanently marked on the equipment and in the test and
balance report. The air balance records of exhaust, supply,
return, fresh air, and individual register airflows must be
completed. These records shall be kept by the food service
facility for future reference.
10.1.10 For new facilities, after two or three days in
operation(nolongerthanaweekandusuallybeforethefacility
opens), all belts in the system should be checked and read-
justed because new belts wear in quickly and could begin
slipping. FIG. 1 Baffle Filter
F2975 − 12 (2022)
10.2.2.2 Each filter in an exhaust hood must be evaluated
separately and the flow rate through each filter added to
determine the total airflow rate through the entire exhaust
hood.
10.2.2.3 The dimensions of the open portion, height and
width (H and W), of each filter shall be measured with an
accuracy of 6 ⁄4 inch and the results recorded.
10.2.2.4 The center of the rotating vane anemometer shall
traverse the entire face of the filter in a back-and forth motion.
The minimum time to traverse the entire filter face shall be 30
s. An example is shown in Fig. 2. Average velocity readings
shall be measured and recorded at each location.
10.2.2.5 Thebodyoftheinstrumentshallremainflushtothe
exterior surface of the filters, and be kept parallel to it.
FIG. 3 Cyclone Filter
10.2.2.6 Airflow through the instrument shall not be ob-
structed by the operator’s hand or fingers.
10.2.2.7 The velocity measurements in a filter bank shall be
measured beginning with the filter at one end of the filter bank
10.2.3.8 The velocity measurements in a filter bank shall be
and ending with the filter at the opposite end.
measured beginning with the filter at one end of the filter bank
10.2.2.8 The procedure described above shall be repeated
and ending with the filter at the opposite end.
twice more to obtain the average velocity for all three readings
10.2.3.9 The procedure described above shall be repeated
at each location in feet per minute (FPM).
twice more to obtain the average velocity for all three readings
10.2.3 Hoods with Cyclone Filters:
at each measurement position in feet per minute (FPM).
10.2.3.1 These measurements are limited to the use of a
10.2.4 Hoods with Slot Filters (Cartridge—Removable or
2 ⁄4-in. diameter rotating vane anemometer with its body
Stationary):
parallel to and positioned 2 in. from the filter face.
10.2.4.1 Thesemeasurementsarelimitedtotheuseofa2.75
10.2.3.2 Each filter in an exhaust hood must be evaluated
in. rotating vane anemometer positioned at the slot opening.
separately and the flow rate through each filter added together
Eachfilterinanexhausthoodmustbeevaluatedseparatelyand
to determine the total airflow rate through the entire exhaust
the flow rates through each filter added together to determine
hood.
the total airflow rate through the entire exhaust hood.
10.2.3.3 The gross dimensions (height and width) of the
10.2.4.2 The body of the anemometer must remain parallel
opening areas of each filter shall be measured and recorded.
to the slot opening with one side in the same plane as the
10.2.3.4 The velometer shall traverse each opening a mini-
opening.
mum of 30 s. Fig. 4 shows the positions by “X” for an entire
10.2.4.3 The center of the anemometer shall be traversed
filter bank of cyclone filters.Average velocity readings shall be
across the center of the slot opening.
measured and recorded at each location.
10.2.4.4 Velocity measurements shall be made as a traverse
10.2.3.5 The body of the anemometer must remain 2 in.
through the center of each of the slot areas.The minimum time
from the exterior surface of the filters, and be kept parallel to
to uniformly traverse a slot opening shall be 30 s.
it.Asmallindicatorshallbeattachedtotheexteriorbodyofthe
10.2.4.5 The airflow through the anemometer shall not be
anemometer to maintain the 2 in. spacing.
obstructed by the operator’s hand or fingers.
10.2.3.6 The vane must attain full speed at each position
10.2.4.6 The fan blade shall attain full speed before record-
before the velocity is recorded.
ing any velocity data.
10.2.3.7 The airflow through the anemometer shall not be
10.2.4.7 The average velocity through each slot filter shall
...