indoor air quality and occupant satisfaction in green...
TRANSCRIPT
Asst. Prof. Dusan Licina, Ph.D.
School of Architecture, Civil and
Environmental Engineering
École polytechnique fédérale de Lausanne
Human-Oriented Built Environment LabWebsite: hobel.epfl.chTwitter: @licinadusan
INDOOR AIR QUALITY AND OCCUPANT
SATISFACTION IN GREEN CERTIFIED BUILDINGS
A Pilot Case Study
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Specific research areas
POLLUTANT DYNAMICS IN INDOOR AIR
HUMAN AIR POLLUTANT EXPOSURE
AIR QUALITY AND COMFORT IN BUILDINGS
SMART VENTILATION
AND IOT
3
• Currently, there are more than 200 different green building
certification programs around the globe.
Around 1 million green certified projects
4
Current state of knowledge
• Few detailed studies on IEQ in green buildings
• Most (but not all) research shows that green buildings
outperform conventional ones in relation to IAQ and
reported satisfaction
• We need much more evidence to conclude this
• Little research has been conducted to determine whether and
how elements of green building programs improve IAQ
5
New directions – designing for “health”
• Recent shift in design to emphasize the health and
experience of occupants – so called “Healthy Buildings”
• None of previous studies have investigated a green rating
scheme that focuses solely on “human health”, such as
WELL and LBC.
• WELL is the fastest growing green (“healthy”) building certification
program
(Source: https://v2.wellcertified.com/v/en/overview)
A separate talk about WELL starts in 40 min
By Veronika Licina
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Three case studies: “Before” and “After”
BREEAM
Winter 2019
WELL
Summer 2019
WELL
Winter 2020
RELOCATION
COMMON
Summer 2019
WELL
Winter 2020
WELL
Summer 2020
COMMON
Summer 2019
WELL
Winter 2020
WELL
Summer 2020
CA
SEST
UD
Y 1
CA
SEST
UD
Y 2
CA
SEST
UD
Y 3
7
Case study 1: BREEAM vs WELL
BREEAM Building WELL Building
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Methods – Physical measurements
• Amsterdam, ~450 employees
• Physical measurements: 1 month per season
• Open space office, meeting room, private office
• Active: CO2, T, RH, size-resolved PM (0.3-10 µm)
• Passive: Individual VOCs, aldehydes
BREEAM
Winter 2019
WELL
Summer 2019
WELL
Winter 2020
RELOCATION
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Methods – Subjective surveys
very
satisfied
satisfied neutral dissatisfied
slightly
dissatisfiedvery
dissatisfied
slightly
satisfied
• Collected responses:
• 202 BREEAM (pre-relocation)
• 203 WELL (post-relocation)
• Questions about IEQ satisfaction/ perception/ preference,
building-related symptoms, self-reported productivity
• Statistics: Wilcoxon rank sum test (Mann-Whitney test)
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BREEAM vs WELL: CO2 and PM10
• Generally acceptable levels of CO2 and PM10 in both
buildings
Level of CO2 slightly lower in
WELL, owing to lower
occupancy density
Similar level of PM10 in the
two buildings
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BREEAM vs WELL: T and RH
No difference in T, despite
different seasons
Low RH level in BREEAM,
owing to seasonal effects
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BREEAM vs WELL: VOCs
Low VOC level in BREEAM-
certified building
Elevated level of “special
indoor”, especially Ethanol, 2-
(2-butoxyethoxy)-, acetate
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BREEAM vs WELL: TVOC & formaldehyde
Nearly order of magnitude
higher TVOC level in WELL
Higher level of formaldehyde
in WELL building
• Generally acceptable levels of formaldehyde, but TVOC
level in WELL exceeds German standard limit values
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BREEAM vs WELL: IAQ and Thermal Comfort
• Despite significantly lower level of TVOCs and formaldehyde
in BREEAM, employees were more satisfied with IAQ in
WELL-certified building
• Higher level of thermal comfort in WELL building
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1 2 3 4 5 6 7
Thermal comfort
Thermal comfort_W
Indoor air quality
Indoor air quality_W
Amout of l ight
Amout of l ight_W
Visual comfort
Visual comfort_W
Noise level
Noise level_W
Sound privacy
Sound privacy_W
Building maintenance
Building maintenance-W
Workplace
Workplace_W
Buildings
Buildings_W
ENVIRONMENTAL FACTORS
BUILDING
WORKPLACE***
BUILDING MAINTENANCE
SOUND PRIVACY***
NOISE LEVEL***
VISUAL COMFORT**
AMOUNT OF LIGHT
INDOOR AIRQUALITY***
THERMAL ENVIRONMENT***
-3 -2 -1 0 1 2 3VERY DISSATISFIED
VERY SATISFIED
BREEAM Building (n=202)
WELL Building (n=203)
MedianMean
v
1 2 3 4 5 6 7
Thermal comfort
Thermal comfort_W
Indoor air quality
Indoor air quality_W
Amout of l ight
Amout of l ight_W
Visual comfort
Visual comfort_W
Noise level
Noise level_W
Sound privacy
Sound privacy_W
Building maintenance
Building maintenance-W
Workplace
Workplace_W
Buildings
Buildings_W
ENVIRONMENTAL FACTORS
BUILDING
WORKPLACE***
BUILDING MAINTENANCE
SOUND PRIVACY***
NOISE LEVEL***
VISUAL COMFORT**
AMOUNT OF LIGHT
INDOOR AIRQUALITY***
THERMAL ENVIRONMENT***
-3 -2 -1 0 1 2 3VERY DISSATISFIED
VERY SATISFIED
BREEAM Building (n=202)
WELL Building (n=203)
MedianMean
v
• Satisfaction level with several other IEQ-related factors was
higher in WELL compared to BREEAM
BREEAM vs WELL: Other IEQ
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WELL* vs. all others
* Small
sample size
Contact: [email protected]
The first ever study to examine WELL-certified building
No significant difference in CO2, T and particle levels
Indoor VOC level higher in WELL than in BREEAM
building
Occupants seem to be more satisfied in WELL than
BREEAM and other green-certified buildings
Need to conduct a broader research effort
We are currently investigating a larger sample of WELL
buildings
Summary of a case study
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Overview of building practices
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Discussion - Health performance pyramid
(Source: Licina et al. 2019, ASHRAE Journal)
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Challenges of green buildings – Challenge 1
(Sources: Licina et al. 2019, ASHRAE Journal; Teichman et al. 2015; Wei et al. 2015 BAE; LEED V4)
• Significant gap between relative emphasis on energy
related features and those that focus on occupant health
• A review of 100 green building case studies suggested that the
most prevalent energy saving strategies were observed in 80% of
green buildings, while high indoor air quality was reported in much
less buildings
• Low credit percentage
related to IAQ/IEQ
• LEED: now 20%,
it used to be 15%)
• All programs:
only ~7.5%
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Challenge 2: Performance testing/verification
(Sources: Licina et al. 2019, ASHRAE Journal)
• Most existing green building standards lack established
protocols for performance testing:
• The most rigorous IEQ verification practice is available in the
latest version of the WELL v2, but…
• For a 5’000 m2 project, 5 floors: 3 locations, once 1-hour of 1-
min measurements. Valid for 3 years!
• Episodic, resource-intensive, expert operator
• Early experiments with IoT sensing
• WELL v2 A08: Continuous monitoring once every 10 min, every
325 m2
• WELL v2 A07: Operable windows; monitoring once every hour,
acceptable within 4 km of a building
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Challenge 3: Lack of health metrics
(Sources: Licina et al. 2019, ASHRAE Journal)
• There is a lack of metrics to define leadership
• No established health-based indoor guidelines
• Most indoor guidelines are simply copy/paste of outdoor
guidelines
• The challenge is that our environmental health knowledge is
incomplete! So far only limited exposure data available with
fragmented data on health consequences…
Green buildings are often assumed (or claimed) to be
healthy and beneficial for occupants, but without the
performance data to support such claims/aspirations !
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Challenge 4: Knowledge on green buildings
(Sources: Licina et al. 2019, ASHRAE Journal;
Colton et al. 2015 American Journal of Public Health)
• Most (but not all) research shows that green buildings
outperform conventional ones in relation to measured and
perceived air quality and reported satisfaction
• We need much more evidence to conclude this, especially for health
Energy and Water Conservation
Occupancy Surveys
Indoor Environmental Quality
Direct Evidence for Health
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There is much to be achieved!
UnacceptableSick Buildings
SufficientTypical Buildings
EnrichingGreen Buildings
DesiredHealth and well-being