ASSESSTARGETDELIVER

MEASURE

Understanding Building Energy Audits

Joe Hofstetter P.E., CEM, LEED APKarpinski Engineering

Terms

• ASHRAE – American Society of Heating Refrigeration and Air-Conditioning Engineers

• AEE – Association of Energy Engineers• PEA – Preliminary Energy-use Analysis• ENERGY AUDIT/ASSESSMENT – An overall study of building

operation, energy end-use, and energy consuming equipment over a specified period of time.

• ECM – Energy Conservation Measure• IPMVP – International Performance Measurement and

Verification Protocol• RETRO-COMMISSIONING (RCx) – Capturing an existing

building’s owners requirements, and putting a plan in place to identify, resolve and document that these requirements are being met

Getting Prepared

Selecting the Right Tool

Length of Time

Level of Detail

Reason for Audit

What questions do you need to be prepared to

answer?

Types of Audits

LEVEL IIILEVEL IILEVEL IACCURACY

COST

Audit Process

Conduct PEA

Conduct Initial Walk through

Initial onsite interviews

LEVEL IIILEVEL IILEVEL I

Audit Results

Identify straight forward or low cost recommendations

Identify capital improvement needs

Provide order of magnitude potentials based on benchmarking and targeting

LEVEL IIILEVEL IILEVEL I

Audit Results

Preliminary Scopes of work with Cost Estimates

Detailed energy calculations for specific ECMs

Listing of improvement measures with payback

Audit Process

Review building documents and conduct detailed interviews with facilities

Measure key parameters

Detailed interviews with facilities and Analyze capital/O&M budgets

LEVEL IIILEVEL IILEVEL I

Audit Results

More detailed scopes of work

Total building energy modeling (impact of multiple ECMs working together)

Schematic layouts for recommendations

Audit Process

Energy Model simulations

Extended time equipment monitoring / data logging

Refined analysis

Preliminary Energy-Use Analysis

Preliminary Energy-Use Analysis

Combined Fuel End-Use Breakdown

Field Work and Measurement Tools

• Thermography testing• Basic level equipment testing

and balancing• Measurement tools for trending

Modeling

The interaction between

improvement measures can have a significant impact

on the overall building

performance

Types of Improvements

• Lighting upgrades

• Building management systems

• System controls

• Water conservation measures

• Chiller and boiler optimization upgrades

• Renewable energy

• Building envelope Improvements

• Site engagement programs

• GHG reduction planning

• Master energy planning

• Fans, air distribution and A/C

• Central plants

• Computer power management

• Fire & safety systems

• LEED certification

• Electrical demand response

• Electrical load shedding

Average Cost of Auditing

• Level 1 Audit = Free to $0.05 / Square Foot

• Level 2 Audit = $0.10-$0.15 / Square Foot

• Level 3 Audit =$0.25-$0.50 / Square Foot

As a rule of thumb, typical auditing services should not exceed approximately 10% of the total annual energy spend

ECM Sheet

Life Cycle Analysis

Setting Up for Success

• What’s our payback?• How fast do we want to

implement?• What other factors can be

considered that ECMs may impact both positive and negative?

• How will the project be funded?

• Will the implementation of these services interrupt the flow of business?

• Do I need my savings to be guaranteed?

• How do I explain “savings” when my utility bill goes up?

TARGET

DELIVER

MEASURE

QUESTIONS?