making building systems sing in harmony retrocommissioning

Making Building Systems Sing in Harmony

Retrocommissioning in Vermont

Daniel Tuhus-Dubrow

Cx Associates

Presented by:

Agenda

What is Retrocommissioning?

The RCx program in Vermont

RCx Process

Common RCx Findings

Case Studies

Challenges and Opportunities

Retrocommissioning is…..

Process for ensuring systems and equipment are operating per the current facility requirements

Repairing Deficiencies

Optimization of Existing Building Operation

Measures are typically low or no cost to implement

Retrocommissioning is…..

Other Potential Benefits Operations and Maintenance Occupant Thermal Comfort Improved Indoor Air quality

Retrocommissioning is NOT…..

Capital improvement projects:

However… Equipment at the end of its useful life will often be identified through the RCx process.

Lighting retrofits

Equipment replacement

Window upgrades

Reducing Greenhouse Gas Emissions

Commercial buildings consume nearly half of the building energy used in the United States (around 20% of total U.S. energy consumption and greenhouse gas emissions)

RCx Potential

Saving Money

Median whole building energy savings of 16%

Median cost of $0.25 per sf

Median payback time of 1.1 years

RCx Potential

The RCx Program in Vermont

Programs from Efficiency Vermont and BED

Qualify Develop Implement Verify

Steps in Qualifying Phase

Pre-qualify

Walkthrough by team

Findings and Recommendations

Estimate energy savings

Development Phase

Document Baselines

Refine Savings Estimates

Develop Scopes of Work

Obtain Pricing for Implementation

Implementation Phase

Pay for performance

$0.10/kWh up to $25,000

Vendors implement recommendations

RCx Process

Building Energy Benchmarking

Review Available Documentation

Utility Data Analysis

Site Visits and Field Investigations

Trend Data Analysis

Measure Development

Implementation

Benchmarking

Energy Star Portfolio Manager

DOE Building Performance Database

Benchmarking

Building Documentation

Mechanical/Electrical Drawings

Controls Drawings

TAB reports

Previous energy assessments

Utility Data Analysis

Monthly Bills

Electric Interval Data

Delivered Fuels

Utility Data Analysis

Interval Data Analysis

Opportunity to Adjust Operating Schedule?

Interval Data Analysis

Interval Data Analysis

Occupied Baseload

Cooling Balance Temp

Cooling Demand

Interval Data Analysis

0 25 50 75 100

Site Visits

Meeting with Key Stakeholders

Systems Assessment

Datalogger Deployment

Targeted Testing

Kickoff Meeting

Teamwork

Have the

right people!

Team

Commissioning Engineer

Controls Contractor

Facilities Staff

Introduce Perspectives

Brainstorm

Identify Opportunities

Evaluate Merit

Building Walkthrough

Systems Assessment

BAS Remote Monitoring

BAS Remote Monitoring

Dataloggers

Trend Data Analysis

Verify existing control sequences

Are setpoints being maintained?

Is economizer operating properly?

Are resets working as intended?

Is equipment running per schedule?

Trend Data

Analysis

Spreadsheet based charting

Universal Translator

Dedicated analytics software

Other Tools

Trend Data Analysis

Trend Data Analysis

Methods for Estimating Savings

End Use Disaggregation

Engineering Calculations Bin Calcs Hourly Spreadsheets

Regression Models

Energy Simulation

Common RCx Findings

• Scheduling

• Economizer Operation

• Simultaneous heating and cooling

• Calibrating or relocating sensors

• Return Equipment to AUTO control

• Release BAS Overrides

• VAV box minimum flow settings

• Correct VFD settings

• Optimize Control Sequences

Operating Schedules

Throttled Valves

Stuck Dampers

Equipment Overrides

Damaged Sensors

Measure Development

Document baselines

Focused PFCs and FPTs

Refine savings estimates

Develop scopes of work

Obtain pricing

Project Case Studies

Building Types Hospitals Universities K-12 Schools Office Buildings Ski Resorts Food Processing Municipal

Projects Overview

N = 28 6,000 – 200,000 sf Median = 34,800

Projects Overview

> $350,000 potential savings 0.5 – 4.5 years Median = 1.9

Hospital AHU Optimization

Measure Summary

Dehumidification setpoints unnecessarily low (40-45%)

Economizer lockout setpoints unnecessarily low

Economizer controlling to MAT setpoint rather than SAT setpoint

Implement static pressure reset

Enable supply air temperature reset

Used Guideline 36 recommendations where possible

Verify calibration of controlling sensors

Unnecessary filters with higher efficiency than required

Hospital AHU Optimization

Pre Post

Challenges

Getting to Implementation Measure Persistence

Implementation

Facility buy-in

EVT / BED involvement

Incentives help

Measure Persistence

Training is KEY

Post-Implementation BAS Monitoring

Establish continuous energy improvement program

Opportunities

LARGE MARKET POTENTIAL

ONGOING COMMISSIONING

ENERGY MANAGEMENT INFORMATION

SYSTEMS

Ongoing Cx

Thank You!

Daniel Tuhus-Dubrow

Senior Engineer

Cx Associates

Burlington, VT

802-861-2715 x21

daniel@cx-assoc.com