38 | aPPLIcatIon GuIdeLIneS
Single Zone High Efficiency W
all Mount Engineering Manual
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LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG ” is a registered trademark of LG Corp.
bUilDing VenTilATion DeSign gUiDe
building Ventilation Design guide
ASHRAE 62.1 and local codes specify the minimum volume of outdoor air that must be provided to an occupied space. outdoor air is
required to minimize adverse health effects, and it provides acceptable indoor air quality for building occupants. The three methods of
accomplishing this with single zone systems are summarized here.
Although we believe that these building ventilation methods have been portrayed accurately, none of the methods have been tested, verified, or
evaluated by LG Electronics, U.S.A., Inc., In all cases, the designer, installer, and contractor should understand if the suggested method is used, it
is used at their own risk. LG Electronics U.S.A., Inc., takes no responsibility and offers no warranty, expressed or implied, in law or in fact, including
but not limited to any implied warranty of merchantability or fitness for a particular purpose.
• For a complete copy of Standard 62.1-2010, refer to the American Standard of Heating and Air Conditioning Engineers (ASHRAE)
website at www.ashrae.org.
• For more information on how to properly size a ventilation air pretreatment system, refer to the article, “Selecting DOAS Equipment with
Reserve Capacity” by John Murphy, published in the ASHRAE Journal, April 2010.
Method 1: Decoupled Dedicated outdoor Air System (DDoAS)
Advantages
• May be used with single zone systems.
• The outdoor air unit may supply “neutral” air to the occupant space
even when the single zone system indoor unit fan changes speed
or cycles on and off. DDoAS controls do not have to be interlocked
with the single zone system.
• In lieu of installing localized smaller outside air treatment
equipment throughout the building, this method centralizes the
ventilation air source making service and filter changes easier and
less disruptive for the building occupants.
• Third-party demand control ventilation controls are more readily
accommodated.
Disadvantages
• Ceiling space is required to accommodate ductwork between the
centralized outdoor air unit and ceiling diffusers.
LG recommends using the DDOAS method in all installations.
Provide a separate, dedicated outdoor-air system designed to filter, condition, and dehumidify ventilation air and deliver it directly to
the conditioned space through a separate register or grille. This approach requires a separate independent ventilation duct system not
associated with single systems (Figure 9).
Methodology illustrations are for examples only and do not depict
actual indoor units for the specific outdoor unit pairing. These are
generic illustrations to show ventilation design only.
Figure 9: Decoupled Dedicated outdoor System Diagram.
Ceiling Diffuser
Outdoor Air Unit / ERV
Outdoor Air
Wall Mount Inverter
Intake Grill
