ASHRAE Journal - January 2015 - 70

TECHNICAL FEATURE

Analysis phase is recommended. If there are no perceived problems, the building should be benchmarked
against the ventilation criteria in ASHRAE Standard
62.1-2013.11 Outside air rates should be measured for
each ventilation system and room humidity measured in
representative spaces. Filter pressure drop is measured
and filters are changed as necessary.
For lighting/daylighting, more detailed building
space data are gathered, a lighting audit is conducted,
and illuminance measurements are made. These
activities can be conducted by properly trained, inhouse personnel or may require the use of an outside
professional. Spaces are identified that need pointby-point illuminance measurements. The results are
compared against lighting recommendations in the IES
Handbook.12
For acoustics measurements are taken to diagnose the extent of dissatisfaction identified in Basic
Evaluation. If building personnel are not skilled in
sound level measurements they should proceed to
the Advanced Analysis level. Dissatisfaction related
to background and intruding noise typically requires
measurements of A-weighted, equivalent sound pressure levels. If speech intelligibility is an issue, measuring room reverberation time is best conducted by a
skilled professional.

Advanced Analysis
At this level the services of a professional, with expertise specific to the measure category under consideration, is necessary.
Here, the energy performance evaluation focuses
on selected systems and equipment at higher levels of
granularity (i.e., hourly or 15 minute interval data),
using an energy analysis consultant, to determine the
location and cause of energy inefficiency. Detailed
interval data (operating temperatures and setpoints,
airflows, equipment status, valve and/or damper positions, etc.) is collected, typically using the EMCS/BAS,
and is compared to self-reference benchmarks that
indicate how the systems and equipment should be
operating.
An Advanced Analysis water assessment involves
detailed water use readings and advanced usage
analysis. Submeters improve the granularity of the
readings by measuring and normalizing items such as
HVAC and process water uses, subdivided landscape
70

ASHRAE JOURNAL

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JAN UARY 2015

Figure 5 Extended thermostat dead band zones providing thermal comfort.
(Courtesy of UC Berkeley Center for the Built Environment)
Conventional
Adaptive

Dead Band
Radiant

PECS

Free Running

Ceiling Fans

Personal Environmental Control Systems
61°F

64°F

68°F

71°F

75°F

79°F

82.4°F

86°F

areas, and recycled and/or harvested rainwater. Data
for leak rates and plumbing fixture water use are
analyzed and recommendations for improvement are
made.
To optimize thermal comfort performance one should
investigate all thermal elements in the indoor environment, as well as the occupant behavioral responses.
Strategies of adaptive control (adjusting temperature
dead band setpoints, reducing minimum supply air
volumes, controlling direct sunlight, and controlling
humidity independently of supply air temperature) and
providing local thermal comfort control options should
be addressed (Figure 5).
If IAQ evaluations indicate that further study is
needed, or if mold or non-obvious sources of odors
are identified, the Advanced Analysis IAQ methods
should be implemented with the help of an industrial
hygienist. Potential Contaminants of Concern (CofC)
are diagnosed and remediated by an IAQ specialist, as
needed.
Lighting/daylighting activities require the services
of a professional with lighting/daylighting expertise.
Measurement tasks include review of the walk-through
checklist (Appendix C of the Guide), surveying building occupants for lighting/daylighting satisfaction,
and development of an improvement plan. The review
should include the types of illuminance and luminance
instruments that are to be used.
Advanced Analysis for acoustics is required where
remediation is necessary but beyond the scope of the
building personnel. If the source of occupant dissatisfaction cannot be resolved then an acoustical consultant should be hired. The first tasks should be to review
the findings of the occupant survey and to conduct
a precise assessment of the background noise and
reverberation time in rooms where there is acoustic
annoyance.

ASHRAE Journal - January 2015

Table of Contents for the Digital Edition of ASHRAE Journal - January 2015