Log in
LEED v4.1

Commercial Interiors

Indoor Environmental Quality
Thermal Comfort

LEED CREDIT

CI-v4.1 EQc5: Thermal comfort 1 point

LEEDuser’s viewpoint

Frank advice from LEED experts

LEED is changing all the time, and every project is unique. Even seasoned professionals can miss a critical detail and lose a credit or even a prerequisite at the last minute. Our expert advice guides our LEEDuser Premium members and saves you valuable time.

Credit language

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To promote occupants’ productivity, comfort, and well-being by providing quality thermal comfort.

Requirements

Meet the requirements for both thermal comfort design and thermal comfort control.

Thermal Comfort Design
Design heating, ventilating, and air-conditioning (HVAC) systems and the building envelope to meet the requirements of ASHRAE Standard 55–2017, Thermal Comfort Conditions for Human Occupancy with errata or a local equivalent. For natatoriums, demonstrate compliance with ASHRAE HVAC Applications Handbook, 2011 edition, Chapter 5, Places of Assembly, Typical Natatorium Design Conditions, with errata.
Thermal Comfort Control
Provide individual thermal comfort controls for at least 50% of individual occupant spaces. Provide group thermal comfort controls for all shared multioccupant spaces. Thermal comfort controls allow occupants, whether in individual spaces or shared multioccupant spaces, to adjust at least one of the following in their local environment: air temperature, radiant temperature, air speed, and humidity. See all forum discussions about this credit »

What does it cost?

Cost estimates for this credit

On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.

Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.

This information is also available in a full PDF download in The Cost of LEED v4 report.

Learn more about The Cost of LEED v4 »

Addenda

11/9/2020Updated: 11/30/2020
Reference Guide Correction
Description of change:
replace Behind the Intent, Beta Update text with the following:
The ASHRAE standards have been updated to the latest versions:
 ASHRAE 55-2010  ASHRAE 55-2017 (updated version)
o Major changes from 2010 include: clarifications to elevated air speed method, new requirement to calculate the change to thermal comfort resulting from direct solar radiation impacting occupants.
 ASHRAE Applications Handbook 2011 edition  ASHRAE Applications Handbook 2015 edition (updated version)
Option 2 is available for use through regional compliance pathways.

Under Step-by-Step Guidance, replace with the following:
Step 1. Select Analysis Method(s)
Select the methodology from ASHRAE Standard 55-2017 that will be used for the thermal comfort analysis. Refer to the standard for restrictions with some of the methods. For example, section 5.3.1 is restricted to conditions without direct solar radiation.
Additional calculations or considerations required if direct-beam solar radiation falls on the occupant. Calculations are available in ASHRAE 55-2017 Normative Appendix C.
Tools such as the CBE Thermal Comfort Tool (https://comfort.cbe.berkeley.edu/) may be used to assist with the analysis. A new feature (SolarCal) is also available for the direct-beam solar radiation calculations.
Step 2. Design Project’s Conditioning Systems
Design the project’s conditioning systems to provide the acceptable comfort conditions identified in the analysis. Verify that all spaces at risk for discomfort, such as locations close to the entrances prone to drafts or west-facing walls that may retain heat, have been addressed.
ASHRAE 55–2017, Section 6.1, requires the design to be within the acceptable comfort range at all combinations of conditions that are expected to occur, including variations in internal loads and the exterior environment, and at both full- and partial-load conditions. Systems that cannot maintain comfort under all conditions (e.g., a constant-volume rooftop unit with a single compressor may have problems controlling humidity levels) do not meet the credit requirements.

Under Required Documentation, replace with the following:
Refer to LEED v4 ref guide with the following modifications:
 For thermal comfort design compliance, supporting documentation verifying that the thermally conditioned spaces meet ASHRAE Standard 55-2017 for 80% acceptability. Examples include a psychometric chart, PMV/PPD calculations, CBE Thermal Comfort Tool results, a copy of ASHRAE Standard 55-2017 Figure I2, Figure I4, and/or Figure I5, or predicted worst case (both heating and cooling) indoor conditions for each month on a copy of ASHRAE Standard 55-2017 Figure 5.4.2.
 Explanation of how project complies with the direct solar radiation requirements in ASHRAE Standard 55-2017.
o Screenshots of the local discomfort assessment and SolarCal windows from the CBE Thermal Comfort Tool are acceptable.



Campus Applicable
No
Internationally Applicable:
No
11/9/2020Updated: 11/30/2020
Rating System Correction
Description of change:
Delete Option 1 header text "Option 1. ASHRAE Standard 55-2017"
Delete Option 2 text :
"OR
Option 2. ISO Standards
Design HVAC systems and the building envelope to meet the requirements of the applicable standard:
• ISO 7730:2005, Ergonomics of the Thermal Environment, analytical determination and interpretation of thermal comfort, using calculation of the PMV and PPD indices and local thermal comfort criteria; and
• ISO 17772-2017, Energy Performance of Buildings- Indoor environmental quality- Part 1. Indoor environmental input parameters for the design and assessment of energy performance of buildings Section A2."
Campus Applicable
No
Internationally Applicable:
No
See all forum discussions about this credit »

Documentation toolkit

The motherlode of cheat sheets

LEEDuser’s Documentation Toolkit is loaded with calculators to help assess credit compliance, tracking spreadsheets for materials, sample templates to help guide your narratives and LEED Online submissions, and examples of actual submissions from certified LEED projects for you to check your work against. To get your plaque, start with the right toolkit.

LEEDuser expert

Tyler Thumma

7Group

Get the inside scoop

Our editors have written a detailed analysis of nearly every LEED credit, and LEEDuser premium members get full access. We’ll tell you whether the credit is easy to accomplish or better left alone, and we provide insider tips on how to document it successfully.

USGBC logo

© Copyright U.S. Green Building Council, Inc. All rights reserved.

Intent

To promote occupants’ productivity, comfort, and well-being by providing quality thermal comfort.

Requirements

Meet the requirements for both thermal comfort design and thermal comfort control.

Thermal Comfort Design
Design heating, ventilating, and air-conditioning (HVAC) systems and the building envelope to meet the requirements of ASHRAE Standard 55–2017, Thermal Comfort Conditions for Human Occupancy with errata or a local equivalent. For natatoriums, demonstrate compliance with ASHRAE HVAC Applications Handbook, 2011 edition, Chapter 5, Places of Assembly, Typical Natatorium Design Conditions, with errata.
Thermal Comfort Control
Provide individual thermal comfort controls for at least 50% of individual occupant spaces. Provide group thermal comfort controls for all shared multioccupant spaces. Thermal comfort controls allow occupants, whether in individual spaces or shared multioccupant spaces, to adjust at least one of the following in their local environment: air temperature, radiant temperature, air speed, and humidity.

LEEDuser expert

Tyler Thumma

7Group

See all LEEDuser forum discussions about this credit » Subscribe to new discussions about CI-v4.1 EQc5