Dwyer 100 User Manual

Durablock®Air Volume Gage

Specifications - Installation and Operating Instructions

TO TEST FOR AIR FLOW VOLUME WHEN INSTALLING AND SERVICING

RESIDENTIAL AND SMALL CENTRAL AIR CONDITIONING SYSTEMS

Bulletin H-30

For field or laboratory use ...

The Dwyer
air conditioning and heating engineers that has proven to be
extremely useful both in the field and in the laboratory. Portable
and highly accurate, this instrument fills the need for an
instrument to accurately determine the volume of air flowing
through air conditioning coils. An indispensable aid in proving
out cooling system installations, the Dwyer
helps to avoid poor performance and mechanical failure. It
shows the installer or engineer exactly when more or less air is
needed to keep within the critical limits necessary for the most
efficient and trouble-free cooling system operation.

Accurate, simple to use ...

Field methods for determining air flow volume in air conditioning
equipment have traditionally been rough and inaccurate.
Anemometers and other types of air speed indicators are
inadequate for volume measurements because of both velocity
variations at each register and extreme turbulence throughout
the system. Nor do mathematical computations accurately
indicate effective free area for air flow in the system. In contrast,
the Dwyer
across cooling coils and offers a highly practical way of
determining flow volume.

INSTALLATION ...

Simply level, adjust for zero, attach static lines and insert Trail­Tails in test holes. Pressure drop is then read in inches of water
column. The reading can be quickly converted to volume flow by
referring to the manufacturer’s pressure and flow curves
furnished with the cooling unit.

®

Air Volume Gage is a precision-built instrument for

®

Air Volume Gage

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Air Volume Gage measures the static pressure drop

FEATURES

• ALSO USEFUL

For ventilating, heating, refrigeration and air filter systems:
indicates air volume flow, furnace draft, filter condition,
plenum pressure, etc.

• READY TO USE

Simple to assemble, hook up, and take readings.

• PERMANENTLY ACCURATE

No delicate parts to get out of order, no moving parts of any
kind, accuracy remains constant.

• DURABLOCK

Construction of solid transparent plastic, virtually
indestructible and permanently accurate.

• COMPACT GAGE DIMENSIONS

6-3/8˝ x 3˝ x 1˝ (16.19 cm x 7.62 cm x 2.54 cm).

DWYER INSTRUMENTS, INC.

Phone: [phone] www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [e-mail]

Small and portable ...

To determine cooling capacity of air conditioning systems, the
American Society of Refrigeration Engineers requires that air
volume be established by measuring static pressure differential
across a calibrated test orifice with an elliptic curve approach.
This laboratory test is highly accurate, but impractical for field
use because of the large, cumbersome equipment involved. The

®

Dwyer
p

Air Volume Gage static pressure sensors offers a

ositive solution to this problem. This compact gage combines

laboratory accuracy, field-use versatility and ease of operation.

Saves time, saves work ...

Leading cooling equipment manufacturers furnish coil
performance data showing the static pressure differential across
each coil along with the equivalent volume flow and peak cooling
point. This data is determined in laboratory hot rooms with air
flow accurately measured by ASRE standard methods.
Recommended static pressure differentials usually run between
.10˝ and .20˝ water column (.2482 mbar and .4964 mbar).
Maximum cooling capacity is usually found in the range of 400
c.f.m. (11,326.4 LPM) for each 12,000 b.t.u. of cooling. Using the

®

Dwyer

Air Volume Gage static pressure sensors, the air
conditioning engineer or installer can accurately measure air
pressure differential across a cooling coil. With this information,
the user may determine air volume flow from the manufacturer’s
data, thus bringing laboratory accuracy into the field.
Adjustments in blower speed can then be made to exactly
duplicate the manufacturer’s recommended operating point.
Conditions which would lead to mechanical failure are avoided
and peak performance is assured.

YPICAL HI-BOY FURNACE

T

WITH COOLING COIL IN PLENUM

MAGNECLIPS

This valuable accessory, furnished as standard equipment with
each Dwyer

®

portable air volume gage, allows rapid positioning
of the gage on any vertical iron or steel surface. Just touch the
Magneclip-equipped gage to the side of the duct, plenum or
other convenient surface. It grips instantly and securely, freeing
hands for other work.

©Copyright 2013 Dwyer Instruments, Inc. Printed in U.S.A. 5/13 FR# 31-440246-00 Rev. 7

DWYER INSTRUMENTS, INC.

Phone: [phone] www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A. Fax: [phone] e-mail: [e-mail]