high performance buildings: what are they?

NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

ASHRAE Region VI CRC

Paul A. Torcellini, Ph.D., PE

May 8, 2009

www.highperformancebuildings.gov

Tech Session 1: High Performance Buildings: What are They?

National Renewable Energy Laboratory Innovation for Our Energy Future

Buildings

39%

Industry

33%

Transportation

28% Residential

Commercial

Buildings use 70%of electricity

Heating 32%

Other 4%

Other 10%

Lights 28%

WaterHeat 13%

Computers 1%

Cooling 10%

Refrigeration 9%

Lights 12%

Electronics 5%Wash 5%

Cooking 5%

Heating16%Cooling

13%

Water Heat7%

Ventilation 7%

Cooking 2%Computers 3%

Office Equip 7%

21%

18%

Building Energy Use

Refrigeration 4% Source: 2004 Buildings Energy Databookwith SEDS distributed to all end-uses


Trend of Commercial Sector

5

10

15

20

25

30

1985

1990

1995

2000

2005

2010

2015

2020

2025

Sec

tor e

nerg

y (q

uads

)

0

5

10

15

20

GD

P (tr

illio

n $) Delivered

(site) energy

Total (source)energy

GrossDomesticProduct

Commercial Sector Energy Use is Growing at 1.6% per year

Growth is faster than energy efficiency measures


Zero Energy Buildings Goal

The U.S. Department of Energy’s (DOE) Building Technologies (BT) Program set a goal of creating the conditions for low- and zero-energy commercial buildings (LZEBs) to be market viable by 2025.

What is NREL?

A National Laboratory for the United States Department of Energy dedicated to working on Renewable Energy and Energy Efficient Technologies

www.nrel.gov


Preface

Remember the overall vision—reduce the impact of buildings.

Today’s building’s designs mortgage the energy future of this country.

Every design decision has an energy or environmental impact.

Definitions

What is a “sustainable” building?What is a “green” building?What is an “energy efficient building?”

Do we build energy efficient buildings today?What is the potential?

Vision

Many Pieces—Stressing the 3 year old

!


Many PiecesSo many ways to

assemble the pieces

Design is about making decisions –need motivation to make the right decisions


Setting Goals

Measurable goals are betterFrom bad to good…

– I want a green building– Design a LEED <rating> building– Design a building to use 30% less energy than

ASHRAE 90.1-2004– Design a building to use less than 30,000

BTU/sqft– Design a [NET] ZERO ENERGY BUILDING

Influencing purchasing decision—the owner

Goal

Setting Goals

• Need to establish goals that can be measured• People will strive to meet goals• Vague—I want a green building• Better—I want a building that uses less than X

amount of energy (such as 30,000 BTU/sqft)• Metrics is about measuring and comparison

• We will never have a perfect system for measuring--


Design is about making decisions

How do people make decisions?

Every Decision has implicationsIt is all about the process…

–What is cost-effective?–Economic–Operational reliability and power stability–Environmental Impact–Integrated the energy efficiency and architecture

Pre-Design Conceptual Design Design Development0%

100%

Form

Fabr

ic

Equi

pmen

t

Phases in the Design Process

Prog

ram

Des

ign

Dec

isio

ns

Influencing Design Decisions

Integrated DesignBetter application of existing technologiesIncreased efficiency of products

Energy usage is very diffuse


Easier, Cheaper to Make Design Decisions Early…

Time (Design Decisions)

Energy Use

Stages of Design Process

Pre-design

Conceptual Design

Construction

Operation

Architectural Design

HVAC/L DesignCode ComplianceHVAC Trade-offs/Sizing

Post Occupancy Evaluation

Goal Setting

Building Form/Fabric

Retrofit


Defining Scales

Percent Savings from Standard XMaintaining units—continuous scale

90.1-1999 Zero Site(by default)

30% AEDG


Defining Scales

90.1-1999 Zero Site30% AEDG Max. Potential“Carnot”

Advanced Energy Design Guides

Step towards NZEBAvailable as free download from www.ashrae.orgASHRAE/IESNA/AIA/USGBC joint projectPrescriptive approach for routine energy savings


Procedure

• Decide on the goals:– May be new construction targets– May be tracking and reducing current building

targets• Establish a long-term plan for measurement• Find a place to put the data

• Be careful of comparisons– CBECS

• US National Aggregated data• Big picture• Small scale comparisons can be misleading


DOE Commercial Building Benchmarks

• Standardized prototypical building models• DOE produced and published• 16 building types available• Can be used to represent building stock• Can be used to create more fine grained analysis• Best for comparison and trends


What is the Benchmark Project?

Project Goal:– Produce a set of building models and weighting factors that

represent ~ 70% of the commercial building stock for use in DOE building research

– Realistic building models • Look, construction, systems, operation

“Benchmark” Defined– Standard definition that represents “typical” buildings

suitable for whole building energy simulations

Joint Project: DOE, NREL, PNNL, and LBNL



Can We Build Low Energy Buildings?


Where we are today

Where we are if all buildings were built to code

Assessment potential


5967

6

43 4453 54

32

73

90 91

64

77

62

5

43

80

96

58

-10

10

30

50

70

90

All

Offi

ce/p

rofe

ssio

nal

War

ehou

se (n

onre

frige

rate

d)Ed

ucat

ion

Reta

il (e

xclu

ding

mal

l)Pu

blic

ass

embl

ySe

rvic

eRe

ligio

us w

orsh

ipLo

dgin

gFo

od S

ervi

ce

Heal

th C

are

Inpa

tient

Publ

ic o

rder

and

saf

ety

Food

sal

es

Heal

th c

are

(out

patie

nt)

Vaca

ntOt

her

Skill

ed n

ursi

ngLa

bora

tory

Refri

gera

ted

War

ehou

se

Subsector

Perc

ent s

avin

gs n

eede

d to

reac

h ZE

B g

oal

Percent savings from efficiency needed to reach ZEB

Need a 60 to 70 percent decrease on the Energy Consumption in commercial

buildings.


EE vs. RE

Typically less energy transfers, the betterBest to use energy produced on-site, rather

than exporting to another buildingRoughly 60-70 percent savings from EE with

30ish percent RE


58 kBtu/ft2-yr45

Base EUI

97%64%

% Savings Net


0

500

1,000

1,500

2,000

2,500

0% 100%Source Energy Savings (%)

Tota

l Ann

ual C

osts

($/y

ear)

Lease Costs (or Finance Costs)

utility bills

cash flow

1

The Path to a Net Zero Building

Typical 90.1 Compliant Building


00% 100%

Source Energy Savings (%)

Tota

l Ann

ual C

osts

($/y

ear)


utility bills

cash flow

1

2



00% 100%


Tota

l Ann

ual C

osts

($/y

ear)


utility bills

cash flow

1

23



00% 100%


Tota

l Ann

ual C

osts

($/y

ear)


utility bills

cash flow

1

23

4



Mor

tgag

e +

Ene

rgy

Cos

ts ($

/yea

r)


0

260

520

780

1040

1300

1560

1820

2080

2340

2600

0 10 20 30 40 50 60 70 80 90 100

~ 750,000 pts.(parametrics)

Zero Net Energy

Cross-Over Point

Energy Efficiency

On-Site Power(PV)

~ 750 pts.(optimization)

Energy + Lease C

osts

Parametrics / Optimization


Optimization Curve

Starting Point

Minimum Cost Point

Cost Neutral Point

Maximum Energy Savings

ZEB Not Possible

~3,000 Simulations

Goal

Goal

Strategies

Goal

Strategies

Goal

Strategies

Larger Projects

Larger Projects


Questions?

www.highperformancebuildings.gov