Section 2: Individual LEED Credit Reviews
LEED Credit ID-1.1:
Greater control of the amount of outside air
supplied to specific building zones.
Dedicated Ventilation
Continuous building pressurization during the
non-occupied hours of the building. The
System
pressurization forces dry, tempered air to
exfiltrate the building, thereby reducing the
amount of outside air that can infiltrate during
Intent (for all Innovation in Design Credits)
humid weather (the system runs at neutral
pressure during cold weather). The exfiltrating
To provide design teams and projects the
air can also act to dry out moisture that may
opportunity to be awarded points for exceptional
have condensed within the exterior wall
performance above and beyond the
assemblies of the building. Overall, the intent
requirements set by the LEED Green Building
of the pressurization is to reduce the potential
Rating System and/or innovative performance in
for moisture build-up and mold growth in the
Green Building categories not specifically
building envelope.
addressed by the LEED Green Building Rating
Reduced use of the larger HVAC systems
System.
during after-hour operations. The dedicated
Requirement
ventilation units can be used to provide
conditioning in the building when small
In writing, identify the intent of the proposed
groups of employees are working off-hours.
innovation credit, the proposed requirement for
This reduces the building's energy use during
compliance, the proposed submittals to
these periods.
demonstrate compliance, and the design
Although it is comprised of standard HVAC
approach (strategies) that might be used to meet
system components, the dedicated ventilation
the requirements.
system is an innovative approach to building
(1 point)
ventilation that has potential long-term indoor air
quality and durability benefits.
Cost Impact = 1
Basis for Cost Assumption
Both the Courthouse and Office Building models
1
2
3
4
5
include dedicated ventilation systems in the
baseline reference costs. The systems are
GSA
No
Low
Moderate
High
comprised of 4,000 cfm air handling units (1 per
Standard
premium,
premium
premium
premium
floor), with associated air distribution ductwork,
(no cost)
psble svgs
(<50K)
(50-150K)
(>150K)
controls, and electric power wiring. While there is
no LEED cost premium to provide these systems,
Practical Applications
the reference cost estimates identify the following
costs for the dedicated ventilation systems:
A LEED Innovation and Design (ID) credit can
potentially be earned based on GSA's P100
Courthouse:
0,500
requirement to provide 100 percent outside air
Office Building: 9,624
dedicated ventilation systems in all new buildings
and major renovation projects. The dedicated
These are estimated Direct Construction Costs,
ventilation units provide tempered, dehumidified
which do not include contingencies and other
air to the building, and are independent of other air
allowances.
distribution systems. By separating and
conditioning the outside air through the dedicated
ventilation units, GSA intends to achieve the
following benefits:
GSA LEED COST STUDY
157
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