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LEED v2009
Healthcare
Indoor Environmental Quality
Thermal comfort - design and verification

LEED CREDIT

Healthcare-v2009 IEQc7: Thermal comfort - design and verification 1 point

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Credit language

USGBC logo

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

Intent

Provide a comfortable thermal environment that supports and promotes occupant productivity and well-being and
provide for the assessment of building occupant’s thermal comfort over time.

Requirements

Design heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of one of the options below, and local codes or current 2010 FGI Guidelines for Design and Construction of Health Care Facilities (Table 2.1-2: Ventilation Requirements for Areas Affecting Patient Care in Hospitals and Outpatient Facilities), where local codes do not apply. Demonstrate design compliance in accordance with the Section 6.1.1 documentation.

Option 1. ASHRAE standard 55-2004 or non-U.S. equivalent
Meet the requirements of ASHRAE Standard 55-2004, Thermal Comfort Conditions for Human Occupancy (with errata but without addenda ). Demonstrate design compliance in accordance with the Section 6.1.1 documentation. Projects outside the U.S. may use a local equivalent to ASHRAE Standard 55-2004 Thermal Comfort Conditions for Human Occupancy Section 6.1.1.
Option 2. ISO 7730: 2005 & CEN standard EN 15251: 2007
Projects outside the U.S. may earn this credit by designing heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of International Organization for Standardization (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 CEN Standard EN 15251: 2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics. AND Provide a permanent monitoring system to ensure that the building performs to the desired comfort criteria as determined above. Agree to implement a thermal comfort survey of building occupants2 within a period of six to 18 months after occupancy. The survey shall 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. The plan shall include measurement of relevant environmental variables in problem areas in accordance with the standard selected above and 2010 FGI Guidelines for Design and Construction of Health Care Facilities.

1 Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.

2 In acute care hospitals and outpatient healthcare projects, occupants are defined as full-time staff. For residential health care occupancies, such as long term care or rehabilitation facilities, occupants include both full-time staff and residents.

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Addenda

7/1/2015Updated: 3/29/2018
Regional ACP
Description of change:
Append to first paragraph the following:

"Or the National Building Code of India 2005 (NBC 2005)"
After first paragraph add the following: "Projects in India may meet the desired comfort criteria specified in the following as a local equivalent to ASHRAE 55-2004:
  • For mechanically conditioned buildings, NBC 2005 Part 8, Section 3 - Table 2

  • For naturally conditioned buildings, NBC 2005 Part 8, Section 1 - Table 9"
Campus Applicable
Yes
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for nonoccupied spaces, "Nonoccupied spaces are defined as spaces designed for equipment and machinery or storage with no human occupancy except for maintenance, repairs, and equipment retrieval."
Campus Applicable
No
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for occupied spaces, "Occupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space."
Campus Applicable
No
Internationally Applicable:
No
10/1/2012Updated: 2/14/2015
Global ACP
Description of change:
Below option 2, add: "AND"
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012Updated: 2/14/2015
Global ACP
Description of change:
Add a new option that reads: "OPTION 2. ISO 7730: 2005 & CEN Standard EN 15251: 2007 Projects outside the U.S. may earn this credit by designing heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of International Organization for Standardization (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 CEN Standard EN 15251: 2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics."
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012Updated: 2/14/2015
Global ACP
Description of change:
The beginning of the first sentence of the Requirements section should read as follows: "Design heating, ventilating and air-conditioning (HVAC) systems to meet the requirements of one of the options below."
Campus Applicable
No
Internationally Applicable:
Yes
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for nonoccupied spaces, "Nonoccupied spaces are defined as spaces designed for equipment and machinery or storage with no human occupancy except for maintenance, repairs, and equipment retrieval."
Campus Applicable
No
Internationally Applicable:
No
11/1/2011Updated: 2/14/2015
Reference Guide Correction
Description of change:
In alphabetical order, add the following definition for occupied spaces, "Occupied Spaces are defined as enclosed spaces that can accommodate human activities. Occupied spaces are further classified as regularly occupied or non-regularly occupied spaces based on the duration of the occupancy, individual or multi-occupant based on the quantity of occupants, and densely or non-densely occupied spaces based upon the concentration of occupants in the space."
Campus Applicable
No
Internationally Applicable:
No
10/1/2012Updated: 2/14/2015
Global ACP
Description of change:
Replace "ASHRAE Standard 55-2004 (with errata but without addenda)" with "the standard selected above" in the last sentence of the credit language.
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012Updated: 2/14/2015
Global ACP
Description of change:
Add a new option that reads: "OPTION 1. ASHRAE Standard 55-2004 or Non-U.S. Equivalent Meet the requirements of ASHRAE Standard 55-2004, Thermal Comfort Conditions for Human Occupancy (with errata but without addenda). Demonstrate design compliance in accordance with the Section 6.1.1 documentation. Projects outside the U.S. may use a local equivalent to ASHRAE Standard 55-2004 Thermal Comfort Conditions for Human Occupancy Section 6.1.1."
Campus Applicable
No
Internationally Applicable:
Yes
4/1/2013
LEED Interpretation
Inquiry:

Can spaces that fall outside of the scope of ASHRAE 55-2004, because the physical activity levels result in a time-averaged MET above 2.0 (such as gymnasiums or fitness centers), be excluded from the credit requirements? Also, can spaces that are not normally comfort conditioned (such as warehouse spaces, apparatus bays, vehicle repair facilities, commercial kitchens) be excluded from the credit requirements?

Ruling:

**Updated October 1, 2013 to clarify the ruling.
No, spaces with a time-averaged metabolic rate above 2.0 MET must meet the requirements for IEQc7.1 Thermal Comfort—Design/IEQc2.3 Occupant Comfort—Thermal Comfort Monitoring. For these unique spaces, an alternative to the requirements of ASHRAE 55-2004 is acceptable provided the project determines acceptable thermal comfort conditions that meet the intent of the credit, and demonstrates that those conditions will be met. Time-weighted average metabolic rates should be determined based on guidance in ASHRAE 55-2004, Normative Appendix A. Most spaces with MET levels above 2.0 would need to meet the cooling / humidity temperature set points for spaces with MET levels of 2.0 in order to meet the intent of the credit. Exceptions will be considered on a case-by-case basis and must include an explanation that justifies how the intent of the credit is met. Kitchens may pursue this option.

Spaces that are not normally comfort conditioned can only be excluded if they are non-regularly occupied. For regularly occupied spaces that are not normally comfort conditioned, and not able to meet the ASHRAE 55 thermal comfort conditions, the project team must include one or more of the following design alternatives: radiant flooring; circulating fans; passive systems, such as nighttime air, heat venting, or wind flow; localized active cooling (refrigerant or evaporative-based systems) or heating systems; or localized, hard-wired fans that provide air movement for occupants’ comfort.

Campus Applicable
No
Internationally Applicable:
Yes
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Documentation toolkit

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USGBC logo

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

Intent

Provide a comfortable thermal environment that supports and promotes occupant productivity and well-being and
provide for the assessment of building occupant’s thermal comfort over time.

Requirements

Design heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of one of the options below, and local codes or current 2010 FGI Guidelines for Design and Construction of Health Care Facilities (Table 2.1-2: Ventilation Requirements for Areas Affecting Patient Care in Hospitals and Outpatient Facilities), where local codes do not apply. Demonstrate design compliance in accordance with the Section 6.1.1 documentation.

Option 1. ASHRAE standard 55-2004 or non-U.S. equivalent
Meet the requirements of ASHRAE Standard 55-2004, Thermal Comfort Conditions for Human Occupancy (with errata but without addenda ). Demonstrate design compliance in accordance with the Section 6.1.1 documentation. Projects outside the U.S. may use a local equivalent to ASHRAE Standard 55-2004 Thermal Comfort Conditions for Human Occupancy Section 6.1.1.
Option 2. ISO 7730: 2005 & CEN standard EN 15251: 2007
Projects outside the U.S. may earn this credit by designing heating, ventilating and air conditioning (HVAC) systems and the building envelope to meet the requirements of International Organization for Standardization (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 CEN Standard EN 15251: 2007, Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics. AND Provide a permanent monitoring system to ensure that the building performs to the desired comfort criteria as determined above. Agree to implement a thermal comfort survey of building occupants2 within a period of six to 18 months after occupancy. The survey shall 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. The plan shall include measurement of relevant environmental variables in problem areas in accordance with the standard selected above and 2010 FGI Guidelines for Design and Construction of Health Care Facilities.

1 Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.

2 In acute care hospitals and outpatient healthcare projects, occupants are defined as full-time staff. For residential health care occupancies, such as long term care or rehabilitation facilities, occupants include both full-time staff and residents.

In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit, for premium members only, saves you time and helps you avoid mistakes with:

  • Calculators to help assess credit compliance.
  • Tracking spreadsheets for materials purchases.
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  • Sample templates to help guide your narratives and LEED Online submissions.
  • Examples of actual submissions from certified LEED projects.
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