…and High Performance Buildings

Advanced Energy Design Guide

LEED Strategies for Schools

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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Chapter 3

Climate Zone Map

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Chapter 3

Recommendation Tables

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HVAC

SYSTEMS

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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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HV-1

Packaged (or Split) DX Units

Climate Zone 2

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Climate Zone 2

HV-6

Chilled Water VAV Systems

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Chapter 5

“How To” Tips

Good design practice

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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-12

Dedicated OA Systems

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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

RA

OA

S

A

tooccupiedspace

from occupiedspace

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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

LEED for Schools35 35

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

LEED for Schools36

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

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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

LEED for Schools43

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?

LEED for Schools47

THANK YOU!