Rowland Hall HVAC RetrofitBest Practice Award in HVAC Design and Retrofit 2011

Matt Gudorf

Campus Energy Manager

Nick Kimbell

Project Manager

Overview

Building Description

Project Scope of Work

Lab Air Control Valve Installation

New Method for Occupancy Control of Office and

Support Space

Successfully completing a UC Investor Owned

Utility partnership project

Economic and Environmental Analysis

Rowland Hall Rowland Hall is a 6-story, approximately 232,000 square-

foot, university laboratory building constructed in 1968. With a

seismic retrofit in 2007.

The building occupancy consists primarily of research

laboratories, teaching laboratories, classrooms, and offices

Fume Hood intensive with high hood density in multiple labs, there

are 168 fume hoods in the building.

100% Outside Air, Dual Duct

Second Largest Campus Energy Demand

Rowland Hall

HVAC Retrofit Project

Asbestos Abatement

Supply air duct cleaning

Constant Air Volume to Variable Air Volume

Pneumatic to Direct Digital Control

Static Pressure Control Damper Installation

Occupancy control of HVAC to offices at the zone level

Lab Air Control Valve Upgrade

Fume hood upgrades

Sash Position Sensors

Fume hood monitoring and alarm panel upgrade

Zone Presence Sensor installation

Test and Balance

Asbestos Abatement

Keys to Success

• Contractor provided with detailed

assessment prior to bid

• Contractor required to carry the

abatement subcontract to eliminate

the possibility of the University being

caught in the middle

• University EH&S personnel monitor

all abatement activities

Color Coded Assessment

When building load varies,

shouldn’t the HVAC system follow?

Constant Air Volume – Supply and Exhaust flow rate remains the same

independent of:

Fume hood sash position

Thermal demand

Occupancy

Variable Air Volume – Supply and Exhaust changes depending on:

Fume hood sash position

Thermal Demand

Occupancy

Constant Air Volume to

Variable Air VolumeConstant

Ve

nti

lati

on

Rate

(C

FM

)

VAV

270,000 CFM192,857 CFM

Savings of

77,500 CFM

Typical Lab Prior to Retrofit

Constant Volume

Phoenix Valves

Constant Volume Dual

Duct Mixing Boxes

Typical Lab Post Retrofit

Variable Volume

Phoenix Valves

Mixing Boxes for temperature

control and Phoenix Valves for

flow control

New Mixing

Boxes

Dual Duct to Phoenix Valve Connection

for Lab Supply Air and Proper Set UP

Duct static pressure must be

equal to prevent backflow Temperature control of

supply air

Control of flow

(CFM) of supply air

Zone Presence Sensors

Hood mounted occupancy controls

provide savings when sashes are

left open and unoccupied

CAV to VAV Lesson Learned

Static Pressure to lab air control valves is higher than what

should be supplied to a mixing box for an office.

Supply

duct

Hot and Cold Deck Supply to Floor

Lab S

upply

Ple

num

Offic

e S

upply

Ple

num

1.5” Static 1.5” Static

1.5” Static

Pressure Requirements for Lab Air

Control Valves and VAV Offices Would

Result in Excessive Duct Noise

Hot and Cold Deck Supply to Floor

Lab S

upply

Ple

num

Offic

e S

upply

Ple

num

1.5” Static .75” Static

1.5” Static Tracking

Exhaust Valve

Supply

Valve

Directional A

irflow

T

Position Feedback

Actuator C

omm

andsSingle Traccel™

Room

Controller

controls two valves

Exhaust duct Supply duct

Damper

Position signal

is sent to office

exhaust valve

to adjust office

exhaust rate

Static Pressure Control Added to

each floor

Pneumatic Control

to

Direct Digital Control

Direct Digital Controls

• Do not require frequent calibration.

• Can perform complex sequences.

• Can receive instructions from a master computer.

• Can transmit to a master computer information such as damper

position, room temperature, supply air quantity, and supply air temperature.

Additional Benefits of Direct Digital Controls in Rowland Hall

• Allow for occupancy based control of office spaces

• Provide static pressure reset data

Occupancy Based VAV for Offices

A New Approach

Goal: Save energy during unoccupied periods

Review of previous best practice

Rowland Hall’s approach

Occupied Mode

TEC

To exhaust

plenum

Unoccupied ModePrevious Best Practice

During periods of non occupancy

temperature dead band would be

increased to a wide range

If Unoccupied

Heat to 60

Cool to 80

TEC

Unoccupied ModePrevious Best Practice

Room temperature would move to

one extreme or the other and take

too long to normalize when

occupants returned to the space

80

60Time

TEC

When the room is unoccupied increase the dead band

for temperature control to heat to 60 cool to 80.

Unoccupied ModeNew method developed for Rowland Hall

During periods of non occupancy

Mixing Boxes are commanded to 3 modes

> 68 Mode 1

69-73 Mode 2

< 74 Mode 3

TEC

Unoccupied Mode 1

Thermostat Less than 68°F

Hot deck commanded to 10% open

Air flow is not measured and no

adjustments are made for duct pressure

changes.

Unoccupied Mode 2

Thermostat Between 68°-74° F

Hot deck commanded to 5% open

Air flow is not measured and no

adjustments are made for duct pressure

changes.

Cold deck commanded to 5% open

Unoccupied Mode 3

Thermostat Greater than 74°F

Cold deck commanded to 10% open

Air flow is not measured and no

adjustments are made for duct pressure

changes.

New Approach Provides Energy

Savings and Improves Occupant

Comfort

Energy savings from reduced air delivery during unoccupied periods

Offices maintain temperatures closer to occupied set points and return to set point faster upon entry.

Decrease wear on actuators prolongs life and reduces maintenance cost

80

60Time

SEP Partnership Steps

Implementation Cost

Energy and Environmental Savings

Payback

Project budget: $4,100,000

Annual energy savings (kWh, therms): 3,486,767 kWh with a 640 kW

demand reduction, reduced natural gas use by 98,000 therms

Annual cost savings: $442,550 ($0.105 kWh demand charges included, $0.78 Therm)

Annual cost to repay the bond: $306,564

CO2 emissions by 1,660 metric tons

Incentive payment from the IOU’s totaling $922,000

Contribution to Sustainability Goals

Emissions must be reduced to Year 2000 Levels By 2014 The Required Reduction as of

2010 is 25,953 Metric Tons of CO2e

Emission Reductions to be met through other projects 24,293 mtCO2e

Roland Hall Retrofit Emissions Reduction 1660 mtCO2e

Pre, 14187.52

Post, 7148.23

0

2000

4000

6000

8000

10000

12000

14000

16000

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7

Kilo

Watt

Ho

urs

kWh for Supply and Exhaust Fans

0.00

20.00

40.00

60.00

80.00

100.00

Supply Fan 1

Supply Fan 2

Supply Fan 3

Supply Fan 4

Exhaust Fan 1

Exhaust Fan 2

Exhaust Fan 3

Average kW

Post Retrofit Pre Retorfit

5,426,676

2,620,956

-

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

Pre Retrofit kWh for 1 Year Post Retrofit kWh for 1 Year

Rowland Hall Fan Energy Yearly Savings

Pre Retrofit kWh for 1 Year

Post Retrofit kWh for 1 Year

This concludes The American Institute of Architects

Continuing Education Systems Program