Page 319 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

LEED Indoor Envir onmental Quality 281

Special Circumstances and Exemplary Performance As mentioned in IEQc6.2, thermal
comfort control as described in ASHRAE Standard 55-2004 should be balanced with the
minimum indoor air quality requirements, as required per ASHRAE Standard 62.1-
2004. In addition, lighting can affect thermal comfort, and its impacts should be
considered in the designs. Also, since many of the features for thermal comfort relate to
windows and the HVAC systems, this credit has been labeled with an EB from the
USGBC. It is more difficult to change in an existing building. There is no exemplary
performance point for this credit for either LEED version 2.2 or 2009.

IEQ Credit 7.2: Thermal Comfort—Verification
Again, thermal comfort is based on many environmental and personal factors, and it is
also addressed in IEQc6.2 and IEQc7.1. This credit, IEQc7.2, deals with verifying that
the occupants of the building feel that they have an adequate level of thermal comfort.
IEQc7.2 is worth one point in both LEED 2.2 and LEED 2009, but in LEED 2009 is only
in addition to one point earned in IEQc7.1.

USGBC Rating System
LEED-NC 2.2 lists the Intent, Requirements, and Potential Technologies and Strategies
for IEQc7.2 as follows, with modifications to reflect updates in LEED 2009, most notably
these three; the requirement to also achieve IEQc7.1, ineligibility for residential projects,
and the requirement to provide a permanent monitoring system to ensure compliance
with IEQc7.1:

Intent
Provide for the assessment of building thermal comfort over time.
Requirements
Achieve IEQc7.1: Thermal Comfort-Design (LEED 2009)
AND
Provide a permanent monitoring system to ensure performance meets the desired comfort
criteria in the IEQc7.1 design (LEED 2009).
AND
Residential projects are not eligible (LEED 2009)
AND
Agree to implement a thermal comfort survey of building occupants within a period of six to
18 months after occupancy. This survey should collect anonymous responses about thermal
comfort in the building including an assessment of overall satisfaction with thermal performance
and identification of thermal comfort-related problems. Agree to develop a plan for corrective
action if the survey results indicate that more than 20% of occupants are dissatisfied with
thermal comfort in the building. This plan should include measurement of relevant
environmental variables in problem areas in accordance with ASHRAE Standard 55-2004, with
errata but without addenda. Project teams can choose to use the addenda to ASHRAE 55-2004,
but only if applied consistently over all the credits applied for the LEED 2009.

Potential Technologies and Strategies
ASHRAE Standard 55-2004 provides guidance for establishing thermal comfort criteria and
the documentation and validation of building performance to the criteria. While the
standard is not intended for purposes of continuous monitoring and maintenance of the
thermal environment, the principles expressed in the standard provide a basis for design of
monitoring and corrective action systems.