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8/7/2019 Displacement Ventilation in Schools
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Displacement Ventilation in Schools
www.price-hvac.com
8/7/2019 Displacement Ventilation in Schools
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Price Displacement Ventilation in Schools
www.price-hvac.com2
Occupied
Zone
Displacement VentilationMixing Ventilationx ng en a on
Introduction
Displacement Ventilation (DV) originated in industrial facilities in Europe as
an effective way to remove contaminants from the occupied zone. It has
since gained popularity in a variety of applications in both Europe and North
America due to its superior air quality, thermal comfort, and energy efficiency.
Mixing Systems Displacement Ventilation Benet o DV
55F supply air 65-68F supply airImproved thermal comort
and energy eciency
Mix the entire space No mixing in the space Improved indoor air quality
Diusers drive air motion
via high velocity supply air
Heat sources drive air motion
via thermal plumes
Improved thermal comort
and layout fexibility
Uniorm temperature Stratied temperature Improved thermal comort
Conditions entire roomOnly conditions the occupied
zone (the rst six eet o a space)
Improved energy
eciency
High supply velocity (minimum
150 pm 1 t rom ace)
Low supply velocity
(40 pm average at ace)Improved thermal comort
Displacement provides high temperature, low velocitysupply air, relying on the buoyancy orces o air to
drive air motion.
The result is high ventilation eectiveness and
improved thermal comort delivered in an energy
ecient manner.
Displacement diers rom traditional overhead mixing systems in several undamental ways:
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Indoor Environmental Quality (IEQ)
Displacement ventilation systems produce environments with extremely high
indoor environmental quality, producing the following IEQ benefits that are all
critical design criteria in schools.
Superior Air Quality and Ventilation Eectiveness
In DV systems, the supply air must pass through the breathing
zone beore being exhausted, because it travels rom a low
level to ceiling mounted returns. As it does this, it carries
contaminants away rom the occupant, leading to a high
ventilation eectiveness compared to mixing systems.
High Thermal Comort
DV delivers supply air at an average o 40 pm and at a
temperature no more than 10F cooler than the room air.
This high temperature, low velocity supply air results in less
drat and a lower percentage o people dissatised per
ASHRAE Standard 55-2010.
A Quiet Environment and Improved Acoustics
Displacement diusers distribute supply air at a very low velocity
into a room, resulting in whisper quiet operation.
Displacement
results in a high
ventilation effectiveness
(1.2 or higher) compared
to mixing systems (1.0
or below).
Displacement systems
typically achieve NC
levels of 15 to 20
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Beneits o
Improved IEQin Schools
Indoor Environmental Quality
(IEQ) has been proven by
several independent studies
to have a major impact on
the health, perormance and
attendance o students and
teachers.
Student Health
CHPS Literature Review:
Higher IAQ resulted in reduced asthma,
colds, fus, and headaches
CHPS Literature Review
CHPS Literature Review
Smedje and Norback, 2000
Smedje and Norback, 2000:
Swedish study o 39 schools over a two
year period
69% reduction in asthma or children
attending schools with displacement
systems
100 %
90%
80%
70%
60%
50%
40%
30%
20%
10%
100 %
90%
80%
70%
60%
50%
40%
30%
20%
10%
14%
12%
10%
8%
6%
4%
2%
0%
85.0%Cold
85.0%Cold
AustralianResidence
Liu et al1996
Jaakkda&
Miettinen1995
Wargocki1998
Brundageet al1985
Wieslanderet al1997
Frisk &Rosendfeld
1995
Frisk &Rosenfek
1995
Jaakkdeet al1994
Bourbeauet al1997
Sundell1996
BeigingResidence
Liu et al1996
Drinkaet al1996
61.5%Asthma,Allergies
67.0%SBS
47.0%SBS
46.0%Resipatory
23.6%Asthma
35.0%SBS
21.4%Asthma,Mucosal
33.6%SBS
33.0%SBS
20.0%Resipation
%I
mprovement/ReductioninSy
mptoms
%Improvement/ReductioninSymptoms
Pollen/petallergy
Asthmaever
Currentasthma
Any asthmasymptoms
More asthmasymptoms in95 than 93
New ventilation system
No new ventilation system
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Student Performance
Shaughnessy et al., 2006:
Studied the eect o ventilation rate on
student perormance in standardized testing
in 54 schools
Found perormance improvements in
classrooms with higher ventilation rates
Teacher Retention
Buckley, Schneider, and Shang, 2004:
Rated satisaction o 835 teachers in
89 schools based on IEQ
Improving satisaction with IEQ resulted in a 5%
increase in retention.
Shaughnessy et al., 2006
Shield and Dockrell, 2003Shield and Dockrell, 2003
Buckley, Schneider, and Shang, 2004
Shield and Dockrell, 2003:
Studied the relationship between classroom
noise and student perormance
21% test score improvement or students
with less than 50 dBA background noise
70%
60%
50%
40%
30%
110
100
90
80
70
60
50
40
Noise
Dirty or opaque windows
inoperable windows
Lighting
Temperature
Indoor air quality
48.7
56.3
47.7
61.8
50.6
64.4
53.3
64.5
Score
Ventilation Rate (I/s person)
Reading Math
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Applying DV in Schools
Displacement ventilation is a lexible method o air distribution that
can be used throughout an educational acility to improve air quality
and thermal comort, while saving energy and reducing utility cost.
Locker Rooms Classrooms Lecture Halls
Labs Libraries
Lobbies/Corridors
Oces
Kitchens/Caeterias
Gymnasiums
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Displacement Ventilation
in ClassroomsClassrooms orm a large portion o most buildings by square
ootage and are where students and teachers spend most o their
time. The indoor air quality, thermal comort, and low noise levels o
displacement ventilation make it ideal or this application.
These rooms are generally densely occupied or extended
periods o time, making minimizing drat and maximizing
usable space o primary concern.
Minimize Drat Zone
Use Price Room Designer sotware to test diuser layout
or thermal comort.
Integrate Diusers
DF1C corner mounted and DF1R recessed diusers are
excellent choices or maximizing usable space in aclassroom.
Custom diusers can be integrated into urniture and
millwork.
Improved Ventilation Eectiveness
The improved ventilation eectiveness o DV ensures that
students receive clean resh air sooner.
Air changes can be reduced without compromising air
quality to achieve energy savings.
Acoustics
Low noise levels are critical to a successul learning
environment. DV can help schools achieve classroom
noise levels under NC 20, resulting in improved
concentration and perormance.
Price DV Room Designer Sotware
DF1C
DF1R
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Sample Classroom Applications
1. Air Handling Unit
2. DR90 or DF1C corner
mounted diuser
Integrating diusers witharchitectural elements
maximizes usable space
3. DLE-H linear enclosure
with integrated heat
or perimeter heating requirements
1. Dedicated Outdoor Air System
2. DF1L lay-in displacement
diuser
Provides displacement cooling
while maximizing usable space
1
2
3
1
2
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DV in Auditoriums/Lecture Halls
The whisper quiet operation and superior air quality o displacement
make it ideally suited or densely populated auditoriums.
In addition, since only the occupied space is cooled, energy is not wasted cooling the signicant lighting
loads and large amount o space near the ceiling.
DF1W Wall Diusers integrate
seamlessly into the sidewall to save
foor space
RFDD or ARFHD Underfoor
Displacement Diusers provide
cool, resh air to the occupants romthe plenum beneath the foor
DV in Caeterias and KitchensDisplacement ventilation ensures that
clean, resh air is delivered to kitchen
and caeteria occupants, eectively
removing contaminants and odors.In the kitchen, the low velocity air does not disrupt the
unction o the exhaust hoods. The cooling load is also
decreased, as heat generated by cooking equipment
rises to the ceiling rather than being recirculated
throughout the room.
DR90 or DF1C Corner Diusers
adjust air fow to accommodate various
room loads
Right: Stainless steel DR90 diusers in a school kitchen
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DV in GymnasiumsDV in Gymnasiums
DV in Libraries
Similar to theaters, gymnasiums typically have high ceilings.
Conditioning these spaces with displacement cools only the
occupied zone, resulting in signiicant energy savings.
Libraries are oten mixed-use spaces
in schools, with areas or computer
use, book storage, reading, and
meetings. The ability to reconigure
the space quickly and economically
is o great value.
An access foor and underfoor air distribution oers this
fexibility, as diusers can be relocated quickly, oten without
having to modiy ductwork. Price oers several diusers that
combine the fexibility o UFAD with the superior air quality and
thermal comort o displacement, including RFDD and ARFHD
round foor diusers and DFG displacement foor grilles.
Diusers in gymnasiums
can produce higher ace
velocities, and typically
have upgraded
construction.
Price oers industrial grade diusers with heavy gauge aces capable o handling the abuse taken in a
gymnasium. These spaces can also tolerate a higher ace velocity
due to the high activity levels o the occupants.
Above: Price Displacement Ventilation
products installed in a library
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CHPS and LEED or SchoolsThe Collaborative or High Perormance Schools is a national K-12 green
school rating system in the United States whose goal is to improve student
perormance and educational experience by applying high perormance
building criteria and the best possible building technology to schools.
Collarborative or High Perormance Schools (CHPS)
CHPS recommends Displacement Ventilation as the preerred air distribution method
and awards up to 4 CHPS points or its use.
Leadership in Energy and Environmental Design (LEED)
The United States Green Building Councils Leadership in Energy and Environmental
Design (LEED) program has a rating system specically designed or schools or which
displacement ventilation can earn points.
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Price Displacement Ventilation in Schools
Sotware Tools
Room Designer or Displacement
Ventilation
Our revolutionary Room Designer or Displacement
Ventilation allows a designer to select and lay outPrice displacement diusers based on drat risk
comort data.
The sotware calculates comort using ASHRAE
ormulae based on local air temperature and local
air velocity, responding in real-time to diuser
placement.
The sotware is specically designed to
accommodate school design criteria, including
ventilation rates.
Visit www.price-hvac.com/Sotware/
Roomdesigner to download Room
Designer today!
All-In-One Selection Sotware
Prices All-In-One Selection sotware allows an
engineer to perorm air volume calculations,
evaluate system perormance and select products,
including displacement ventilation diusers, with
speed and accuracy.
Visit www.price-hvac.com/Sotware/AIO/ to
download All-In-One today!
Price oers the best sotware tools in the HVAC industry or selecting
and evaluating displacement ventilation diusers as they apply to
schools.
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Price Engineers HVAC Handbook
The Most Comprehensive Guide to
HVAC Fundamentals
The Price Engineers Handbook is a compilation o the
engineering knowledge related to the application o air
distribution and noise control products and approaches
gained at Price over the past 60 years.
The Handbook contains chapters on Displacement
Ventilation and its applications, including liberal use o
examples and graphics to help illustrate and explain
concepts and systems.
Chapter 15: Displacement Ventilation
Chapter 16: Applications o
Displacement Ventilation
Contact your local Price sales representative to reserve
your copy.
Price Sustainable Building Website
The Price Sustainable Building Website is the ultimate
online resource or those looking to learn more about
sustainable HVAC technologies like displacement
ventilation.
The site eatures:
Product Inormation
Research Papers
Case Studies
Training Modules
Smoke Test Videos
Product Videos
Visit www.price-hvac.com/sustainable today!
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Resources and SupportPRCN: Price Research Center North
Prices state-o-the-art research laboratory, Price Research Center North, eatures the most advanced
displacement fow visualization chambers, testing acilities, and mock-up rooms in North America.
Flow visualizations and mock-ups allow designers to simulate eld conditions and evaluate system
perormance giving them condence that their space will perorm as expected in the eld.
Ask about our mock-up services on your next job, or better yet,
visit PRCN yoursel and tour the acilities.
Computational Fluid Dynamics Modeling
CFD provides a means to validate design beore
construction and gives condence that the system
will perorm as intended in the eld. Price has an
experienced and procient CFD team and we
encourage designers to work with us to validate
their designs.
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Applications Support
Price is a service oriented company and has a
dedicated Displacement Ventilation applications
team devoted to answering your questions quickly,
completely, and correctly. We are here to help!
Our applications team regularly provides
support on:
Model Selection
Layout Assistance
Calculation Assistance
On-site Training
On-site Perormance Validation
Price Training Programs and Webinars
The Price Training Programs (PTP) provides
Consulting and Design Engineers with the training
needed to speciy and select air distribution
equipment to best meet their design criteria. The
displacement course covers everything you need
to know about displacement products, including:
Overview o DV
Theory and Design Considerations
Displacement Products
PRCN and Engineering Support
Our webinars are another excellent way to learn
about specic topics while gaining proessional
development hours.
Visit www.price-hvac.com/ptp to register today!
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Grilles & Diusers CriticalEnvironments
Terminals &Controls
SustainableBuilding
Noise Control
www.price-hvac.com Price is a registered trademark of Price Industries Limited. 2011. Printed in Canada 2011
Canadian Head Office
Price Research Center North International Sales Office
Winnipeg Manufacturing Facility
U.S. Head Office
Price Technical Center
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Atlanta Manufacturing Facility
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Phoenix Manufacturing Facility
Toronto Manufacturing Facility
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999 North Thornton Road
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130B Pippin Road
Vaughan, Ontario Canada L4K 4X9
2975 Shawnee Ridge Court
Suwanee, Georgia USA 30024
Ph: 770.623.8050 Fax: 770.623.6404
638 Raleigh StreetWinnipeg, Manitoba Canada R2K 3Z9
Ph: 204.669.4220 Fax: 204.663.2715
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