ASHRAE Journal - January 2021 - 109

Products & technology section
The Importance of Accurate Automatic Airflow Balancing

A

ccurate balancing of an HVAC system has always been a challenge for
all buildings: residential, multi-family and
commercial. Proper and accurate balancing of an HVAC system ensures thermal
comfort, optimal system efficiency, and
acceptable indoor air quality. Traditional
methods of HVAC airflow balancing
cannot automatically adjust to the ever
changing system pressures created by
uncontrollable variables such as stack
effect, clogged filters, improper initial
balancing, duct or grille obstructions, etc.
Consistent airflow regulation has been
a standard practice for decades in Europe
and devices have been developed to serve
that market. Automatic Airflow Balancing
(AAB), a Metal Industries Inc. brand, is
proud to be the first manufacturer that has
developed the next generation of these
devices: the ABV - Automatic Balancing
Valve. The ABV is the first automatic
constant airflow regulating valve made in
the US with the US market in mind.

of previously developed models. The
ABV is completely adjustable from the
face of the unit. This ease of adjustability
allows the device to be field set and field
changed when needed. The ABV is also
the only product with Steri-Balance™ -
an anti-microbial agent infused into the
UL 94 thermoplastic. Steri-Balance™ is

not a coating, it will not wear off and will
continually prevent organic growth on the
ABV for the life of the product. The ABV
maintains a +/- 10% accuracy level while
operating at an astonishing 0.2-2.0 " WC.
The ABV also has a wide CFM range of
25-130 CFM (4 " and 5 " models) and 50275 CFM (6 " model).

Traditional Balancing Methods
Current HVAC balancing methods are
effective at the time of balancing; however
these methods are static in nature and cannot react to any pressure changes within
the HVAC duct. Such changes can be
caused by stack effect, where the temperature outside of the building varies greatly
from the internal temperature. Stack effect
creates issues especially in high rise buildings with shared vertical exhaust shafts
(hotels being a perfect example of this).
When high rise buildings use a shared
exhaust shaft for bathroom ventilation for
example, the outside temperature can create vast pressure changes causing hot air
within the shaft to rise much faster (winter
scenario). This stack effect can result in
over-exhausting on some floors and underexhausting on others. The former resulting
in wasted energy and the latter resulting
in IAQ issues.
The bottom line is that there are always
variables within an HVAC system that will
create pressure changes and without the
use of AAB's Automatic Balancing Valves,
the building will be wasting energy and
possibly causing IAQ issues.

The Next Generation
The ABV is the next generation of these
devices and has improved upon all aspects
JAN UARY 2021

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ASHRAE Journal - January 2021

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