netapp building 4 pilot project -...

NetApp Building 4

Pilot Project

Accenture Smart Building Solutions (ASBS)

1 Copyright Accenture 2012.

Copyright Accenture 2012. 2

Objectives

Building Profile and BMS Profile

Analysis and Improvements

Agenda

Costs Savings Opportunities

Impact of Interventions

Appendix

Objectives

Why ASBS?

ISO 14001 Target Objective to reduce energy consumption

Discover hidden savings opportunities

Optimize equipment operation

Make incremental improvements to already efficient buildings

Reduce building drift that occurs over time

Leverage existing instrumentation to make buildings Smarter through

analytics

3 NetApp Confidential

NetApp Building 4


Building Profile

121,185 sf. 3-Story Class A office building

Constructed in 2004

2 mW Engineering Lab

$2.7 Million/year energy spend

Energy Star Building

Chilled Water Plant

Lighting Controls/Day-lighting

CO2 Monitoring

Good Instrumentation – A data rich environment

BMS Controls

~ 33,000 BMS points

5,147 BACnet Points

2 - Main Service Entrances, 2 main meters with PQ

35 submeters, 9 points/submeter

2 - 600 Ton Chillers, 41 points/Chiller

2 Roof Top AHU’s, 12 points/AHU

50 VAVs, 5 points/VAV

18 CRAH’s, 10 points/CRAH

218 points/VFD

15 zone dampers, 8 points/damper

Used Gateway to push BACnet data

Used XML SOAP to push Non-BACnet points


Operational Improvements in AHUs


Through the following AHU improvements we have decreased the warm-up period by

~50% 1) Increased unoccupied SAT - Closing outside air damper when building is unoccupied

2) Increased SAT in AHU2 to match AHU1 - Calibrated dampers and sensors to adjust control and outside air leakage

3) Increased maximum SAT - Increased max SAT setpoint

4) Increased heating input to AHUs - Matched boiler run time to AHU supply fan enable time

5) Reduced instability in RAF - Loop tuned to not be so sensitive to small pressure changes in the building

1 1

2 2

3 3

5 5

4 4

Chiller Analysis Results

Both chillers in Building 4 are operating at efficiencies 40% below

manufacturer specifications

The NetApp chillers require ~42% more electricity then specified in manufacturer

ratings (0.68 vs 0.48 kW/ton at 72% load).

Chiller efficiency is below specification even when operating with a load well below the

rated capacity (which should make the chiller more efficient).

Both chillers in Building 4 are operating with a evaporator flow from 20% to 30% above

the chillers’ design flow. This is likely causing the chiller refrigerant pressure in the

evaporator tube bundle to exceed manufacturer specification.

Unstable chiller load due to cycling of the CRAH cooling valves was a likely contributor

to this issue.


Operating Parameter Manufacturer

Specification

NetApp Operating

Conditions

Evaporator Pressure (PSI) 39.5 36.4

Condenser Pressure (PSI) 74.6 87.2

Difference 35.1 50.8 (1.45 X Base)

Impact of ASBS Recommendations to Date


The interventions identified by the ASBS service have significantly improved

the performance of the HVAC system in Building 4.

Accomplishments

Decreased the building’s required warmup time by ~50% (between 2-4 hours reduction

per day, depending on outside air temperature)

Coordinated separate systems to drive efficiency (Boiler and AHU schedules)

Identified malfunctioning components (AHU economizer actuator)

Reduced cycling and instability of controls logic (FCU cooling coils, AHU return fan)

Contributed to best practice in BAS setup and controls logic across other NetApp

buildings

Identified limitations of the current controls system setup (PID loops for VAVs, Chiller

supply temperature, AHU individual control, etc.)

Overview of Recommendations to Date


2) Implemented to support reducing simultaneous heating and cooling

5a) Removed minimum (electric) heating CFM from VAV control

5b) Selective testing of lowering max heating CFM on subset of VAV units to be closer

to 50% of max cooling CFM

1) Implemented to support efficiency during heating mode

1) Coordinated start times of AHUs and Boiler (now matched to 3am)

2a) Fixed stuck damper on AHU1

2b) Lower below 30% the minimum outside air damper position when building is

unoccupied (both heating and cooling modes)

2c) Match outside air supply on AHUs when the economizer is in the same position

(leaking damper on AHU1)

2d) Lowered min damper position to 30%

3) Raise supply air temperature setpoint from 68 to 75 degrees when building is in

warm up mode

4) Damper lockout setpoint lowered from 75 to 70 degrees

3) Recommended to support cooling efficiency

6) Reduce chiller primary flow to be limited to manufacturer maximum recommendation

Energy Use, Costs and CO2 Reductions

Implementing Accenture recommended changes would drive energy savings of

$119,202 (eq. 658,891 lbs CO2) per year, representing a total NPV of $458,588


Issue System Energy

(kWh)

Energy

(Therms)

$/

year NPV $

C02

(lbs/yr)

1) Boiler/AHU Startup Time Match N/A

2a) Stuck Damper Heating 2,409 2,409 2,409 32,395

Cooling 9,035 1,081 1,081 4,734 2b) Min Damper Unoccupied Setpoint Heating 2,891 2,891 16,966 38,874

Cooling 9,637 1,153 6,764 5,050 2c) Unmatched Damper Airflow N/A

2d) Min Damper Occupied Position

Setpoint Heating 2,409 2,409 14,139 32,395

Cooling 12,046 1,441 8,455 6,312

3) AHU SAT Setpoint Heating 2,409 2,409 14,139 32,395 4) Economizer Lockout Temp Setpoint Cooling 28,911 3,458 20,292 15,149 5ab) VAV Max Heating CFM Heating 4,954 4,954 29,074 66,616

Cooling 24,772 2,963 17,386 12,980 6) Chiller Efficiency Improvement Cooling 786,240 94,034 327,884 411,990

Total 870,641 15,073 $119,202 $458,588 658,891


Operational Guidelines – Exception Report

AFDD

Appendix

AFDD – Portal View

Operational Guidelines (OG):

Online Exception Report


Automated Fault Detection & Diagnostics (AFDD)

Online Portal View


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