{"id":18339,"feature_order":6,"feature_code":null,"name":"Enhanced Ventilation Design","type":"O","intent":"Expel internally generated pollutants and improve air quality in the breathing zone through an increased supply of outdoor air or increased ventilation efficiency.","intervention":"This WELL feature requires implementation of advanced ventilation strategies that can achieve higher air quality levels and thus benefit human health and productivity.","issue":"The majority of ventilation standards specify ventilation rates and other measures intended to provide indoor air quality that is merely \u201cacceptable\u201d to building users and reduces the risk of adverse health effects.1<\/sup> Even with proper ventilation designed to meet ventilation standards, the concentration of indoor pollutants can exceed concentrations found in outdoor air.2,3 <\/sup>Ventilation rates less than {{well-unit}}21 cfm|10 L\/s{{\/well-unit}} per person in all building types are associated with negative perception of air quality and actual health outcomes.4<\/sup>
","evidence":"\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n

Scientific research suggests that an airflow rate significantly exceeding that recommended by standards is needed to minimize sick building syndrome symptoms and to improve human performance and productivity.5,6<\/sup> Since it is difficult to test for every potential pollutant, and because carbon dioxide (CO2<\/sub>) is easy to detect, CO2<\/sub> levels serve as a proxy for other indoor pollutants. A number of CO2<\/sub> studies suggest that the risk of sick building syndrome symptoms decreases significantly, when CO2<\/sub> concentrations are less than 800 ppm.4<\/sup> One method for decreasing the CO2 concentration experienced by occupants while minimizing additional energy use is demand-controlled ventilation, in which the delivery rate for outside air is directly linked to the measured CO2 levels within the space.7<\/sup> Displacement ventilation improves indoor air quality, by delivering fresh outdoor air at the floor level, leaving warmer polluted indoor air, such as CO2<\/sub> to be extracted above the height of the ventilation zone.8<\/sup>
<\/o:p><\/p>","implementation":"","impact":"","max_points":3,"concept_id":1734,"slug":"enhanced-ventilation-1","gbd_exists":null,"review_summary":null,"citations":"

1. \t<\/span>Allen JG, Bernstein A, Cao X, et al. The 9 Foundations of a Healthy Building. Sch Public Heal. 2017:35.<\/div>
2. \t<\/span>Parthasarathy, Srinandini, William J. Fisk TEM. Effect Of Ventilation On Chronic Health Risks In Schools And Offices. Berkeley, CA; 2013. https:\/\/eta.lbl.gov\/sites\/all\/files\/publications\/lbnl-6121e.pdf.<\/div>
3. \t<\/span>Shendell DG, Winer AM, Weker R, Colome SD. Evidence of inadequate ventilation in portable classrooms: Results of a pilot study in Los Angeles County. Indoor Air. 2004;14(3):154-158. doi:10.1111\/j.1600-0668.2004.00235.x<\/div>
4. \t<\/span>Sepp\u00e4nen OA. Association of ventilation rates and CO2concentrations with health and other responses in commercial and institutional buildings. Indoor Air. 1999;9(4):226-252. doi:10.1111\/j.1600-0668.1999.00003.x<\/div>
5. \t<\/span>Wyon DP. The effects of indoor air quality on performance and productivity. Indoor Air, Suppl. 2004;14(SUPPL. 7):92-101. doi:10.1111\/j.1600-0668.2004.00278.x<\/div>
6. \t<\/span>Sundell J, Levin H, Nazaroff WW, et al. Ventilation rates and health: Multidisciplinary review of the scientific literature. Indoor Air. 2011;21(3):191-204. doi:10.1111\/j.1600-0668.2010.00703.x<\/div>
7. \t<\/span>U.S. Department of Energy. Demand Control Ventilation. 2012.<\/div>
8. \t<\/span>Wang Y, Kuckelkorn J, Zhao FY, Spliethoff H. Indoor environment of a classroom in a passive school building with displacement ventilation. Proc BS 2013 13th Conf Int Build Perform Simul Assoc. 2013:1902-1909.<\/div>
9. \t<\/span>American Society of Heating Refrigerating and Air-Conditioning Engineers. Performance Evaluation and Development of Design Guidelines for Displacement Ventilation, RP-949.; 1998.<\/div>
10. \t<\/span>American Society of Heating Refrigerating and Air-Conditioning Engineers. ASHRAE 62.1-2019: Ventilation for Acceptable Indoor Air Quality. 2019.<\/div>
11. \t<\/span>Skistad H, Mundt E, Nielsen P V., Hagstrom K, Railio J. Displacement Ventilation in Non-Industrial Premises. REHVA Guidebook No. 1. Rehva; 2002.<\/div>","deleted_at":null,"equivalency_count":21,"faq_count":1,"resource_count":0,"feature_full_name":"A06 Enhanced Ventilation Design","feature_faq_name":"A06 Enhanced Ventilation Design-v2","max_core_points":5,"parts":[{"id":30678,"name":"Increase Outdoor Air Supply","part_number":1,"points":2,"possible_points":["1","2"],"core_points":3,"possible_core_points":["2","3"],"min_points":1,"rer_points":3,"wor_points":0,"parent_part_id":null,"feature_id":18339,"note":"\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\nMixed-mode projects must select the option corresponding to the ventilation\r\nmode (mechanical and natural ventilation) in operation for the majority of\r\noperating hours within the year.<\/span>","slug":"1-increase-outdoor-air-supply-40","note_position_override":"bottom","new_core_shell":null,"existing_core_shell":null,"new_occupied":null,"existing_occupied":null,"education":null,"retail":null,"mfr":null,"others":null,"photographic_verification":null,"gbd_exists":null,"hospitality":null,"assisted_living":null,"cultural_institutions":null,"public_assembly":null,"deleted_at":null,"na_alternative":0,"na_alternative_text":null,"leed_well":1,"part_prefix":"A06.1","feature_name":"Enhanced Ventilation Design","parent":null,"sub_parts":[{"id":32966,"condition":"OR","part_id":30678,"deleted_at":null,"space_types_included":[{"id":1,"name":"All Spaces","name_plural":"all"}],"space_types_excluded":[],"options":[{"id":41848,"option_order":1,"name":"Increased air supply","description":"

For mechanically ventilated buildings, the following requirement is met in all occupiable spaces:<\/p>","description_alt":null,"space_property":null,"certification":null,"note":null,"sub_part_id":32966,"deleted_at":null,"note_position_override":"top","verification_note":null,"verification_condition":"AND","requirements":[{"id":120268,"option_id":41848,"requirement_order":1,"description":"

Exceed outdoor air supply rates described in one of the ventilation guidelines listed in Feature A03 Part 1 by the percentages shown in the table below:<\/p>\r\n\r\n\r\n\t\r\n\t\t\r\n\t\t\t\r\n\t\t\t\r\n\t\t\t
Tier<\/strong><\/td>\r\n\t\t\tThresholds<\/strong><\/td>\r\n\t\t\tPoints<\/strong><\/td>\r\n\t\t<\/tr>\r\n\t\t
1<\/td>\r\n\t\t\t30%<\/td>\r\n\t\t\t\r\n\t\t\t

{{well-points}} 1|2 {{\/well-points}}<\/p>\r\n\t\t\t<\/td>\r\n\t\t<\/tr>\r\n\t\t

2<\/td>\r\n\t\t\t60%<\/td>\r\n\t\t\t\r\n\t\t\t

{{well-points}} 2|3{{\/well-points}}<\/p>\r\n\t\t\t<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>","description_alt":null,"deleted_at":null,"photographic_verification":0}],"verifications":[{"id":11,"name":"Letter of Assurance \u2013 Engineer","chinese_name":"\u4fdd\u8bc1\u4e66\uff0d\u5de5\u7a0b\u5e08","is_auditable":0,"scale_type":"Shareable","note":"Project teams should complete all fillable fields in the PDF for LOA approval."}],"pvgbs":[]},{"id":41849,"option_order":2,"name":"Demand control ventilation","description":"

For mechanically ventilated buildlings, the following requirements are met in at least 90% of regularly occupied spaces:<\/p>","description_alt":null,"space_property":null,"certification":null,"note":null,"sub_part_id":32966,"deleted_at":null,"note_position_override":"top","verification_note":null,"verification_condition":"AND","requirements":[{"id":120269,"option_id":41849,"requirement_order":1,"description":"

A demand-controlled ventilation (DCV) system regulates the outdoor air ventilation rate to keep CO2<\/sub> levels less than the thresholds specified in the table below, at the maximum intended occupancy: <\/p>\r\n\r\n\r\n\t\r\n\t\t\r\n\t\t\t\r\n\t\t\t\r\n\t\t\t
Tier<\/strong><\/td>\r\n\t\t\tThreshold<\/strong><\/td>\r\n\t\t\t <\/td>\r\n\t\t\tThreshold<\/strong><\/td>\r\n\t\t\tPoints<\/strong><\/td>\r\n\t\t<\/tr>\r\n\t\t
1<\/td>\r\n\t\t\t900 ppm<\/td>\r\n\t\t\tOR<\/td>\r\n\t\t\t500 ppm above outdoor levels<\/td>\r\n\t\t\t\r\n\t\t\t

 <\/p>\r\n\r\n\t\t\t

{{well-points}} 1|2 {{\/well-points}}<\/p>\r\n\t\t\t<\/td>\r\n\t\t<\/tr>\r\n\t\t

2<\/td>\r\n\t\t\t750 ppm<\/td>\r\n\t\t\tOR<\/td>\r\n\t\t\t350 ppm above outdoor levels<\/td>\r\n\t\t\t\r\n\t\t\t

{{well-points}} 2|3{{\/well-points}}<\/p>\r\n\t\t\t<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>","description_alt":null,"deleted_at":null,"photographic_verification":0},{"id":120270,"option_id":41849,"requirement_order":2,"description":"

Carbon dioxide is measured at the return air diffusers or in the breathing zone at least {{well-unit}}3.3 ft|1 m{{\/well-unit}} away from doors, windows, air supply diffusers or occupants. At least one sensor is used for each occupancy zone (or per air handling unit, if a single zone is served by multiple air handling units). If the occupancy density\/pattern\/usage is substantially different in two adjacent areas, each area must be considered a separate zone.<\/p>","description_alt":null,"deleted_at":null,"photographic_verification":0}],"verifications":[{"id":11,"name":"Letter of Assurance \u2013 Engineer","chinese_name":"\u4fdd\u8bc1\u4e66\uff0d\u5de5\u7a0b\u5e08","is_auditable":0,"scale_type":"Shareable","note":"Project teams should complete all fillable fields in the PDF for LOA approval."}],"pvgbs":[]},{"id":41850,"option_order":3,"name":"Enhanced natural ventilation","description":"

For naturally ventilated buildings, the following requirement is met:<\/p>","description_alt":null,"space_property":null,"certification":null,"note":null,"sub_part_id":32966,"deleted_at":null,"note_position_override":"bottom","verification_note":"

Modeling report or room-by-room CO2 <\/sub>calculations<\/p>","verification_condition":"AND","requirements":[{"id":120271,"option_id":41850,"requirement_order":null,"description":"

Implement an engineered natural ventilation system that is sufficient to keep CO2<\/sub> levels in the breathing zone of all regularly occupied spaces below the specified thresholds at the maximum intended occupancies:<\/p>\r\n\r\n\r\n\t\r\n\t\t\r\n\t\t\t\r\n\t\t\t\r\n\t\t\t
Tier<\/strong><\/td>\r\n\t\t\tThreshold<\/strong><\/td>\r\n\t\t\t <\/td>\r\n\t\t\tThreshold<\/strong><\/td>\r\n\t\t\tPoints<\/strong><\/td>\r\n\t\t<\/tr>\r\n\t\t
1<\/td>\r\n\t\t\t900 ppm<\/td>\r\n\t\t\tOR<\/td>\r\n\t\t\t500 ppm above outdoor levels<\/td>\r\n\t\t\t\r\n\t\t\t

{{well-points}} 1|2 {{\/well-points}}<\/p>\r\n\t\t\t<\/td>\r\n\t\t<\/tr>\r\n\t\t

2<\/td>\r\n\t\t\t750 ppm<\/td>\r\n\t\t\tOR<\/td>\r\n\t\t\t350 ppm above outdoor levels<\/td>\r\n\t\t\t\r\n\t\t\t

{{well-points}} 2|3{{\/well-points}}<\/p>\r\n\t\t\t<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>","description_alt":null,"deleted_at":null,"photographic_verification":0}],"verifications":[{"id":3,"name":"Technical Document (Audited)","chinese_name":"\u6280\u672f\u6587\u6863\uff08\u5ba1\u8ba1\uff09","is_auditable":1,"scale_type":"Audited","note":null}],"pvgbs":[]},{"id":41851,"option_order":4,"name":"Ventilation monitoring","description":"

One of the following carbon dioxide thresholds is met in occupiable spaces:<\/p>","description_alt":null,"space_property":null,"certification":null,"note":"

This Option is worth {{well-points}}2|3{{\/well-points}} points.<\/p>\r\n\r\n

Refer to the Performance Verification Guidebook for information on sensor\/testing requirements, required testing duration and compliance calculations.<\/p>","sub_part_id":32966,"deleted_at":null,"note_position_override":"bottom","verification_note":null,"verification_condition":"AND","requirements":[{"id":120272,"option_id":41851,"requirement_order":1,"description":"

750 ppm or less.<\/p>","description_alt":null,"deleted_at":null,"photographic_verification":0},{"id":120273,"option_id":41851,"requirement_order":2,"description":"

Not more than 350 ppm above outdoor levels.<\/p>","description_alt":null,"deleted_at":null,"photographic_verification":0}],"verifications":[{"id":24,"name":"Sensor Data","chinese_name":"\u4f20\u611f\u5668\u6570\u636e","is_auditable":0,"scale_type":"Individual","note":null}],"pvgbs":[]}]}],"on_sites":[],"annotated_documents":[],"letter_of_assurances":[],"part_guidances":[{"id":33092,"part_id":30678,"category":"WELL Core","sub_category":null,"rating_note":null,"alignment_note":null,"doc_guidance":"Meet these requirement in the whole building. If the project pursues Option 1 or Option 2, it must provide leased spaces with sufficient outdoor air and a compatible control system (as applicable) but is not required to install ducts and diffusers within leased spaces.","points":null}],"methods":[]},{"id":30685,"name":"Improve Ventilation Effectiveness","part_number":2,"points":1,"possible_points":null,"core_points":2,"possible_core_points":null,"min_points":0,"rer_points":2,"wor_points":0,"parent_part_id":null,"feature_id":18339,"note":"","slug":"2-improve-ventilation-effectiveness-16","note_position_override":"top","new_core_shell":null,"existing_core_shell":null,"new_occupied":null,"existing_occupied":null,"education":null,"retail":null,"mfr":null,"others":null,"photographic_verification":null,"gbd_exists":null,"hospitality":null,"assisted_living":null,"cultural_institutions":null,"public_assembly":null,"deleted_at":null,"na_alternative":0,"na_alternative_text":null,"leed_well":0,"part_prefix":"A06.2","feature_name":"Enhanced Ventilation Design","parent":null,"sub_parts":[{"id":32975,"condition":"OR","part_id":30685,"deleted_at":null,"space_types_included":[{"id":1,"name":"All Spaces","name_plural":"all"}],"space_types_excluded":[],"options":[{"id":41864,"option_order":1,"name":"Displacement ventilation system","description":"The project uses a displacement ventilation system in at least 90% of regularly occupied spaces, with one of the following as a basis for design:","description_alt":null,"space_property":null,"certification":null,"note":null,"sub_part_id":32975,"deleted_at":null,"note_position_override":"top","verification_note":null,"verification_condition":"AND","requirements":[{"id":120307,"option_id":41864,"requirement_order":1,"description":"

ASHRAE Guidelines RP-949.9<\/sup><\/o:p><\/p>","description_alt":null,"deleted_at":null,"photographic_verification":null},{"id":120308,"option_id":41864,"requirement_order":2,"description":"

ASHRAE 62.1-2019, \"Stratified Air Distribution Systems (Section 6.2.1.2.1).10<\/sup><\/o:p><\/p>","description_alt":null,"deleted_at":null,"photographic_verification":null},{"id":120309,"option_id":41864,"requirement_order":3,"description":"

REHVA Guidebook No. 01 (Displacement Ventilation in non-industrial premises).11<\/sup><\/o:p><\/p>","description_alt":null,"deleted_at":null,"photographic_verification":null}],"verifications":[{"id":11,"name":"Letter of Assurance \u2013 Engineer","chinese_name":"\u4fdd\u8bc1\u4e66\uff0d\u5de5\u7a0b\u5e08","is_auditable":0,"scale_type":"Shareable","note":"Project teams should complete all fillable fields in the PDF for LOA approval."}],"pvgbs":[]},{"id":41865,"option_order":2,"name":"Personalized ventilation system","description":"

At least 50% of workstations incorporate personalized ventilation systems that meet the following requirements:<\/p>","description_alt":null,"space_property":null,"certification":null,"note":null,"sub_part_id":32975,"deleted_at":null,"note_position_override":"top","verification_note":null,"verification_condition":"AND","requirements":[{"id":120310,"option_id":41865,"requirement_order":1,"description":"

One of the following strategies is implemented to efficiently deliver air to occupants:<\/p>\r\n\r\n

    \r\n\t
  1. Outdoor air is supplied in the breathing zone through vents incorporated into or mounted on furniture, and the return air diffusers within the space are located at least {{well-unit}}9 ft|2.8 m{{\/well-unit}} above the floor.10<\/sup><\/li>\r\n\t
  2. The system's zone air distribution effectiveness (E_z) is at least 1.20.10<\/sup><\/li>\r\n<\/ol>","description_alt":null,"deleted_at":null,"photographic_verification":0},{"id":120311,"option_id":41865,"requirement_order":2,"description":"

    One of the following strategies is implemented to support thermal comfort:<\/p>\r\n\r\n

      \r\n\t
    1. Outdoor air is supplied with an air speed of no greater than {{well-unit}}50 fpm|0.25 m\/s{{\/well-unit}} at the occupant's head.10<\/sup><\/li>\r\n\t
    2. The air speed from each outdoor air supply vent is individually controllable by occupants through a controller within the space, a mobile application or website.<\/li>\r\n<\/ol>","description_alt":null,"deleted_at":null,"photographic_verification":0}],"verifications":[{"id":11,"name":"Letter of Assurance \u2013 Engineer","chinese_name":"\u4fdd\u8bc1\u4e66\uff0d\u5de5\u7a0b\u5e08","is_auditable":0,"scale_type":"Shareable","note":"Project teams should complete all fillable fields in the PDF for LOA approval."}],"pvgbs":[]}]}],"on_sites":[],"annotated_documents":[],"letter_of_assurances":[],"part_guidances":[{"id":33098,"part_id":30685,"category":"WELL Core","sub_category":null,"rating_note":null,"alignment_note":null,"doc_guidance":"Meet these requirements in the whole building.","points":null}],"methods":[]}],"ihmes":[],"sdgs":[{"id":3,"name":"3: Good Health and Well-being","max_points":0}]}