REQUEST FOR PROPOSALS (RFP) For the City of West Des ...

REQUEST FOR PROPOSALS (RFP)

For the City of West Des Moines

HVAC STUDY FOR CITY OF WEST DES MOINES PUBLIC WORKS BUILDING

AND FIRE STATION 17

1. INTRODUCTION

The City of West Des Moines is requesting proposals from firms interested in providing Professional Services for a

study of the existing Heating, Cooling, Ventilation and Air Conditioning (HVAC) systems of the West Des Moines

Public Works building located at 560 South 16th

Street and Fire Station 17 located at 1401 Railroad Avenue, both in

West Des Moines, Iowa. Firms with relevant experience and qualifications are encouraged to submit.

It is the intent of this process to select a firm to be awarded a contract for Professional Engineering Services for the

following: HVAC Study for the City of West Des Moines Public Works Building and Fire Station 17 as specified in

this Request.

2. PROCESS

A. DISTRIBUTION OF REQUEST FOR PROPOSALS (RFP) – This RFP document will be made available

only to individuals or firms that are licensed in the State of Iowa. Notice will be published in the Des

Moines Register. The RFP and any supporting documents will be made available via electronic distribution

as requested by any qualified firm or individual and be posted on the City of West Des Moines web site:

www.wdm.iowa.gov.

B. PROPOSAL PERIOD – The Proposal Period shall remain open from April 18, 2012, through May 2, 2012

at 2:00 pm.

C. QUESTION AND ANSWERS - During the proposal period, firms will be allowed to submit to the City

written questions and requests for additional information via Linda Schemmel, AIA, at

[email protected]. All questions and requests received by 3:00 p.m., each day will be

answered via e-mail to all interested design teams by the following morning by 10:00 a.m. unless the nature

of the question or request requires further time or research to issue a proper response. The last date for

submittal of written questions is April 30, 2012. Please forward the contact information, including e-mail

address, for the project staff person that will be receiving any responses for this project by 10:00 a.m., April

20, 2012.

D. RECEIVE PROPOSALS – The submittal shall be addressed to the City Clerk’s office at 4200 Mills Civic

Parkway, Suite 1A, West Des Moines, Iowa, 50265, and will be accepted until 2:00 p.m., on Wednesday

May 2, 2012. Submittals and materials received after the time specified above will not be considered and

will be returned to the sender. Please provide three (3) bound hard copies of the proposal and one (1) PDF

copy.

E. REVIEW OF PROPOSALS BY SELECTION COMMITTEE – Proposals submitted will be reviewed by

the Committee the week of May 7, 2012. Materials reviewed shall be limited to only those submitted by

the proposal deadline.

F. PROPOSAL ACCEPTANCE, REJECTION - The Selection Committee reserves the right to:

Waive any informality or irregularity in any proposal received;

Reject a proposal if it is not in full and complete compliance with the requirements and

formats specified herein;

Reject a proposal which is in any way incomplete or irregular;

Reject all proposals if the proposals do not meet the overall standards established by this Request for

Proposals, are otherwise inappropriate, or if it is in the best interest of the City to reject all proposals.

If the City so rejects all proposals it may thereupon either cancel this solicitation or re-solicit for

proposals.

mailto:[email protected]

3. EVALUATION OF PROPOSALS

The following criteria shall be included in the proposal and will be used in evaluating and rating submitted

proposals. The right is reserved hereunder to modify these criteria and to add or delete criteria.

A. PROJECT TEAM

Provide up to four project examples demonstrating:

1. Comparable undertakings.

2. Prior experience of design team members working in a collaborative relationship with clients.

3. Demonstrated ability to lead the City of West Des Moines in the implementation of study

recommendations if so desired by the Mayor and City Council of the City of West Des Moines.

B. SERVICES

1. Include a summary of the Scope of Services with the proposal.

2. Include a proposed schedule and capacity of team members staffing.

C. FEES

1. Services shall be provided on an hourly basis. Provide in the proposal a not-to-exceed sum including

reimbursable expenses.

2. Fees should be based on services provided for the following study scope (see Exhibit A for detailed

scope of services information):

a. Evaluation of existing HVAC systems

b. Calculation of building’s thermal load

c. Recommendations of possible energy savings measures for the systems

d. Action plan for retrofit/replacement of HVAC systems

e. Preliminary cost opinion

4. DELIVERABLES

By July 15, 2012, the selected team will deliver to the City a written report (s) detailing all findings of the HVAC

study along with recommendations, action plan and preliminary cost estimates for system improvements. The report

must include, at a minimum, responses to the scope as detailed above. The selected firm will provide three (3)

bound hard copies of the report and one (1) PDF copy. The City of West Des Moines will own the results of the

study and may use said results as determined to be in the best interests of the City of West Des Moines.

5. TENATIVE PROJECT SCHEDULE

Included below for reference is the tentative project schedule. Schedule is subject to change.

April 18, 2012 Request for Proposals distributed

May 2, 2012 Proposals due to City Clerk by 2:00 p.m.

Week of May 5, 2012 Committee reviews proposals and recommends firm

May 15, 2012 Committee recommendation review by Council Subcommittee

May 29, 2012 City Council awards contract(s)

May 30, 2012 Analysis begins

July 15, 2012 HVAC study report due

6. SUPPORTING DOCUMENTS

The following information will be is attached herein as an Exhibit:

Exhibit A – Scope of Services Description

Exhibit B – Site Information Form – West Des Moines Public Works Building

Exhibit C - Energy Assessment Report – West Des Moines Public Works Building

Exhibit D – Site Information Form – West Des Moines Fire Station 17

Exhibit E - Energy Assessment Report – West Des Moines Fire Station 17

Exhibit F – Base Consultant Services Contract, City of West Des Moines.

Exhibit A – Scope of Services

Public Works Building

The Public Works building provides Operational and Engineering related services for the City of West Des Moines. The facility has approximately 56,940 square feet of gross floor area and was built in 1959. There were two modular

offices added in 1990 for the engineering department. Office areas occupied a total of 23 percent of the facility gross

floor area and the rest of the building is served as a repair shop and garage. The building is divided into 4 different

HVAC service areas with different system types and ages (See Exhibits B and C for detailed information).

A HVAC study will provide the owner with a plan to address replacement or retrofit of the existing building systems

along with identification of energy savings measures. The following services are expected:

Evaluation of existing HVAC systems

Documentation of existing systems existing conditions and performance including but not limited to:

o Equipment sizing

o Equipment age

o Operational efficiency

o Verify correct installation and operation to meet code requirements

o Verify appropriate ventilation supply

o Verify existing static air pressure and temperature rise/fall

o Duct size and routing

o Duct air leakage

o Duct insulation

o System balance

Calculation of building’s thermal load

Calculations based on existing building envelope including load requirement for individual rooms to allow

for proper system sizing.

Recommendations of possible energy savings measures for the systems

Energy savings measure shall include estimated project cost (including professional fees) and estimated

payback based on energy and maintenance cost savings. Recommendations could include:

o Replacement HVAC system type and efficacy

o Retrofit of duct or delivery system

o Upgrade of system controls

o Upgrade of ventilation equipment or controls

o Upgrade of system motors or controls

Action plan for retrofit/replacement of HVAC systems

After owner reviews and provides direction on possible energy savings measures, provide recommendation

of systems replacement/upgrades. Organize recommendations into logical projects and recommend time

frame to implement projects. Recommendations will need to take into account a change in occupancy and

function as it is anticipated that the Public Works functions will move and a different City department may

occupy the building.

Preliminary cost opinion

Prepare preliminary cost opinions for identified projects (including professional time) to establish budget

and pursue funding sources.

Fire Station 17

Fire Station 17 provides Fire and EMS department related services for the City of West Des Moines. The facility has

approximately 18,000 square feet of gross floor area and was built in 1991. Office and dorm areas occupy a total of

78 percent of the facility gross floor area and the rest of the building is serving as a garage space for the trucks and

equipment. The building is divided into 3 different HVAC service areas with different system types. All the

equipment is original to the building (See Exhibits D and E for detailed information).

A HVAC study will provide the owner with a plan to address replacement or retrofit of the existing building systems

along with identification of energy savings measures. The following services are expected:

Evaluation of existing HVAC systems

Documentation of existing systems existing conditions and performance including but not limited to:

o Equipment sizing

o Equipment age

o Operational efficiency

o Verify correct installation and operation to meet code requirements

o Verify appropriate ventilation supply

o Verify existing static air pressure and temperature rise/fall

o Duct size and routing

o Duct air leakage

o Duct insulation

o System balance

Calculation of building’s thermal load

Calculations based on existing building envelope including load requirement for individual rooms to allow

for proper system sizing.

Recommendations of possible energy savings measures for the systems

Energy savings measure shall include estimated project cost (including professional fees) and estimated

payback based on energy and maintenance cost savings. Recommendations could include:

o Replacement HVAC system type and efficacy

o Retrofit of duct or delivery system

o Upgrade of system controls

o Upgrade of ventilation equipment or controls

o Upgrade of system motors or controls

Action plan for retrofit/replacement of HVAC systems

After owner reviews and provides direction on possible energy savings measures, provide recommendation

of systems replacement/upgrades. Organize recommendations into logical projects and recommend time

frame to implement projects.

Preliminary cost opinion

Prepare preliminary cost opinions for identified projects (including professional time) to establish budget

and pursue funding sources.

Exhibit B

*EPA Energy Star Buildings benchmarking data 1

EfficiencyPartners® - SITE INFORMATION FORM

Name: Linda Schemmel Title: Planner - City of West Des Moines

E-mail Address: [email protected] Business/Cell Phone: 515-222-3620

Building Name & Address: Public Works Maintenance Facility – 560 South 16th Street, WDM, IA

Building Information

Characteristic Description

1. Year of construction 1959 (Modular offices added in 1990)

2. Building use (e.g. office, school, hospital) Office/Shop

3. Number of occupants 65 (2/3’s are intermittent throughout the day)

4. Number of personal computers in operation (approx.)* 47

5. Annual occupancy rate of primary space by year*

Year Rate (% full)

2006 100

2007 100

2008 100

6. Building occupied for 11 or more of last 12 months?* Yes

Square Footage %Heated/

Cooled

7. Gross area (gross square footage)* 56,940 100

23

8. Percent of gross area designated as prime office space* 23 (13,240) 100

100

9. Percent of gross area designated as warehouse space Shop - 77 (43,700) 100

0

10. Percent of gross area designated as manufacturing space

11. Weekly hours of operation by major space type*

Space Type Hours

Office 50

Shop 70

12. Brief renovation history (Attach separate sheet as required) HVAC upgrade 1997-98, site improvements ‘92-‘94

13. Brief description of building/energy improvements planned

(Attach separate sheet as required).

14. Type of cooling system (e.g. Chiller, packaged A/C) FURNACES/CONDENSERS

CO-RAY VAC GAS FORCED AIR

15. HVAC distribution system (e.g. constant volume, variable

volume, dual duct, multi-zone)

16. HVAC control system type (e.g. pneumatic, DDC)

17. Building meter and account number Gas meter: ? account: 37270-47028

Elec. meter: L80592662 account: 37270-47011

18. Permission to access 2 years of meter data Yes

Email or Fax Completed Form to: 2

[email protected]

Fax: 608-829-2723

Please complete the following table listing the facilities major HVAC and lighting system components.

Add more rows as necessary or attach a separate equipment list.

Area 1

Equipment Type Size Age

Cooling Equipment

CARRIER CONDENSER (SOUTH

OFFICES)

M-

38EN0605205M

S-5286F81471

CARRIER CONDENSER (NORTH

O/LOCKER ROOM)

M-56AP042-A

S-2094E14858

CARRIER CONDENSER (MAIN

OFFICES) 5-0487E30306 M-38EN048520

Heating Equipment

CARRIER (#1) GAS FURNACE

(SOUTH OFFICES) 114,000 BTU

M-585BO95DC

S-1385C23917


(NORTH/LOCKER ROOM) 95,000 BTU

M-25653080-06

S-175695853


(MAIN AREA) 114,000 BTU M-585BO95C

Heat Rejection Equipment

Air handling Equipment

Lighting Systems

T-12 2X4’=11

T-8 4X4’=105

Domestic Hot Water

Motors (Over 5 HP)


[email protected]

Fax: 608-829-2723

Area 2


Cooling Equipment

LENNOX CONDENSER (ENG.) M-H524-413-1Q

SN-5192F03771

CARRIER AIR HANDLER CONDENSER

M-38ARS012---

511—

SN-0404G30005

YORK CONDENSER (BREAK ROOM)

3 TON

M-HIRA036525B

S-WFKM034638

Heating Equipment

AMANA GAS FURNACE (ENG.)

92,000BTU

M-GCIC090CX50

SN-9609127777

GOODMAN GAS FURNACE

(HALL/OFFICES)

100,000BTU

M-GMP-100-3

REV B

SN-0010618627

RADCO ELECTRIC FURNACE

(BREAKROOM)

M-FB4ANF036

S-1193A00657


(4) EXHAUST FANS

(RESTROOMS) UNDER 5 HP


CARRIER AIR HANDLER/COOLING

M-40RR012430

3HP

S/N M496230

Lighting Systems

T-12 2X4’=11

T-8 4X4’=105

Domestic Hot Water

RHEEM WATER HEATER 50 GALLON

40,000BTU

M-41V50

S-

RHNG1297A32

42

Motors (Over 5 HP)


[email protected]

Fax: 608-829-2723

Area 3


Cooling Equipment

BARD (ET – EU) A/C M-WA372-A15

S/N- 225A072296513-02 2007

BARD (4 UNITS) A/C ALL MODEL #WA361-A15 1996

Heating Equipment

BARD (3 UNITS) ELECTRIC HEAT ALL MODEL

#EW4A03-A15 1996



Lighting Systems

FLOR. TUBES

W- T-12 23-2X4’

W- T-12 5-4X4’

E- T-12 27-2X4’

4-4X4’

Domestic Hot Water

Motors (Over 5 HP)


[email protected]

Fax: 608-829-2723

Area 4 (Shop)


Cooling Equipment

Heating Equipment

REZNOR TUBE HEATER 125,000 BTU 1995

REZNOR TUBE HEATER 125,000 BTU 1996

CO RAY VAC (32) RADIANT HEAT M#CRV-A4 40,000 BTU S/N 145733

WEATHER KING FURNACE GAS (OK ROOM) 50,000BTU 2006

REZNOR HANGING HEATER (PAINT

ROOM)

30,000BTU

M#UDBP30

S/N

REJ79Y2NO51

6X


INDUSTRIAL PRODUCTS EXHAUST FAN MOD#8122 A/10 1962

CENTRI MASTER EXHAUST FAN HIGH ROOF 208V 3HP M-PV365

S#NYD19701

CENTRI MASTER EXHAUST FAN HIGH ROOF 208V 1 1/2HP M-PV300

S-UXC046105

CENTRI MASTER EXHAUST FAN 208V 1 1/2HP PV-240

UXC046101

CENTRI MASTER EXHAUST FAN 208V 1 1/2HP PV-240

09CV673-1


HASTINGS MAKE UP AIR UNIT/HEAT

GAS 5000025CPM 40HP SN53665

BTU 4696000 MOD# SBD-

227-50125-4696

WALL EXHAUST FANS (4) 208 VOLT

1HP ?

Lighting Systems

(58) 120 VOLT 400WATT

MH

120 VOLT 48” T5-HO

36@/6EA

120 VOLT T-12-96” 18@2/EA

120 VOLT T-12-48” 14@2/EA

T-8-48” 36@4/EA

T5-HO 48”=24/2EA


[email protected]

Fax: 608-829-2723

Domestic Hot Water

RHEEM WATER HEATER 50 GALLON

40,000 BTU

M-41V50

S-

RHNG1297A32

42

Motors (Over 5 HP)

If a manufacturer:

1. Attach list of major manufacturing equipment (e.g. compressed air system, motors, furnaces,

etc.) with operating hours, or

2. Attach Iowa Energy Sales Tax Exemption data listing equipment sizes and hours of operation

November 30, 2009

Linda Schemmel

City of West Des Moines

4200 Mills Civic Pkwy, Suite 2D

West Des Moines, IA 50265

Ms. Linda Schemmel,

On behalf of MidAmerican Energy Company’s Nonresidential Energy Analysis program, Nexant is

pleased to provide you the attached Facility Walk-through Energy Assessment report for the City of West

Des Moines’s Public Works. The report presents the findings and recommendations resulting from the

Wednesday, September 30, 2009, walk-through energy assessment and subsequent analysis completed for

the facility.

Please carefully review and evaluate the technical and financial aspects of the recommendations presented

in the report. MidAmerican and Nexant encourage you to act on those that meet the fiscal and operational

requirements of your facility. To encourage implementation of projects MidAmerican’s standard

equipment rebates are available.

A Nexant engineer will contact you within the next ten days to discuss the report and your next steps

moving forward.

Sincerely,

Brian Ng

Nexant, Inc.

1232 Fourier Drive, Suite 125

Madison, WI 53717

phone (608) 824-1220

fax (608) 829-2723

email [email protected]

CC: Richard C. Walker, MidAmerican Energy Efficiency Product Manager

LSchemmel

Typewritten Text

Exhibit C

LSchemmel

Typewritten Text

LSchemmel

Typewritten Text

LSchemmel

Typewritten Text

LSchemmel

Typewritten Text

Facility Walk-through Energy Assessment:

City of West Des Moines

Public Works West Des Moines, IA

Prepared by Nexant, Inc. on behalf of MidAmerican Energy Company,

Nonresidential Energy Analysis

November 30, 2009

MidAmerican Energy City of West Des Moines – Public Works i

Nonresidential Energy Analysis Facility Walk-through Energy Assessment

Table of Contents

SECTION 1 EXECUTIVE SUMMARY ............................................................................................................... 1

SECTION 2 PROJECT CONTACTS .................................................................................................................... 4

SECTION 3 SITE INFORMATION ..................................................................................................................... 6

3.1 General Facility Information ....................................................................................................................... 6 3.2 Energy Systems ........................................................................................................................................... 6

3.2.1 Compressed Air System ......................................................................................................................... 6 3.2.2 Facility Heating, Cooling, and Ventilation ............................................................................................ 6 3.2.3 Domestic Hot Water Heating ................................................................................................................. 6 3.2.4 Lighting .................................................................................................................................................. 6

3.3 Energy Use and Costs .................................................................................................................................. 7 3.4 Benchmarking Results ................................................................................................................................. 9

SECTION 4 ENERGY PROJECT OPPORTUNITIES ....................................................................................... 10

4.1 Detailed Study Project Opportunities ........................................................................................................ 10 4.2 Low-Cost Project Opportunities ................................................................................................................ 10

4.2.1 Install Vending Machine Controls ....................................................................................................... 10 4.2.2 Reduce Compressed Air System Pressure ............................................................................................ 11 4.2.3 Install LED Exit Signs.......................................................................................................................... 11 4.2.4 Optimize Air-side Dry-bulb Economizer Controls ............................................................................... 11 4.2.5 Utilize Temperature Setback ................................................................................................................ 12

4.3 Capital Investment Project Opportunities .................................................................................................. 12 4.3.1 Replace HID Lighting with High-Bay Fluorescent .............................................................................. 12 4.3.2 Upgrade T12 Fluorescent to T8 Fluorescent Lighting ........................................................................ 13 4.3.3 Install Lighting Occupancy Sensors .................................................................................................... 13 4.3.4 Replace Existing Equipment with High Efficiency ............................................................................... 13

4.4 Other Opportunities ................................................................................................................................... 15 4.4.1 Reduce Hot Water Temperature Set-Point ........................................................................................... 15

SECTION 5 CONCLUSION ............................................................................................................................... 16

SECTION 6 APPENDIX ...................................................................................................................................... A

MidAmerican Energy City of West Des Moines – Public Works Page 1


Section 1 Executive Summary

Nexant Inc., on behalf of MidAmerican Energy Company (MidAmerican), has completed a facility walk-

through energy assessment for the City of West Des Moines’s Public Works building in West Des

Moines, Iowa. The Public Works building provides Operational and Engineering related services, which

includes street and sewer maintenance, and the design and construction for all public improvements in the

City of West Des Moines. The walk-through was conducted on Wednesday, September 30, 2009.

Present for the walk-through were Brian Ng and Duane Paul of Nexant and Linda Schemmel of City of

West Des Moines. The objective of this walk-through was to identify opportunities to reduce energy

consumption at the facility while maintaining or improving the facility’s operations.

Tasks undertaken for this assessment were as follows:

Historical trends and benchmarking: Utility bills were evaluated for consumption levels and

trends over the past 24 months. The facility was benchmarked using the 2003 Commercial

Buildings Energy Consumption Survey (CBECS) conducted by the U.S. Department of Energy’s

Energy Information Administration.

Site assessment: A walk-through assessment of the facility was conducted, which included an

overview of the building’s major production, heating, cooling, ventilation, and lighting systems.

Analysis: Project opportunities were identified, and energy savings were approximated, based on

site-specific energy use and energy costs and industry standard engineering estimation methods.

Recommendations: Recommendations for energy efficiency, energy conservation, load

management, and/or energy recovery projects are provided as appropriate.

Benchmarking results from the CBECS data showed that the building uses more energy than similar

facilities throughout the United States.

The energy project opportunities identified at the Public Works building as a result of this facility walk-

through energy assessment are summarized in Table 1.



Table 1: Energy Project Opportunities Summary - Public Works

ID Type* Name

Annual

Energy Cost

Savings

Installed CostEstimated

Incentive

Simple

Payback

(years)

1 LC

Install Vending

Machine Controls $96 $440 $100 3.5

2 LC

Reduce Compressed

Air System Pressure $452 $100 $0 0.2

3 LC Install LED Exit Signs $33 $750 $25 22.0

4 LC

Optimize Air-side Dry-

bulb Economizer

Controls $131 $700 $393 2.3

5 LC

Utilize Temperature

Setback $3,779 $500 $0 0.1

6 CI

Replace HID Lighting

w ith High-Bay

Fluorescent $4,365 $15,950 $4,872 2.5

7 CI

Upgrade T12

Fluorescent to T8

Fluorescent Lighting $621 $7,820 $1,296 10.5

8 CI

Install Lighting

Occupancy Sensors $344 $2,485 $180 6.7

9 CI

Replace Existing

Equipment w ith High

Efficiency $1,033 $2,040 $600 1.4

Total $10,854 $30,785 $7,466 2.1

*DS - Detailed Study, LC - Low -Cost Opportunity, CI - Capital Investment Opportunity

Measure DescriptionStandard MidAmerican

ProgramsEstimated Costs

As detailed in Table 1, the identified project opportunities have the potential to reduce the total energy

expense at the facility by $10,854 each year, which would reduce the facility’s annual energy expenditure

by about 15.7 percent based on the past 12 months of utility data and an assumed gas cost of $0.80 per

therm. The estimated cost to install these projects is $30,785. Also as shown in the table, there are cash

incentives available from MidAmerican to help overcome the initial cost of installing the projects. The

standard incentives presented in Table 1 are those available through either MidAmerican’s prescriptive

Nonresidential Equipment rebate programs or MidAmerican’s Custom Systems program (for measures

not covered by prescriptive equipment rebates).

As shown above, the incentive available from MidAmerican would amount to $7,466 if all measures are

implemented as suggested. After considering the cash incentive, the total investment required by the City

of West Des Moines would be $23,319. Due to the annual cost savings, the investments would have a

combined net simple payback of 2.1 years, which is equivalent to a simple return on investment of 47

percent.

NOTE: All recommendations included in this report are based on observations made during the walk-

through assessment and information provided by facility personnel. The savings estimates given in this

report are first-order estimates and are not intended to be used to justify capital investment without further

consideration; rather, they are provided as a guide for selecting measures and projects for further review.

Incentive values included in this report are estimated based on the best information available at the time

of the walk-through and are subject to change based on the final scope of the proposed project(s), which

may include changes in equipment types, quantities, specifications, usage factors, and/or costs. In

addition, all projects must meet State eligibility guidelines before they can be approved for MidAmerican



incentives; until the final scopes and costs of the proposed projects are established, the custom projects

recommended in this report can not be assumed to be automatically pre-approved for any MidAmerican

incentive. Custom projects installed by the customer without pre-approval may not be eligible for rebate

incentives.



Section 2 Project Contacts

Table 2 identifies the project team members associated with the facility walk-through energy assessment

and their contact information.

Table 2: Project Contacts

Name Role Organization Contact Information

Linda Schemmel Planner City of West Des Moines

4200 Mills Civic Pkwy, Suite 2D

West Des Moines, IA 50265

515-222-3620

[email protected]

Richard C. Walker Energy Efficiency Product Manager

MidAmerican Energy 106 E. Second Street

Davenport, IA 52801

563-333-8841 phone 563-333-8252 fax

[email protected]

Brian Ng

Brian Albert

Robin Flick

EfficiencyPartners Program Contractors

Nexant, Inc. 1232 Fourier Drive, Suite 125

Madison, WI 53717

608-824-1220 phone 608-829-2723 fax

[email protected]

[email protected]



Abbreviations °C Degrees Celsius

°F Degrees Fahrenheit

A Amps

AFUE Annual Fuel Utilization Efficiency

AHU Air Handling Unit

ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers

ASME American Society of Mechanical Engineers

Btu British thermal units

CBECS Commercial Buildings Energy Consumption Survey

CFM Cubic Feet per Minute

CHW Chilled Water

COP Coefficient of Performance

DHW Domestic Hot Water

DOE Department of Energy

ECM Energy Conservation Measure

EER Energy Efficiency Ratio

EIA Energy Information Administration

EPA U.S. Environmental Protection Agency

ft foot

ft2 square foot

gpm gallons per minute

HID High-Intensity Discharge

hp horsepower

hr hour

HVAC Heating, Ventilation and Air-Conditioning

HW Hot Water

in Hg inches of mercury (pressure)

in WC inches of Water Column (pressure)

in inch

IR Infrared

kBtu 1 thousand Btu

Kvar Kilovolt-amp reactive (power)

kW kilowatt

kWh kilowatt-hour

MBH 1 thousand Btu per Hour

min minutes

MMBtu 1 million British thermal units

MW Megawatt

NEMA National Electrical Manufacturers Association

O&M Operations and Maintenance

pph pounds per hour steam

psi pounds per square inch (pressure)

psig pounds per square inch gage (gage pressure)

RTU Rooftop Unit

SCFM Standard Cubic Feet per Minute

SEER Seasonal Energy Efficiency Ratio

ton 12,000 Btu/hr of heat transfer

V Volts

VAC Volts Alternating Current

VDC Volts Direct Current

VFD Variable Frequency Drive

VSD Variable Speed Drive

W Watt



Section 3 Site Information

3.1 General Facility Information

The Public Works building is located at 560 S. 16th Street in West Des Moines, Iowa. The facility has

approximately 56,940 square feet of gross floor area and was built in 1959. There were two modular

offices added in 1990 for the engineering department. Office areas occupied a total of 23 percent of the

facility gross floor area and the rest of the building is served as a repair shop and garage. There are plans

to move out of the existing Public Works building in the next five to six years.

3.2 Energy Systems

3.2.1 Compressed Air System

An Ingersoll-Rand 10 hp compressor is installed in the facility. The compressor operates year around to

provide compressed air to the sprinkler system and the shop’s air powered equipment. According to

facility personnel, the outlet pressure of the compressor is set at 160 psi.

3.2.2 Facility Heating, Cooling, and Ventilation

Area 1 of the building is cooled by three Carrier roof top units, which have been installed in the building

for over 10 years. Space heating is provided by another three Carrier gas furnaces which are

approximately the same age as the cooling units.

Area 2 is cooled with three units (Carrier, Lennox and York), and heated by a Radco electric furnace and

two gas furnaces (Amana and Goodman). A constant volume air handling unit is also used in this area to

provide outside air during the cooling season. This unit has economizer with an outside air changeover

point at 60 degrees, which disables economizer operation and enables compressor operation when outdoor

air exceeds the changeover point; the minimum and maximum outside air is varying between 0 to 50

percent, respectively.

Area 3 of the building is heated and cooled with three Bard wall mounted unitsand five Bard units,

respectively. The Bard wall mounted units were installed in 1996.

Area 4 (garage and the shop area) is heated with two gas furnaces, two Reznor tube heaters, and a

CORAYVAC infrared heating system. There are five exhaust fans installed in this area that operate when

vehicles run in this area. No cooling is provided in Area 4.

3.2.3 Domestic Hot Water Heating

Gas fired domestic hot water heaters were installed in Area 2 and 4, which provide domestic hot water to

the whole facility. Each domestic heater has a 50 gallon tank and 40,000 BTU input with approximately

80% efficiency.

3.2.4 Lighting

Area 1 and 2 of the building utilize both 32-Watt T8 linear fluorescent fixtures with electronic ballast and

34-Watt T12 linear fluorescent fixtures with magnetic ballast. No occupancy sensors were installed in

these areas except the restrooms.

Area 3 uses T12 linear fluorescent fixtures with magnetic ballast. No lighting controls are installed in this

area.

Area 4 has a combination of 400 W metal halide, T12, T8, and T5 fluorescent fixtures. No lighting

controls are used in this area.

According to the maintenance staff, light fixtures are turned off during unoccupied hours in all fours

areas; however, the hours of operation for the light fixtures in area 4 vary based upon the season. During



winter, there are more activities and traffics in Area 4, where the light fixtures can be stayed on the whole

day.

3.3 Energy Use and Costs

The City of West Des Moines purchases electricity from MidAmerican under Rate ADS. City of West

Des Moines - Public Works is a MidAmerican transport gas customer and transports gas under Rate

MTM for the Public Works building.

Figure 1 and Figure 2 illustrate the monthly electricity demand and consumption profiles, respectively, for

the Public Works building over the last 24 months. Electricity use at this facility is primarily driven by

occupancy. The facility has an average peak energy consumption of 65,940 kWh per month (average

from January of 2008 and January of 2009) during periods of high occupancy and an average minimum

consumption of 30,030 kWh per month (average from November of 2007 and November of 2008) during

periods of low occupancy. Based on the trends shown in the figures, approximately 54 percent of annual

electricity use at the facility is driven by occupancy. The remaining 46 percent of annual electricity use

serves loads independent of occupancy, such as lighting.

Figure 1: Electricity Demand Profile – Public Works

Figure 2: Electricity Use Profile – Public Works

Figure 3 illustrates the monthly natural gas consumption profile for the Public Works building over the

last 24 months. Natural gas consumption over the past two years has averaged 93 therms per month in

0

20

40

60

80

100

120

140

160

180

200

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Dem

an

d(k

W)

Month

2007

2008

2009

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000


Co

nsu

mp

tio

n(k

Wh)

Month

2007

2008

2009



the summer months and 7,734 therms per month in the winter months. Based on these trends, the facility

has a base natural gas consumption of approximately 93 therms per month, which serves domestic hot

water heating; consumption for space heating, based on the seasonal variation observed, accounts for

about 97 percent of all natural gas use.

Figure 3: Natural Gas Consumption Profile – Public Works

Figure 4 illustrates the total monthly energy expenses for the facility in 2008. For the twelve month

period ending in December 2008, the Public Works building total electricity consumption was 490,920

kWh for a total electricity expenditure of $32,092, which is equivalent to an average cost of $0.0654 per

kWh. Over the same time period, the facility’s total natural gas consumption was 47,118 therms. City of

West Des Moines - Public Works is a transport gas customer and the actual cost per therm was not

provided. If a total gas cost of $0.80 per therm is assumed, then the annual gas expenditure would be

approximately $37,694.

$0

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

$14,000

Co

st

($)

Month

Gas - 2008

Electricity - 2008

Figure 4: Monthly Energy Costs – Public Works

Figure 5 shows the typical breakdown of energy consumption by end-use for service buildings, as

published in the 2003 Commercial Buildings Energy Consumption Survey (CBECS) conducted by the

U.S. Department of Energy’s Energy Information Administration. As shown in Figure 5, space heating is

the single largest end-use of energy in typical service buildings, accounting for approximately 47 percent

of all energy consumption at the facility. Another major energy consumer is lighting.

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000


Co

nsu

mp

tio

n (

therm

s)

Month

2007

2008

2009



47%

5%8%1%

20%

0%

3%0%

1%15%

Service

Space Heating

Cooling

Ventilation

Water Heating

Lighting

Cooking

Refrigeration

Office Equipment

Computers

Other

Figure 5: Typical Breakdown of Energy Consumption – Service Building

3.4 Benchmarking Results

Portfolio Manager is an online benchmarking tool provided by the U.S. Environmental Protection

Agency. Portfolio Manager provides a powerful environment for tracking energy performance and

benchmarking buildings’ energy usage. A facility's historical energy consumption is normalized for

several significant factors such as the building’s size, function, geographical location, and other

parameters. The facility is then given an Energy Performance Rating, which ranks the facility’s energy

performance in comparison to that of similar facilities across the United States on a scale of 1(worst

performance) to 100 (best performance). For example, an Energy Performance Rating of 50 indicates that

about half of similar facilities in the United States are less energy intensive than the rated facility, and half

are more energy intensive. A facility that scores 75 or higher is eligible to receive the ENERGY STAR

label.

Nexant could not enter the Public Works building into Portfolio Manager because service buildings are

not among the building types currently supported by the program. However, Portfolio Manager may add

this and other building types in the future. Nexant is available to advise and assist with Portfolio Manager

benchmarking if the tool expands its offerings to include service buildings.

As a point of comparison, according to the 2003 Commercial Buildings Energy Consumption Survey

(CBECS) conducted by the U.S. Department of Energy’s Energy Information Administration, the national

average energy intensities by fuel type for service buildings were 11.0 kWh/square foot (37.5 kBtu/square

foot) for electricity and 54.1 kBtu/square foot for natural gas, for a total average intensity of 91.6

kBtu/square foot. The Public Works building energy intensity is 107.8 kBtu/square foot, which is greater

than the national average for service buildings.



Section 4 Energy Project Opportunities

The following section details the energy project opportunities identified at the Public Works building as a

result of the facility walk-through. The recommended energy project opportunities are organized into the

following categories:

Detailed Study Project Opportunities

Low-Cost Project Opportunities

Capital Investment Project Opportunities

Other Opportunities

4.1 Detailed Study Project Opportunities

Detailed studies are defined as engineering studies that include an in-depth investigation of one or several

potential energy efficiency or energy conservation projects. The study may focus on identifying energy

improvement projects beyond the scope of the initial walk-through assessment, or a study may be used to

further define the scope, investigate the feasibility, and/or accurately quantify the energy and cost impacts

of a previously recommended energy conservation measure. No opportunities for detailed studies were

identified during the facility walk-through.

4.2 Low-Cost Project Opportunities

Low-cost measures are defined as energy conservation, energy efficiency, or time-of-use management

projects that have either no associated cost (not including internal labor) or have a capital cost of less than

$1,000. No-cost measures reduce energy usage and costs with no capital investment, except for the time

and effort of the on-site maintenance personnel. No-cost measures are not eligible for MidAmerican

rebates, but the measures should still be pursued for their long-term energy and cost savings potential.

Low-cost measures significantly reduce energy consumption and costs while requiring relatively little

capital investment.

4.2.1 Install Vending Machine Controls

Vending machine controls offer sensor-activated power control of vending machine lighting and

compressor energy, which significantly reduces energy consumption without compromising the product.

The vending machine control utilizes a passive infrared sensor to detect people in the area of the vending

machine. The controller will power down the vending machine when the area surrounding it is

unoccupied and it will automatically power up the unit when the area is occupied. For refrigerated

beverages, the controller will also cycle the compressor on to maintain cold beverage temperatures. It

should be noted that vending machine controls cannot be used on vending machines with perishable food

products, such as machines containing sandwiches.

During the walk-through, two beverage machines and one snack machine were identified. Estimated

annual energy savings for the Install Vending Machine Controls measure are 2,100 kWh, for total

estimated cost savings of $96 per year. First-order estimate of cost to install this measure is $440, for an

estimated simple payback of 4.6 years prior to any incentives available from MidAmerican.

This measure is eligible for a of $100 rebate from MidAmerican based upon the reported opportunities. A

completed Project Installation Notification (PIN) form with a copy of the paid invoice for the purchase

and installation of the controllers is required to receive the rebate. Enclosed is a PIN form for that

purpose if the City of West Des Moines chooses to pursue this project. Please complete, sign and return

the form with a copy of the paid invoice to Nexant for processing.



4.2.2 Reduce Compressed Air System Pressure

The compressed air system operates year around at 160 psig. Reducing the pressure of the compressed air

reduces compressor energy consumption. As a general rule of thumb, each 1 psi decrease in discharge

pressure decreases system operating cost by 0.5 percent. Assume the maximum air pressure requirement

of any tools in the facility is 120 psi. It is recommended that the pressure be dropped to at least 130 psig

to realize a 15 percent savings in compressed air system energy consumption. The recommended

pressure of 130 psi should provide sufficient air to the plant if the piping is properly sized.

Estimated annual energy savings for the Reduce Compressed Air System Pressure measure are 7,901

kWh, for total estimated cost savings of $452 per year. First-order estimate of cost to implement this

measure is $100, for an estimated simple payback of 0.2 years.

This measure is a special or custom project and must be pre-approved by MidAmerican, subject to a

technical review to be performed by Nexant. However, since the potential energy cost savings from this

project exceed the estimated cost of implementing the project, the project is not eligible for a rebate; and

the City of West Des Moines will immediately begin saving an estimated $452 per year. Please complete,

sign and return a PIN form with a copy of the paid invoice for work done to implement this project and

MidAmerican will report the annual energy savings to the State.

4.2.3 Install LED Exit Signs

There were five exit signs observed during the walk through that used fluorescent lamps. The exact

wattage of the lamps was not determined, however, the wattage was estimated to be 16 watts per fixture

based on information provided by facility personnel. LED exit signs are available that will reduce the

per-fixture wattage to 2 watts or less, while still providing the same exit sign illumination. The five

existing fixtures with fluorescent lamps should be replaced with new LED exit sign fixtures.

Estimated annual energy savings for the Install LED Exit Signs measure are 613 kWh, for total estimated

cost savings of $33 per year. First-order estimate of cost to install this measure is $750, for an estimated

simple payback of 22.7 years prior to any incentives available from MidAmerican.


completed PIN form with a copy of the paid invoice for the purchase and installation of the LED exit

signs is required to receive the rebate. Please complete, sign and return the form with a copy of the paid

invoice to Nexant for processing.

4.2.4 Optimize Air-side Dry-bulb Economizer Controls

Air-side economizers are a great source for energy conservation and can be utilized several different

ways. One way to utilize an economizer on an air handling unit is to enable the economizer mode when

the outside air temperature falls below a dry-bulb temperature setpoint. This is commonly known as a

dry-bulb economizer control strategy. When the outside air temperature drops below this predetermined

setpoint, the mixed air dampers associated with the air handling unit will operate to maintain a mixed air

temperature equal to the discharge air temperature setpoint (typically 55°F for most commercial HVAC

systems). In lieu of using 100 percent mechanical cooling to maintain the discharge air temperature

setpoint, the outside air is used and allows for free cooling, or reduced mechanical cooling.

Area 2 Air handling unit is currently operating at maximum of 50% outside air with a dry-bulb

economizer switchover setpoint of 60°F and should be modified for a higher dry-bulb economizer

switchover setpoint. This measure proposes to reset the dry-bulb economizer switchover setpoint to 65°F

and utilize more outside air during the economizing mode. Implementation of this measure will consist of

modifying the existing economizer control programming and possibly calibrating the outdoor air

temperature sensor. This work can be done by a local temperature controls contractor.

Savings were determined based on an outside air dry-bulb temperature setpoint of 65°F. If desired, an



enthalpy economizer control strategy can be implemented for additional energy savings. Estimated

annual energy savings for the Optimize Air-side Dry-bulb Economizer Controls measure are 2,357 kWh,

for total estimated cost savings of $131 per year. First-order estimate of cost to implement this measure is

$700, for an estimated simple payback of 5.3 years prior to any incentives available from MidAmerican.


technical review to be performed by Nexant. If the project qualifies, it will be eligible for a $393 rebate,

leaving a simple payback of the project to 2.3 years. Please complete, sign and return the enclosed

Project Summary (PS) form to Nexant if the City of West Des Moines chooses to pursue this project.

4.2.5 Utilize Temperature Setback

The control system currently has a constant thermostat setpoint for each zone. HVAC energy use would

decrease if a temperature setback was programmed into the control system, which would automatically

adjust the space temperature setpoint during unoccupied hours (nights and weekends). The control

system is programmed to reduce the space temperature during unoccupied hours in the winter months.

Since there is less temperature difference between the space and the outdoors, there is less heat transfer

and a savings can be realized for heating.

Nexant recommends programming all zones with a temperature setback. During occupied hours, the

thermostats setpoint should remain at 70°F for the heating season. During the winter unoccupied hours,

the temperature should be set back to 62°F. The programming should not change the ventilation

setpoints and schedules of the air handling units.

Estimated annual energy savings for the Utilize Temperature Setback measure are 6,802 kWh and 4,386

therms, for total estimated cost savings of $3,779 per year. First-order estimate of cost to implement this

measure is $500, for an estimated simple payback of 0.1 years.


technical review to be performed by Nexant. However, since the potential energy cost savings from this

project exceed the estimated cost of implementing the project, the project is not eligible for a rebate; and

the City of West Des Moines will immediately begin saving an estimated $3,779 per year. Please

complete, sign and return a PIN form with a copy of the paid invoice for work done to implement this

project and MidAmerican will report the annual energy savings to the State.

4.3 Capital Investment Project Opportunities

Capital investment measures are defined as energy conservation, energy efficiency, or time-of-use

management projects with a capital cost of greater than $1,000. These measures significantly reduce

energy consumption and costs, but also require significant capital investment.

4.3.1 Replace HID Lighting with High-Bay Fluorescent

The garage is lighted with fifty-eight (58) 400-watt metal halide high-bay fixtures. Nexant recommends

replacing the existing fixtures with 6-lamp high-bay T8 fluorescent fixtures. The replacement high-bay

fluorescent fixtures use approximately 50 percent of the energy while providing a similar amount of light

as the existing fixtures. In addition, the fluorescent lighting does not have the slow warm-up time and

high lumen depreciation of metal halide lighting.

Estimated annual energy savings for the Replace HID Lighting with High-Bay Fluorescent measure are

73,136 kWh, for total estimated cost savings of $4,365 per year. First-order estimate of cost to install this

measure is $15,950, for an estimated simple payback of 3.7 years prior to any incentives available from

MidAmerican.

This measure is eligible for a of $4,872 rebate from MidAmerican based upon the reported opportunities.

A completed PIN form with a copy of the paid invoice for the purchase and installation of the upgraded



lighting is required to receive the rebate. Please complete, sign and return the form with a copy of the

paid invoice to Nexant for processing.

4.3.2 Upgrade T12 Fluorescent to T8 Fluorescent Lighting

Some of the areas are lighted with T12 fluorescent lamps with magnetic ballasts. Nexant recommends

retrofitting these T12 fixtures with T8 lamps and electronic ballasts. In addition to the energy savings,

most people find the color of the light produced by T8 lamps to be much more pleasing and natural.

Based on the count performed during the walk-through, ninty-eight (98) 4-foot, two-lamp T12 fixtures,

nine (9) 4-foot, four-lamp T12 fixtures and eighteen (18) 8-foot, two-lamp T12 fixtures can be upgraded.

As the T8 lamps have a higher light output than the T12 lamps, it is recommended to use a reduced-light

output ballast to more accurately match light levels and reduce energy consumption.

Estimated annual energy savings for the Upgrade T12 Fluorescent to T8 Fluorescent Lighting measure

are 9,438 kWh, for total estimated cost savings of $621 per year. First-order estimate of cost to install

this measure is $7,820, for an estimated simple payback of 12.6 years prior to any incentives available

from MidAmerican.

This measure is eligible for a of $1,296 rebate from MidAmerican based upon the reported opportunities.

A completed PIN form with a copy of the paid invoice for the purchase and installation of the upgraded

lighting is required to receive the rebate. Please complete, sign and return the form with a copy of the paid


4.3.3 Install Lighting Occupancy Sensors

Several areas in the Public Works building could benefit from the installation of occupancy sensor

controls, which reduce energy consumption by turning lights off when the areas are unoccupied.

Occupancy sensors use infrared and/or ultrasonic motion sensing technology to turn lighting fixtures on

or off based on the sensed presence or absence of an occupant in the space. Areas where occupancy

sensors should be installed include private offices, conference rooms, and break rooms.

The most common occupancy installation simply replaces the existing light switch. However, some

rooms may require a ceiling mounted sensor for reliable operation, which may increase the installed cost.

Also, rooms with three-way switches may require slightly more expensive sensors to work properly. The

estimates here are based on what was observed during the walk-through and the recommendations for

specific rooms are shown in Table 12 of the Appendix.

Estimated annual energy savings for the Install Lighting Occupancy Sensors measure are 7,493 kWh, for

total estimated cost savings of $344 per year. First-order estimate of cost to install this measure is $2,485,

for an estimated simple payback of 7.2 years prior to any incentives available from MidAmerican.


completed PIN form with a copy of the paid invoice for the purchase and installation of the occupancy

sensors is required to receive the rebate. Please complete, sign and return the form with a copy of the paid


4.3.4 Replace Existing Equipment with High Efficiency

There are three cooling units that have been used for at least 15 years. According to the 2005 Database

for Energy-Efficient Resources published by the California Public Utilities Commission, the specified

useful life for these types of cooling unitsis approximately 15 years. These units have either reached the

end of their useful life, or exceeded their useful life expectancy. Nexant suggests replacing the equipment

with high efficiency models when the units fail.

Table 3 below lists the equipment recommended for replacement, as well as each unit’s specified

remaining useful life, the standard or minimum efficiency of the unit, and the suggested minimum



efficiency of a high-efficiency replacement for that unit.

Table 3: Remaining Equipment Life and Efficiency Comparison (Source: California Public Utilities Commission, 2005 Database for Energy-Efficient Resources)

Equipment Equipment

Size

Equipment Age

(Years)

Remaining

Equipment Life

(years)

Standard

Efficiency

High

Efficiency

South Area

Office

(Unit #1)

5 Tons 23 Reached the

Standard

Equipment Life

9.7 EER 15 EER

Men’s

Locker

Room

(Unit #2)

3.5 Tons 15 Reached the

Standard

Equipment Life

9.7 EER 15 EER

Common

Area

(Unit #3)

4 Tons 22 Reached the

Standard

Equipment Life

9.7 EER 15 EER

Note that for this measure, the first-order cost estimate is based on the difference in cost between a

standard efficiency unit and a high efficiency unit, not on the full replacement costs of the units.

Estimated annual energy savings for the Replace Existing Equipment with High Efficiency measure are

17,957 kWh, for total estimated cost savings of $1,033 per year. First-order estimate of cost to install this

measure is $2,040, for an estimated simple payback of 2.0 years prior to any incentives available from

MidAmerican.


completed PIN form with a copy of the paid invoice for the purchase and installation of the high

efficiency equipment is required to receive the rebate. Please complete, sign and return the form with a

copy of the paid invoice to Nexant for processing.



4.4 Other Opportunities

An additional opportunity was identified during the walk-through, but they have not been included in the

above sections for one of the following reasons:

The project requires additional investigation before it can be recommended for installation.

The project’s energy cost savings do not justify the investment (the simple payback is high). The

City of West Des Moines is still encouraged to consider these projects if they feel they meet their

merits outside of cost savings.

The project only has gas savings, and since the facility does not purchase gas from MidAmerican,

incentives are not available for the identified projects.

4.4.1 Reduce Hot Water Temperature Set-Point

Rheem 50 gallon gas fired domestic hot water heaters are used in Area 2 and 4. The hot water

temperature was measured at 160°F during the walk-through. Nexant recommends reducing the hot water

temperature set-point to 140°F.

Reducing the hot water temperature slows mineral buildup and corrosion in the water heaters and pipes.

This helps the water heater last longer and operate at its maximum efficiency. As an energy savings rule

of thumb, the Public Works building can save between 3 – 5 percent in hot water heating costs for each

10ºF reduction in water temperature. The domestic hot water heaters’ natural gas consumption was

estimated to be reduced by six percent.



Section 5 Conclusion

MidAmerican Energy recommends that the City of West Des Moines continue their energy savings

efforts. The next steps to continue your participation in MidAmerican Energy’s EnergyAdvantage

Programs are the following:

Schedule a meeting with MidAmerican and Nexant to review the walk-through assessment report.

Begin to request and obtain vendor quotes for completing the proposed projects that the City of

West Des Moines is interested in implementing. After quotes have been received, the actual

eligible rebates can be quantified (eligible rebates will be the same as those identified in the

Nonresidential Equipment brochures and rebates for Custom System projects require technical

review for determination of eligible incentives). At that time, the actual savings, costs and

available incentives for the proposed projects can be reviewed and decisions whether or not to

proceed can be finalized. NOTE: Custom Systems projects and Nonresidential Equipment

rebates exceeding pre-defined values (see terms and conditions in the Nonresidential Equipment

rebate brochures) require MidAmerican pre-approval prior to project implementation.

For more information on eligible rebates, MidAmerican’s Nonresidential Equipment and Custom

Systems brochures are available on the internet; please visit http://www.midamericanenergy.com,

click on Energy Efficiency, and look for the EnergyAdvantage For Your Business link on the

left-hand side.

Install the selected energy conservation measures and apply for eligible rebates using the

provided Project Summary (PS) form and Project Installation Notice (PIN) as summarized for

each energy conservation measure in Section 4. For recommended Detailed Studies, please

complete the attached Detailed Study Request (DSR) form.

Contact Nexant with any questions that you may have in regards to understanding eligible rebates

and completing and submitting rebate forms. Completed forms should be emailed or faxed to:

(please do not complete and send the applications in the Nonresidential Equipment and Custom

Systems brochures to the provided mail to address or fax to number listed):

o FAX: 608-829-2723

o EMAIL: [email protected]

MidAmerican Energy City of West Des Moines – Public Works Page A


Section 6 Appendix

Table 4: Detailed Energy Project Opportunities Summary

ID Type* Name

Peak

Summer

kW

Electricity

[kWh]

Natural Gas

[therms]

Electricity

[$]

Natural Gas

[$]

Total

[$]

Estimated

Installed

Cost

Simple

Payback

(years)

Estimated

Incentive

Simple

Payback

(years)

1 LC

Install Vending

Machine Controls 0.0 2,100 0 $96 $0 $96 $440 4.6 $100 3.5

2 LC

Reduce Compressed

Air System Pressure 1.3 7,901 0 $452 $0 $452 $100 0.2 $0 0.2

3 LC Install LED Exit Signs 0.1 613 0 $33 $0 $33 $750 22.7 $25 22.0

4 LC

Optimize Air-side Dry-

bulb Economizer

Controls 0.0 2,357 0 $131 $0 $131 $700 5.3 $393 2.3

5 LC

Utilize Temperature

Setback 0.0 6,802 4,386 $270 $3,509 $3,779 $500 0.1 $0 0.1

6 CI

Replace HID Lighting

w ith High-Bay

Fluorescent 12.9 73,136 0 $4,365 $0 $4,365 $15,950 3.7 $4,872 2.5

7 CI

Upgrade T12

Fluorescent to T8

Fluorescent Lighting 2.7 9,438 0 $621 $0 $621 $7,820 12.6 $1,296 10.5

8 CI

Install Lighting

Occupancy Sensors 0.0 7,493 0 $344 $0 $344 $2,485 7.2 $180 6.7

9 CI

Replace Existing

Equipment w ith High

Efficiency 0.0 17,957 0 $1,033 $0 $1,033 $2,040 2.0 $600 1.4

Total 16.9 127,798 4,386 $7,345 $3,509 $10,854 $30,785 2.8 $7,466 2.1

*DS - Detailed Study, LC - Low -Cost Opportunity, CI - Capital Investment Opportunity

Measure DescriptionStandard

MidAmerican Estimated Annual Energy and Cost Savings with Installed Costs

MidAmerican Energy City of West Des Moines – Public Works Page B


Table 5: Assumptions and Calculations - Install Vending Machine Controls

Quantity

Building

Schedule

Unit Savings

(kWh) Unit Cost

Total Savings

(kWh) Total Cost

Beverage Machines 2 7 day/week 900 180$ 1,800 360$

Snack Machines 1 7 day/week 300 80$ 300 80$

Totals 2,100 440$

State: Iowa

Annual kWh Savings 2,100

Monthly kW Savings -

Annual Cost Savings 96$

Project Cost 440$

Simple Payback 4.6

Prescriptive Rebate 100$

Vending Machine Controls

Cost Summary

MidAmerican Energy City of West Des Moines – Public Works Page C


Table 6: Assumptions and Calculations - Reduce Compressed Air System Pressure

Notes

Compressor horsepower 10 Manufacturer BHP at full load

Motor Efficiency 82.5%

Motor Load Factor 95% Typically over 90% for compressors

Capacity Factor 70% Percent time Comp. is at full load

Motor Peak kW 8.6

Annual Run Hours 8,760 8 hours/day, 60 days/year

Annual Base kWh 52,676

Current System Pressure (psi) 160 Compressor is set to 130 psig

Maximum Pressure Required (psi) 120 Assumption

Recommended System Pressure (psi) 130 Savings per 1 psi decrease 0.5%

Total Savings 15.0%

Peak kW Savings 1.29

Annual kWh Savings 7,901

Summary

Total kW Reduction 1.29

Total kWh Reduction 7,901

Annual Cost Savings 452$ Total Estimated Cost 100$

Simple Payback 0.2

Reduce Compressed Air System Pressure

The pressure should be set slightly higher than

the end use regulator to account for pressure

drops and provide some system storage.

MidAmerican Energy City of West Des Moines – Public Works Page D


Table 7: Assumptions and Calculations - Install LED Exit Signs

Existing Exit Sign Notes

Fixture Wattage 16

Proposed LED Sign Notes

Fixture Wattage 2.0

Annual Operation Hours 8,760


Total kWh Reduction 123

Installed Fixture Cost 150$ Based on a new LED fixture

Prescriptive Rebate 5$ $5 per fixture Iowa 2009 Lighting

Estimated Number of Fixtures 5


Total kWh Reduction 613

Installed Fixture Cost 750$

Savings 33$

Simple Payback (years) 22.7

Prescriptive Rebate 25$

7 W bulb, Estimate is for two bulbs/fixture with

ballast

Projected Savings per Fixture

Prescriptive Rebate

Summary

MidAmerican Energy City of West Des Moines – Public Works Page E


Table 8: Assumptions and Calculations - Optimize Air-side Dry-bulb Economizer Controls Estimated AHU air flow rate varies linearly with OA temperature as follows

100% of design demand at 95 °F and higher

0% of design demand at 45 °F and lower Facility is running 0-50% OA

Existing economizer switchover setpoint 60 °F Enter "NA" if the air handling unit is not equipped with an air-side economizer.

Proposed dry-bulb economizer switchover setpoint 65 °F Recommended value is 65°F; refer to facility humidity requirements for better approximation.

setpoint

Nameplate Information Area 2 AHU Assumptions/Comments:

Supply fan motor horsepower rating 2 hp No VFD

Supply fan motor efficiency 80.5% %

Supply fan motor Load Factor 0.85

Operating Conditions

Total Supply Air Flow 1,400 CFM Assume 400 CFM per cooling ton

Discharge Air Temp setpoint (desired) 55 F

Return Air Temp 70 F

Return Air Relative Humdiity 55% %rh Recommended value is 55%rh; refer to facility requirements for better approximation.

Existing Minimum OA percentage 10% %

Calculated Data/Inputs

Air heat capacity 1.08 Btuh/cfm/F

ρhf g 4768

Elevation above sea level 830 feet

Atmospheric pressure, pa 14.2605 psia

Full Speed Supply Fan Demand 1.6 kW

Discharge Air Temp setpoint (required) 51 °F Required upstream of fan

Discharge Air Relative Humidity (required) 98% %rh Required upstream of fan

Supply air humidity ratio 0.0081 lbw/lbda Supply air humidity is determined based on leaving air temp off the cooling coil (design condition).

Supply air enthalpy 21.17 Btu/lbda Supply air enthalpy is determined based on leaving air temp off the cooling coil (design condition).

Supply air water vapor saturation pressure, pws 0.18794 psia

Supply air partial pressure of water vapor, pw 0.1842 psia

SA specific enthalpy for dry air, hda 12.35 Btu/lbda

SA specific enthalpy for saturated water vapor, hg 1083.84 Btu/lbda

Return Air Humidity Ratio 0.0088 lbw/lbda

Return air enthalpy 26.45 Btu/lbda

Return air water vapor saturation pressure, pws 0.36328 psia

Return air partial pressure of water vapor, pw 0.1998 psia

RA specific enthalpy for dry air, hda 16.80 Btu/lbda

RA specific enthalpy for saturated water vapor, hg 1092.08 Btu/lbda

Supply Fan and Motor Heat 5.37 MBH ASHRAE - Heat gain from typical electrical motors; motor in airstream, driven equipment in airstream

Cooling system efficiency 1.1 kW/ton Nameplate is missing, but it is an approximately 20 years old cooling unit.

Energy Consumption

Existing condition:

∙Heating - therms

∙Cooling 13,487 kWh

∙Peak Demand 2.9 kW

Proposed Condition:

∙Heating - therms

∙Cooling 11,130 kWh

∙Peak Demand 2.6 kW

Savings Summary

∙Gas savings - therms

∙Electric savings 2,357 kWh

∙Peak Demand Savings - kW

∙Annual electric savings $131 $/yr

∙Annual gas savings 0 $/yr

∙Estimated installed cost $700 (labor + materials)

∙Simple payback 5.3 year(s)

MidAmerican Energy City of West Des Moines – Public Works Page F


Table 9: Assumptions and Calculations - Utilize Temperature Setback

GIVEN CONDITIONS

Electricity usage during heating season 47,400 kWh

Fuel usage during heating season 30,565 Therm

Current daytime temperature 70 oF

Current night time temperature 70 oF

Proposed night time temperature 62 oF

TMY3 Dry Bulb BIN Data for DES MOINES INTL AP

DB Temperature BIN Occupied Unoccupied Total Occ BT*BH Unocc BT*BH

107.5 0.0 0 0 0 0

102.5 0.0 0 0 0 0

97.5 4.0 8 12 390 780

92.5 26.0 27 53 2405 2497.5

87.5 105.0 123 228 9187.5 10762.5

82.5 210.0 345 555 17325 28462.5

77.5 196.0 448 644 15190 34720

72.5 165.0 442 607 11962.5 32045

67.5 216.0 547 763 14580 36922.5

62.5 214.0 521 735 13375 32562.5

57.5 149.0 362 511 8567.5 20815

52.5 129.0 339 468 6772.5 17797.5

47.5 123.0 276 399 5842.5 13110

42.5 125.0 427 552 5312.5 18147.5

37.5 235.0 565 800 8812.5 21187.5

32.5 243 551 794 7897.5 17907.5

27.5 98 256 354 2695 7040

22.5 94 231 325 2115 5197.5

17.5 110 234 344 1925 4095

12.5 63 168 231 787.5 2100

7.5 53 133 186 397.5 997.5

2.5 24 80 104 60 200

-2.5 14 45 59 -35 -112.5

-7.5 14 22 36 -105 -165

-12.5 0 0 0 0 0

-17.5 0 0 0 0 0

-22.5 0 0 0 0 0

-27.5 0 0 0 0 0

-32.5 0 0 0 0 0

Heating Hours 1196 2988 4184

Occ Hr Unocc Hr Average

Average OA Temp 29.9 30.0 29.9

Therm/yr BTU/yr U*A kWh/yr BTU/yr U*A

Baseline 30,565 3,056,450,000 18,234 47,400 161,728,800 965

Proposed Occ Mode 8,755 13,578

Proposed Unocc Mode 17,423 27,020

Savings 4,386 6,802

% Savings 14% 14%

He

ati

ng

(W

he

n O

A <

50

F)

MidAmerican Energy City of West Des Moines – Public Works Page G


Table 10: Assumptions and Calculations - Replace HID Lighting with High-Bay Fluorescent

Fixture Type

No.

Fixtures

Watts/

Fixture

Annual

Hours Fixture Type

No.

Fixtures

Watts/

Fixture

# Occ.

Sensors

Occupancy

Sensor

Savings

Annual

Hours Peak kW

Annual

kWh

Installed

Cost/

Fixture

Installed

Cost/ Occ.

Sensor

Extended

Cost

Presc.

Rebate/

Fixture

Presc.

Rebate/

Occ. Sens

Extended

Rebate

Garage 400 W MH High-Bay 58 448 5,680

6-Lamp 4' T8 High-

Bay 58 226 5,680 12.9 73,136 $275 $15,950 $84 $0 $4,872

-

-

Totals: 58 58 12.9 73,136 $15,950 $4,872

Savings Summary

Peak kW Reduction 12.9

Annual kWh Reduction 73,136

Annual Cost Savings $4,365

Estimated Cost $15,950

Simple Payback 3.7

Prescriptive Rebate

Location

Baseline Proposed Energy Use Reduction Cost

MidAmerican Energy City of West Des Moines – Public Works Page H


Table 11: Assumptions and Calculations - Upgrade T12 Fluorescent to T8 Fluorescent Lighting

Fixture Type

No.

Fixtures

Watts/

Fixture

Annual

Hours Fixture Type

No.

Fixtures

Watts/

Fixture

# Occ.

Sensors

Occupancy

Sensor

Savings

Annual

Hours Peak kW

Annual

kWh

Installed

Cost/

Fixture

Installed

Cost/ Occ.

Sensor

Extended

Cost

Presc.

Rebate/

Fixture

Presc.

Rebate/

Occ. Sens

Extended

Rebate

Area 1 2-Lamp 4' T12 34W Lamp 11 72 2,600 2-Lamp 4' T8 RLO 11 51 2,600 0.2 601 $55 $605 $9 $0 $99

Area 2 2-Lamp 4' T12 34W Lamp 11 72 2,600 2-Lamp 4' T8 RLO 11 51 2,600 0.2 601 $55 $605 $9 $0 $99

Area 3 2-Lamp 4' T12 34W Lamp 50 72 2,600 2-Lamp 4' T8 RLO 50 51 2,600 1.1 2,730 $55 $2,750 $9 $0 $450

Area 3 4-Lamp 4' T12 34W Lamp 9 144 2,600 4-Lamp 4' T8 RLO 9 98 2,600 0.4 1,076 $80 $720 $18 $0 $162

Area 4 2-Lamp 8' T12 60W Lamp 18 123 5,680 2-Lamp 8' T8 NLO 18 110 5,680 0.2 1,329 $95 $1,710 $14 $0 $252

Area 4 2-Lamp 4' T12 34W Lamp 26 72 5,680 2-Lamp 4' T8 RLO 26 51 5,680 0.5 3,101 $55 $1,430 $9 $0 $234

Totals: 125 125 2.7 9,438 $7,820 $1,296

Savings Summary

Peak kW Reduction 2.7


Annual Cost Savings $621


Simple Payback 12.6

Prescriptive Rebate

Location

Baseline Proposed Energy Use Reduction Cost

MidAmerican Energy City of West Des Moines – Public Works Page I


Table 12: Assumptions and Calculations - Install Lighting Occupancy Sensors

4' T8 4' T12 8' T8 8' T12

Large conference room Conference 1 2,600 No 32 Ceiling Mount w/ Relay 200$ 200$ 896 390 349 20

Locker room Restroom 2 2,600 No 8 Wall Mount Dual Tech. 100$ 200$ 224 1,144 513 -

Break room Break Room 1 2,600 No 40 Wall Mount Dual Tech. 100$ 100$ 1,120 442 495 20

Traffic Offices Private Office 2 2,600 No 24 Wall Mount Passive IR 55$ 110$ 672 598 804 40

Private Offices @ Admin Bldg Private Office 9 2,600 No 12 Wall Mount Passive IR 55$ 495$ 336 598 1,808 -

Private Offices (Petersen) Private Office 1 2,600 No 8 Wall Mount Passive IR 55$ 55$ 224 598 134 -

Private Offices (Hodne) Private Office 1 2,600 No 32 Wall Mount Passive IR 55$ 55$ 896 598 536 20

Traffic Operation Center Private Office 1 2,600 No 16 Wall Mount Passive IR 55$ 55$ 448 598 268 20

Admin Assistant Private Office 1 2,600 No 32 Wall Mount Passive IR 55$ 55$ 896 598 536 20

Admin Secretary Private Office 1 2,600 No 16 Wall Mount Passive IR 55$ 55$ 448 598 268 20

Resource Center Break Room 1 2,600 No 40 Wall Mount Dual Tech. 100$ 100$ 1,120 442 495 20

Private Offices @ Trailer Private Office 7 2,600 No 4 Wall Mount Passive IR 55$ 385$ 144 598 603 -

Cenference Room @ Trailer Conference 1 2,600 No 8 Ceiling Mount w/ Relay 200$ 200$ 288 390 112 -

Cenference Room @ Trailer Conference 1 2,600 No 4 Ceiling Mount w/ Relay 200$ 200$ 144 390 56 -

Private Offices @ Trailer Private Office 4 2,600 No 6 Wall Mount Passive IR 55$ 220$ 216 598 517 -

- -

- -

Totals 34 2,485 7,493 180

(1) Occupancy sensor savings based on academic paper: VonNeida, B. Maniccia, D. and Tw eed, A. An analysis of the energy and cost savings potential of occupancy sensors for commercial lighting systems. Lighting Research Center & U.S. EPA. 2000.

Peak kW Reduction -


Savings 344$

Installed Cost 2,485$

Simple Payback (years) 7.2

Total Prescriptive Rebate 180$

Total Cost

Connected

Watts

/Room

Reduced

Lighting

Hours (1)

Annual

kWh

Reduction

Prescriptive

Incentive

Summary

Location Space Type

Quantity

of Rooms

Regular

Building

Hours

Lights Left

On at

Night?

Connected Lamps/Room Recommended Sensor

Type

Installed

Sensor

Cost

MidAmerican Energy City of West Des Moines – Public Works Page J


Table 13: Assumptions and Calculations - Replace Existing Equipment with High Efficiency

Note:

(1) Data are adapted from California Public Utilities Commission, 2005 Database for Energy-Efficient Resources, Version 2005.2.01, October 26, 2005

(2) 10% infalted incremental equipment costs are used in the calculator

Description Description

Packaged_AC

Packaged unitary system A/C (< 65k, 15 EER,

3 phase)

South area office

(unit #1) 23 15 4108 80% 5 Ton

A/C 9.7

SEER, no 9.7 EER

15 EER three

phase package 15 EER $ 163.19 per Ton

Reached the Standard

Equipment Life 815.96$ 7,183 kWh 1.75

Packaged_AC


3 phase)

Men's Locker room

(unit #2) 15 15 4108 80% 3.5 Ton

A/C 9.7

SEER, no 9.7 EER

15 EER three




Packaged_AC


3 phase)

Common Area

(unit #3) 22 15 4108 80% 4 Ton

A/C 9.7

SEER, no 9.7 EER

15 EER three




#VALUE! 0.00

#VALUE! 0.00

Savings Summary

Peak kW Reduction -


Annual Therm Reduction -

Annual Electricity Cost Savings $1,033

Annual Natural Gas Cost Savings $0


Simple Payback 2.0

Equipment Type Equipment Size and Details

Equipment

Label

Equipment

Age

Standard

Equipment

Life

Peak

Savings

(kW) Efficiency Efficiency

Annual

Operation

Hours

Average

% Load

Over

Time

Number of

Units

Baseline (Standard Efficiency) Proposed (High Efficiency)

Unit Incremental

Cost

Remaining

Equipment Life

(Years)

Total

Incremental

Project Cost

Annual Energy

Saving

Exhibit D

*EPA Energy Star Buildings benchmarking data 1

EfficiencyPartners® - SITE INFORMATION FORM Name: Linda Schemmel Title: Planner - City of West Des Moines E-mail Address: [email protected] Business/Cell Phone: 515-222-3620 Building Name & Address: Fire Station #17 – 1401 Railroad Avenue, WDM, IA

Building Information

Characteristic Description

1. Year of construction 1991

2. Building use (e.g. office, school, hospital) Fire Station/EMS

3. Number of occupants 2 staff @ 24/7, occasional meetings up to 50 people

4. Number of personal computers in operation (approx.)* 7

5. Annual occupancy rate of primary space by year*

Year Rate (% full)

2006 100

2007 100

2008

6. Building occupied for 11 or more of last 12 months?* Yes

Square Footage %Heated/

Cooled

7. Gross area (gross square footage)* 18,000 100 78

8. Percent of gross area designated as prime office space* 22% (4,000) 100 100

9. Percent of gross area designated as warehouse space Truck bay 78% (14,000) 100 0

10. Percent of gross area designated as manufacturing space

11. Weekly hours of operation by major space type*

Space Type Hours

Fire station 168

12. Brief renovation history (Attach separate sheet as required) Misc. repairs for water leakage

13. Brief description of building/energy improvements planned (Attach separate sheet as required).

None planned

14. Type of cooling system (e.g. Chiller, packaged A/C)

15. HVAC distribution system (e.g. constant volume, variable volume, dual duct, multi-zone)

16. HVAC control system type (e.g. pneumatic, DDC)

17. Building meter and account number

18. Permission to access 2 years of meter data Yes


[email protected]

Fax: 608-829-2723

Please complete the following table listing the facilities major HVAC and lighting system components. Add more rows as necessary or attach a separate equipment list.


Cooling Equipment

MCQUAM CONDENSER 208 VOLT 26-1/2 TON

1991

LENNOX PULSE CONDENSER 208 VOLT 1-1/2 TON

1991

Heating Equipment

LENNOX PULSE FURNACE GAS 110 VOLT 50,000 BTU

1991

BRYAN BOILER MIN. BTU 300K BTU 700K

1991

WEATHER RITE MAKE UP AIR UNIT GAS 54,000 BTU 1991

CO RA VAC (6) RADIANT HEAT 60,000 BTU/EACH 1991

ROOF FANS (7) ELECTRIC 100 VOLT 1/4 TO 1/2 HP MOTORS

1991


MCQUAY AHU 7-1/2 HP MOTOR 1991

Lighting Systems

OFFICES 110 VOLT T-12

SOME 110 VOLT INCANDECENT

EQUIPMENT BAY (32) 120 VOLT 250 WATT

Domestic Hot Water

RHEEM/RUUD WATER HEATER GAS 199,900 BTU 76 GALLON

2005

Motors (Over 5 HP)

AHU LISTED ABOVE MAGNATECH FAN MOTOR 7-1/2 HP 1991

If a manufacturer:

1. Attach list of major manufacturing equipment (e.g. compressed air system, motors, furnaces, etc.) with operating hours, or

2. Attach Iowa Energy Sales Tax Exemption data listing equipment sizes and hours of operation

LSchemmel

Typewritten Text

Exhibit E

LSchemmel

Typewritten Text

LSchemmel

Typewritten Text

LSchemmel

Typewritten Text

LSchemmel

Typewritten Text

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