LEED for Schools2
Today‟s Presenters…
Stephen Koontz, LEED APEnergy Services Leader
Tampa Bay Trane
Allen IrvineGeneral Sales Manager Central & North Florida Trane
Teri BortonComprehensive Solutions Leader
Gulf South Trane
Tracy HendersonAccount Manager
Gulf South Trane
LEED for Schools3
What you will learn today
„HOW TO‟ Tips
Strategic Examples That Assist with LEED for Schools
Resources Available to Assist with Designing Energy Efficient School & College Facilities
...
LEED for Schools4
ADVANCED ENERGY DESIGN GUIDES
Collaboration of:
AIA
ASHRAE
CHPS
IESNA
NCEF
SBIC
USGBC
U.S. DOEwww.ashrae.org/freeaedg
LEED for Schools5
Advanced Energy Design Guide
for K-12 School Buildings
www.ashrae.org/freeaedg
http://www.trane.com/Commerci
al/SystemPortFolio.aspx
LEED for Schools6
AEDG FOR K-12 SCHOOL BUILDINGS OVERVIEW
Climate-specific recommendations to achieve 30% energy savings
“…intended to show that achieving the 30% target is not only possible, but
easy.”
Promotes off-the-shelf technology
(no special expertise to design/install)
Addresses whole building and the interaction of sub-systems (envelope, lighting,
HVAC, service water heating)
Eliminates need for energy modeling by providing prescriptive path to energy
savings
LEED for Schools7
LEED®
FOR SCHOOLS
can be used to achieve four points under Energy and Atmosphere Credit 1
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4b
SmallPackagedRooftops
UnitVentilators
Water-sourceHeat Pumps
K-12 PRESCRIPTIVE HVAC RECOMMENDATIONSWhich Type of HVAC System?
Chilled-waterVAV
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Prescriptive recommendations forSix HVAC System Types
HV-1: Single-zone, packaged DX units (or split DX
systems)
HV-2: Water-source (or ground-source) heat pumps with
dedicated OA system
HV-3: Unit ventilators with water chiller and boiler
HV-4: Fan coils with water chiller and boiler and
dedicated OA system
HV-5: Multiple-zone, VAV packaged DX rooftop units
HV-6: Multiple-zone, VAV air handlers with water chiller
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climate-specific and system-specific
Recommendation Tables
Unique recommendations are included for each HVAC system type in the climate-specific tables in Chapter 3
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climate-specific and system-specific
Recommendation Tables
Some system types are not recommended for certain climate zones because of the impact of humidity on energy use
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Chapter 5
Good Design Practice
Load calculations
Dehumidification
Energy recovery
Equipment efficiencies
Ventilation air
Dedicated OA systems
Economizer
Demand ventilation
Exhaust air systems
Fan motor efficiencies
System-level controls
Chilled-water system
Hot-water heating
Thermal zoning
Filters
Duct design, construction
Duct insulation
Duct sealing, leak testing
Air balancing
Commissioning
Relief versus return fans
Heating sources
Noise control
Proper maintenance
Zone temperature control
Operable windows
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HV-10HVAC Equipment Efficiencies
Recommended efficiencies based on:
Climate zone
HVAC system type
System size (capacity)
Fuel type (electricity or natural gas)
for climate zone 5
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HV-11Ventilation Air
Determine based on ASHRAE 62.1 Use actual occupancy
for calculations,
not exit population
Use population diversity (D)
when using multiple-zone
recirculating systems
Use time-of-day schedules
to introduce ventilation air
only when a zone is
expected to be occupied
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climate-specific and system-specific
Recommendation Tables
Because conditioning OA for ventilation is such a big contributor to energy use in schools, eitherexhaust air energy recovery or demand-controlled ventilation (DCV) is recommended.
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HV-9
Exhaust-Air Energy Recovery
50% total effectiveness for
“A” (humid) climate zones
50% sensible effectiveness for
“B” (dry) climate zones
Integrate control with airside economizer and provide
bypass dampers
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HV-14
Demand-Controlled Ventilation
Vary amount of OA introduced by:
Time-of-day schedule in BAS
Occupancy sensor
Carbon dioxide (CO2) sensor
Use in densely-occupied zones with highly-variable
population
Cafeteria
Auditorium
Conference Rooms
Vary amount of exhaust air to prevent negative building
pressure
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HV-8
Part-Load Dehumidification
Design system to minimize number of hours that space
relative humidity remains above 60%
Recommends methods for improving part-load
dehumidification (by HVAC system type)
For Chilled Water VAV System:
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HV-25
Chilled-Water Systems
Design for variable flow (except for very small systems)
Use a chilled water T of 12–20°F
Low flow/Low Temperature/High Delta T System
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Proper Maintenance
Neglecting preventive maintenance practices can quickly
negate any energy savings expected
Filters should be
replaced regularly
ERVs need to be
cleaned periodically
Dampers, valves,
louvers, and sensors
must all be periodically
inspected and calibrated
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Commissioning
Selection of
commissioning
authority
Include commissioning
activities in the
project schedule
Recommended
commissioning
activities
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Advanced Energy Design Guide
for K-12 School Buildings
www.ashrae.org/freeaedg
http://www.trane.com/Commerci
al/SystemPortFolio.aspx
LEED for Schools30
LEED Strategies
1. Capture and Reuse Condensate
2. Exhaust Air Energy Recovery
3. Thermal Energy Storage
With Low temperature chilled water system
4. Scheduled and/or Demand Based Ventilation
5. Commissioning
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Capture and Reuse Condensate
High School in Tampa, FL
1,000 Students
15 CFM/Person
OA
H20
SA
15,000 CFM
855,000 Gallons
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Capture and Reuse Condensate
Cooling Tower
Condensate Water is Cold – Reuse Energy
Condensate Water is Clean – Lowers Chemical Treatment
Replaces Potable Water for Cooling Tower Make-Up
Wastewater Conveyance
Irrigation
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Uses “Off Peak” Energy Rates
Smaller Cooling Equipment- Less Refrigerant
Reduce Power Plant Source Energy, Emissions and Need to Build
Increase Operational Flexibility
Achieves LEED Points by Reduce Energy Cost Over a Baseline
Building ( E+A Up to 10 Possible Points)
BENEFITS OF THERMAL ENERGY STORAGE
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Conventional Design
High School
Hybrid Design
High School
296,375 ft2 1,800 students
428 kW Peak
Energy Star Rating 87
1.44Watts / ft2
$118 / ft2
$32,000 Less spent on Electricity
288,192 ft2 1,800 students
800 kW Peak
Energy Star Rating 48
3 Watts / ft2
$120 / ft2
TES COOLING LEED™S TO RESULTS
http://leedcasestudies.usgbc.org/overview.cfm?ProjectID=672
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Seminole Community College
• 12/21/05- 15 year Performance Contract $3.6 million
Annual Guaranteed Savings
$365,449
24 Tank Ice Storage Plant No Demand Charges
“Off-Peak” energy rates
Utility Rebate
PROJECTS THAT WORK
LEED for Schools37
Consider Thermal Energy storage if…
Utility has “on-peak” or “off-peak” rates (rebate)
Peak load is higher than average load
Peak demand is higher than average demand
Existing system is being expanded
Backup or redundant cooling is desired
Cold air distribution is desirable (Lower humidity, smaller
pipes, smaller ductwork)
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T T
RH VAV
RA
RH VAV
Demand Control Ventilation
classroom classroom
OSAUOA
OS OS
lightingpanel
ControlSystem
CO2CO2
relief air
OA VAVOA VAV
AHU
OSAU – Outside Air Unit AHU – Air Handling Unit
OA VAV- Outside Air VAV Box RH VAV – Reheat VAV Box
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VAV Systems/ Demand Controlled Ventilation
Benefits Include
Reduces energy use
Lowers operating cost
Delivers appropriate amounts of fresh air
Humidity control
Healthier and more productive learning environment
Improves occupant comfort, health, and productivity
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Pensacola Junior College
Installed Sensor Controlled Outside Air
Ventilation
For non-densely occupied spaces, use CO2 sensors to signal system to
provide appropriate amount of fresh air in classrooms
Calibrate controls so that outside air damper modulates to maintain
appropriate CO2 levels
Adjust fresh air intake to eliminate conditioning of excess outside air
while ensuring a positive pressurized building
Pensacola Junior College
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Results
VAV and Demand Control Ventilation strategies projected
to save $142,000 annually
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Fundamental Commissioning (Cx)
Intent Verify energy related systems are installed and calibrated and operate
according to:
– Owner‟s project requirements
– Basis of design/construction documents
Requirements
Minimum - HVAC and controls; lighting and daylighting controls;
domestic hot water; and renewable energy (wind and solar)
Encouraged - Water-using systems and building envelope
Commissioning Authority (CxA) reports to Owner
Benefits Include
Reduced energy use
Lower operating cost
Reduced contractor call backs
Improved occupant productivity and health
Pre-requisite for LEED Certification
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Retro-Commissioning of HVAC Systems
Chipola College
Campus consisted of 6 buildings with older generation
building control system
No commissioning of HVAC systems since original
construction
Utility price increase was forthcoming
Decision made to re-commission HVAC systems to
optimize energy usage
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Strategy at Chipola College
Activate controls software features and upgrade
system to newest generation
Time of Day programming eliminated 24/7 usage
Unoccupied cooling and heating set points
Optimal Start/Stop to reduce HVAC system run time
Staggered start eliminating peak usage charges
Modify building components to eliminate excess
energy usage
Adjusted Outside Air (OA) intake to eliminate conditioning
excess OA while ensuring positive pressurized building
Optimized chilled water bypass
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Results
$38,000 first month energy savings
Sustained savings of $30,000-$40,000 monthly
No increase in utility costs even with increased rates
Improved comfort of students and staff
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“With budget cuts, we can’t afford to install the highest
efficiency HVAC and control systems for our new building.”
Hmmm.…How can you afford
NOT to?
What is the true cost of ownership?