TEXAS LoanSTAR PROGRAM

ENERGY ASSESSMENT REPORT

FOR

        Texas A&M University - Kingsville

1255 Retama Drive

Kingsville, TX 78363

 

Conducted by:

Shah Smith & Associates, Inc.

2825 Wilcrest, Suite 350

Phone:  (713)780-7563

Fax:  (713)780-9209

 

September 25, 1997

Number of Buildings:  32

Total Gross Square Footage:  1,424,000

TABLE OF CONTENTS

 

                                                                                                                                    Page

COVER SHEET                                                                                                                                                       1

TABLE OF CONTENTS                                                                                                                                        2

PREFACE                                                                                                                     3

      BACKGROUND                                                                                                     3       

      SUMMARY NARRATIVE                                                                                      3

      ACKNOWLEDGMENTS                                                                                       3

EXECUTIVE SUMMARY                                                                                          4

      BUILDINGS/FACILITIES ANALYSIS                                                                  4

      FIGURE 1 – CAMPUS MAP                                                                                  5

      COMPOSITE PROJECT SUMMARY                                                                    6

      SUMMARY OF PROJECT                                                                                     8

      TABLE 1 - SUMMARY OF INDIVIDUAL ECRMs                                               9

BASE YEAR ENERGY CONSUMPTION AND COSTS                                       10

      TABLE 2 - BASE YEAR ENERGY CONSUMPTION DATA                             10

METERING INFORMATION                                                                                11

      TABLE 3 - METER DATA                                                                                    11

 

UTILITY RATE SCHEDULE ANALYSIS                                                              12

      ELECTRIC UTILITY RATE SCHEDULE ANALYSIS                                         12

      GAS UTILITY RATE SCHEDULE ANALYSIS                                                   15

FACILITY DESCRIPTIONS                                                                                    16

      FACILITY DESCRIPTION                                                                                   16

TECHNICAL ANALYSIS                                                                                         21

      ECRM No. 1                                                                                                          21

      ECRM No. 2                                                                                                          23

      ECRM No. 3                                                                                                          24

      ECRM No. 4                                                                                                          25

      ECRM No. 5                                                                                                          27

      ECRM No. 6                                                                                                          28

ANALYST CERTIFICATION                                                                                  29

APPENDICES

      Appendix A – Savings Calculations

      Appendix B – Electric Bills

      Appendix C – Electric Rates/Rebates

      Appendix D – Gas Bills

      Appendix E – Trace Input

      Appendix F – Trace Output

      Appendix G – Existing Building Data

      Appendix H - KY Pipe Data

      Appendix I  – January/February Electric Load Profile

      Appendix J – ECRM Cost Estimates

PREFACE

BACKGROUND

The Texas A&M University – Kingsville (TAMU-K) campus has thirty-three (33) buildings which are currently being cooled and/or heated from two central plants (see Figure 1).  Of these, twenty(20) buildings are being served via a two-pipe hydronic system.  This two pipe system not only limits the university’s ability to control building comfort but it costs additional energy in the switchover process by heating up chilled water and cooling down heating water.

The two existing central plants have a combined installed capacity of 4500 tons.  The chillers range in age from 21 to 38 years and utilize R-11 (CFC) as the refrigerant.  TAMU-K indicates that the average chiller efficiency is 0.90 kW/ton, which is based on field measurements.

The existing pumping system consists of primary pumps located in the two central plants and secondary pumps located in the individual buildings.  In some buildings, the secondary pumps have been removed and the primary pumps are utilized to pump through those building.  Most buildings on the system utilize 3-way valves to bypass the coils during times of low demand.  This essentially creates a constant volume system and does not allow for reduction in pumping energy at times of low load.

TAMU-K has initiated the “Campus HVAC System Improvements Project” which is intended to implement the recommended Energy Cost Reduction Measures (ECRMs) as well as other work, but the available funding will not cover the estimated project cost.  However, TAMU-K has sufficient funding to buy down the cost of the ECRMs to the composite 8 year payback limit.

Shah Smith & Associates, Inc. has been selected to analyze the following Energy Cost Reduction Measures:

1.                        Install electric heat in buildings currently served from two-pipe system.

2.                        Replace all existing chillers with more efficient chillers (5 – 625 ton, non-CFC chillers).

3.                        Replace 3-way valves with 2-way valves.

4.                        Install variable frequency drives (VFD) on the primary distribution pumps.

5.                        Install a campus energy management system (EMS).

6.                        Install a thermal energy storage system.

SUMMARY NARRATIVE

This study was performed under the Texas LoanSTAR Program guidelines as administered by the State Energy Conservation Office.  The purpose is to identify energy cost reduction measures (ECRMs) which, when implemented, will result in significant energy cost savings for the borrower.  The savings calculations are made using sound, accepted fundamentals of engineering and current utility rate schedules.

ACKNOWLEDGMENTS

The staff of Shah Smith and Associates, Inc. would like to extend its thanks and appreciation to Texas A&M University - Kingsville and the Texas A&M University System and their staffs for assistance on the procurement of building data and operation schedules.  Special thanks to Mr. E. Ervin Linnstaedter, Texas A&M System Mechanical Engineer,  for devoting time, insight and resources.  Further thanks are extended to Mr. Buck Shaw, Assistant Director of Physical Plant and other operation and maintenance personnel for their support and helpfulness.

TEXAS LoanSTAR PROGRAM

 

Energy Assessment Report of

Texas A&M University - Kingsville

Contact Person:  Mr. Emil Ervin Linnstaedter, System Mechanical Engineer

The Texas A&M University System

Facilities Planning Division

UMS Box 1586

College Station, TX 77843

Phone:  (409)845-8857

 

EXECUTIVE SUMMARY

 

BUILDINGS/FACILITIES ANALYZED

 

This Energy Cost Reduction Analysis applies to the two central plants and to the campus buildings that currently receive their thermal utilities from them.

FI #	Bldg Name	Bldg Type	Bldg Area (Sq. Ft.)
501	College Hall	Administration	49999
502	Manning Hall	Classroom	44989
503	Hill Hall	Classroom	24223
505	Speech/Music	Classroom	41792
506	Bailey Art ('88)	Classroom	11707
507	Nierman Hall	Classroom	41288
509	Human Sciences (Home Econ.)	Classroom	19852
512	Kleberg Engineering Hall	Classroom	41254
517	Kleberg Bldg for Agriculture	Classroom	21203
520	Art Addition ('72)	Classroom	9498
521	ROTC Bldg	Classroom	11264
523	Fore Hall	Classroom	23312
524	Biology & Earth Science Hall	Classroom	41705
525	Health & Rec. Bldg	Activity	32436
526	Jernigan Library	Student Services	140147
527	Gross Industrial Arts	Classroom	21469
528	Steinke PE Center	Activ./Spec. Events	99034
533	Rhode Hall	Classroom	76032
535	Business Admin	Classroom	42595
543	Dotterweich	Classroom	12781
544	Howe Ag Bldg	Classroom	21913
550	McNeil Engineering	Classroom	14873
600	Jones Auditorium	Special Events	23020
700	Student Health	Student Services	6194
725	Student U/Bookstore	Student Services	91887
745	Lewis Hall	Dormitory	60064
746	Eckhardt Hall	Dormitory	19868
747	Poteet Hall	Dormitory	71648
748	Lynch Hall	Dormitory	47391
749	Martin Hall	Dormitory	87650
750	Bee County(now Health/Wellness)	Classroom	9240
752	Turner-Bishop	Dormitory	163370
603	Art Annex	Art Studio	2000

 

 

COMPOSITE PROJECT SUMMARY

ECRM No. 1:

Installation of electric heat to provide for simultaneous cooling and heating in the buildings currently served via a two-pipe hydronic system.  The affected buildings are listed below:

Hill Hall

Speech/Music

Bailey Art ('88)

Human Sciences (Home Econ.)

Kleberg Bldg for Agriculture

Art Addition ('72)

ROTC Bldg

Fore Hall

Biology & Earth Science Hall

Health & Rec. Bldg

Jones Auditorium

Student Health

Eckhardt Hall

Poteet Hall

Lynch Hall

College Hall

Lewis Hall

Art Annex

Martin Hall

Turner-Bishop

ECRM No. 2:

Replacement of all existing chillers in the two central plants with more efficient, non-CFC chillers.

ECRM No. 3:

Installation of Energy Management System (EMS) to efficiently control the electric heat installed under ECRM

No. 1.

ECRM No. 4:

Replace the majority of the 114 existing 3-way valves with 2-way valves at building AHUs to reduce pumping energy at low load conditions.  Some existing 3-way valves will remain in the system to maintain minimum flow requirements.  It is anticipated that 3-way valves will be replaced in the following buildings:

College Hall

Manning Hall

Hill Hall

Speech/Music

Bailey Art ('88)

Art Annex

Nierman Hall

Human Sciences (Home Econ.)

Kleberg Engineering Hall

Kleberg Bldg for Agriculture

Art Addition ('72)

ROTC Bldg

Fore Hall

Biology & Earth Science Hall

Health & Rec. Bldg

Jernigan Library

Gross Industrial Arts

Steinke PE Center

Business Admin

Dotterweich

Howe Ag Bldg

Jones Auditorium

Student Health

Lewis Hall

Eckhardt Hall

Poteet Hall

Lynch Hall

Martin Hall

Bee County

Rhode Hall

Bookstore

ECRM No. 5:

Install variable frequency drives on primary pumps located in the two central plants.  This ECRM does not appear to offer much savings above the savings realized by ECRM No. 4 listed above.  SSA does not recommend the implementation of this ECRM. 

ECRM No. 6:

Install a chilled water thermal energy storage system to transfer electrical demand to off-peak hours.  CP&L’s current rate structure does not encourage thermal storage.  SSA does not recommend the implementation of this ECRM.

		SUMMARY OF PROJECT
			Category III Total
KWh Savings:			2,643,876	kWh/yr
Demand Savings:			23,006	kW/yr
Gas Savings:			5,195	MCF/yr
Btu Savings:			36,020	MMBtu/yr
Cost Savings:			259,018	$/yr
Base Year Cost Red.:			16.9	%
Implementation Cost(1):			3,045,990	$
Simple Payback:			11.8	Years

Note:

(1)   Implementation cost has CP&L’s Rebate included.

This report identifies capital-intensive projects which, if implemented in the form recommended, will result in the savings and costs summarized above.  The savings for the recommended composite project listed above account for interdependence of savings of individual ECRMs.  Costs for the project likewise account for savings which accrue from installing several ECRMs at once and for utility rebates which will lower project cost.

SPECIAL CONSIDERATIONS

TAMU-K will contribute the funds required to buy down the project payback to the composite 8 year limit.  The required amount, $973,846, will come from funds already budgeted for the “Campus HVAC System Improvements Project”.

TABLE  1.  SUMMARY OF INDIVIDUAL ENERGY COST REDUCTION MEASURES

ECRM No.	ECRM Title	Annual Savings				Implementation Cost ($) (4)	Simple Payback  (yrs.)	Estimated Project Lifetime (yrs.)
		Electric Energy (kWh/yr.)	Demand   (kW/yr.)	Natural Gas   (MCF/yr.)	Cost   ($/yr.)
1	Install Electric Heat	(1)<542,760>	10,737	5,195	134,760	1,132,060	8.4	25
2	Replace Existing Chillers	2,395,876	10,337	0	97,836	(2)  1,594,000	16.3	25
3	Install EMS	0	1,036	0	11,200	159,430	14.2	25
4	Replace 3-way Valves	248,000	896	0	15,222	160,500	10.5	25
5	Install VFDs on Primary CHWPs	(3)  15,171	(3) 12	0	(3)  316	(3)  85,600	N/A	25
6	Install Thermal Storage	0	(3) 9652	0	(3) 91,665	(3)  856,000	N/A	25
TOTAL		2,643,876	23,006	5,195	259,018	3,045,990	11.8	25

Note:

(1)               Installation of electric heat will increase the amount of energy used per year.  Savings are realized from lower demand charges, less gas consumption,  and CP&L Rider 4.

(2)               Implementation cost includes CP&L’s rebate of approximately $57,500 ($18.40/ton).

(3)               ECRM is not recommended therefore this amount is not included in the totals below.

(4)               Implementation Cost includes 7% Engineering fee.

 

                                                                                                                                    Bldg. ID :  Entire Campus

TABLE  2.   BASE YEAR ENERGY CONSUMPTION DATA                                             Gross Square Footage:                                                             1,695,000 

For prior 12 month period beginning August, 1996 and ending  July, 1997                                                                                                                                

Historical Load Data
Month	Aug-96	Sep-96	Oct-96	Nov-96	Dec-96	Jan-97	Feb-97	Mar-97	Apr-97	May-97	Jun-97	Jul-97
Maximum Demand kW	6,039	6,181	6,342	5,921	5,524	4,084	5,248	5,256	5,413	5,482	5,745	5,933
KWh	3,132,900	3,242,100	3,381,600	3,122,700	2,272,500	2,058,000	2,100,300	2,293,200	2,405,100	2,628,300	3,141,300	3,246,900
Power Factor	95.3%	95.2%	94.9%	96.6%	98.6%	99.9%	99.6%	96.7%	96.0%	94.4%	92.6%	92.1%
State Institutional Service - 45
Billing kW (adjusted for PF)	5,911	6,052	6,218	5,765	5,334	3,922	5,046	5,115	5,283	5,386	5,685	5,883
Max Billing kW previous summer	6,218	6,218	6,218	6,218	6,218	6,218	6,218	6,218	6,218	6,218	6,218	6,218
Billing kW	5,911	6,052	6,218	5,765	5,334	4,974	5,046	5,115	5,283	5,386	5,685	5,883
Demand Charge, $13.13/kW	77,611	79,463	81,642	75,694	70,035	65,314	66,254	67,160	69,366	70,718	74,644	77,244
Energy Charge, $0.00779/kWh	24,405	25,256	26,343	24,326	17,703	16,032	16,361	17,864	18,736	20,474	24,471	25,293
Educational Institution Discount	-20,403	-20,944	-21,597	-20,004	-17,548	-16,269	-16,523	-17,005	-17,620	-18,239	-19,823	-20,507
Fuel Charge Rate, $/kWh	$0.013702	$0.013702	$0.013702	$0.013702	$0.013702	$0.015249	$0.015249	$0.017652	$0.017652	$0.017652	$0.017652	$0.015164
Fuel Charge	42,927	44,423	46,335	42,787	31,138	31,382	32,027	40,480	42,455	46,395	55,450	49,236
Gross Receipts Fee Adjustment	3,593	3,699	3,829	3,543	2,923	2,783	2,831	3,130	3,258	3,443	3,887	3,787
Transformer Rental	768	768	768	768	768	768	768	768	768	768	768	768
Facilities Rental	4,134	4,134	4,134	4,134	4,134	4,134	4,134	4,134	4,134	4,134	4,134	4,134
Total	133,035	136,799	141,454	131,248	109,154	104,144	105,852	116,531	121,096	127,694	143,531	139,955
Total Electric for Year	$1,510,494
Gas Heat
Gas MCF	0	0	0	0	657	2,361	2,177	0	0	0	0	0
Cost of gas, $/MCF	3.69	3.69	3.69	3.69	3.69	3.69	3.69	3.69	3.69	3.69	3.69	3.69
Total	0	0	0	0	2,424	8,712	8,033	0	0	0	0	0
Total Gas for Year	$19,170
Total Electric & Gas for Year	$1,529,663

	Electricity	Natural Gas	Other
Company Name:	Central Power & Light	General Land Office	Entex (Gas transportation)
Company Rate Schedule	Rate 45 with Rider 4

 

^*Certification:

Charges have been recomputed and are correct                                                                                                                       

METERING INFORMATION

 

TABLE  3.  METER DATA

Meter Number	Area Served
Electric   2224 12637 12637 (Reactive)	These two meters serve the facilities affected by the ECRMs.  The meters are combined on a single bill for electric service.  The resulting peak demand is actually the coincident peak demand and not the sum of the individual peak demands.
Natural Gas   417893 6070253 71729 2393257 (No longer in service) 5229992 (No longer in service)	Main Meter (Entire Campus except the following) Javelina Stadium Poteet Hall Athletic Office May Hall Area

UTILITY RATE SCHEDULE ANALYSIS

 

ELECTRIC UTILITY RATE SCHEDULE ANALYSIS

 

 

NAME OF UTILITY:

Central Power & Light (CP&L)

RATE SCHEDULE ANALYZED:

Rate 45 with Rider 4, Rider 30 & S-TOU (See Appendix C)

SUMMARY OF BILLING COMPONENT CHARGES:

State Institutional Service – 45
	Demand $/kW	$13.13
	Minimum Demand Charge	$3.54	per hp of largest motor
	Energy Charge	$0.00779
	Fuel Cost
	Demand = 15 minutes of max usage for month
	Minimum Demand = 80% of July-Oct peak
	Minimum Demand = 600 kW
	Power Factor > 90%:  decrease demand by 0.4% for each 1%
	Power Factor < 80%:  increase demand by 0.4% for each 1%
	Transmission Discount = $0.50 per kW if customer owns, operates, and maintains HV facilities
Space Heating – Rider 4
	Demand = greater of: (max measured demand for month or max measured demand for
	6 months preceding winter months) less 1 kW for each ton of HVAC
	Minimum Demand = 50% of measured demand for month
	Minimum Demand = 50% of peak demand in 6 months preceding winter months
	Maximum Demand = measured demand for present month
	Winter Months = November – April
State Educational Institution Discount – Rider 30
	20% off of base rate [kW & kWh], but not on fuel or rental charges
Base Rate Fixed Fuel Cost Factor (as of 8/26/97)
	January – February (primary) $/kWh	$0.015249
	March - June (primary)	$0.017652
	July (primary)	$0.015164
	August – December (primary) $/kWh	$0.013702

Select Time Of Use (S-TOU)
	On-Peak Season = June, July, Aug, Sept
	Off-Peak Season = Oct, Nov, Dec, Jan, Feb, Mar, Aprl, May
	On-Peak Hours:
	Narrow Window = 3:00 pm thru 7:00 pm weekdays during On-Peak Season
	Standard Window = 2:00 pm thru 8:00 pm weekdays during On-Peak Season
	Wide Window = 1:00 pm thru 9:00 pm weekdays during On-Peak Season
	Off-Peak Hours = all other hours + all Off-Peak Season Hours + July 4 + Labor Day

		Pricing	A	B	C
	Narrow Window	Pp	8.20	9.70	11.80	Cents/kWh
		Po	3.35	3.30	3.20	Cents/kWh
	Standard Window	Pp	8.20	9.70	11.80	Cents/kWh
		Po	3.25	3.15	3.00	Cents/kWh
	Wide Window	Pp	8.20	9.70	11.80	Cents/kWh
		Po	3.15	3.00	2.80	Cents/kWh

Monthly Bill = EC + DC + Pgm

Pgm = Program Charge = $10 per month

EC = Energy Charge = (kWho x Po) + kWhp x Pp)

kWho = Customer’s current actual monthly off-peak kWh usage

kWhp = Customer’s current actual monthly on-peak kWh usage

Po = Applicable monthly off-peak S-TOU price

Pp = Applicable monthly on-peak S-TOU price

DC = Delivery Charge = {Base Bill -[(kWho x Po) + (kWhp x Pp)]} / 12 months ; DC >= $0

kWho = Annual Customer User Profile off-peak kWh usage for 12 month period

kWhp = Annual Customer User Profile on-peak kWh usage for 12 month period

Po = Applicable off-peak S-TOU price for 12 month period

Pp = Applicable on-peak S-TOU price for 12 month period

Base Bill = Annual Customer Usage Profile under standard rate schedule and riders

AVOIDED COST OF ENERGY TO BE USED IN CALCULATIONS:

            Base Energy Charge less 20% Institutional Discount      =   $0.00779 x 0.8  =   $ 0.00623 per kWh used

       +   Average Fuel Charge                                                                  =        $ 0.01540 per kWh used           

            Base + Fuel Charge                                                                    =        $ 0.02163 per kWh used

       x   Gross Receipts Factor                                                                =        x 1.02885                   

            Avoided Cost of Energy                                                                         =        $ 0.02225 per kWh used

AVOIDED COST OF DEMAND TO BE USED IN CALCULATIONS:

            Demand Charge less 20% Institutional Discount              =  $13.13 x 0.8            =        $ 10.50               per kW

       x   Gross Receipts Factor                                                               =        x 1.02885                   

            Avoided Cost of Demand                                               =                      =        $ 10.80               per kW

COMMENTS:

Rider 4 - Space Heating

Rate 45 with Rider 4 is used to evaluate ECRM’s 1, 2, 3, 4, 5, and 6.  Rider 4 gives the customer a demand credit in the summer months which is proportional to the customer’s electric air conditioning capacity when the customer uses electricity for providing heat.  Since TAMU-K is installing electric heat which is ECRM 1, the remaining ECRM’s must be evaluated with Rider 4.

Select Time of Use (S-TOU)

S-TOU is the rate used to evaluate ECRM 6 in lieu of Rate 45.  At first look, it appears that the S-TOU rate encourages thermal energy storage by the fact that it has no demand component and that the energy charge (EC) during the off-peak hours is considerably less than the on-peak hours.  Further, the wider the on-peak window the customer selects, the lower the off-peak energy charge.  However, in addition to the energy charge there is a delivery charge (DC) which as stated in the rate is designed to achieve revenue neutrality with the customer’s standard rate schedule.  In other words, the delivery charge adds back into the bill the difference between the energy charge under S-TOU and the customer’s bill as would have been calculated under the customer’s previous rate for the previous year.  It appears that this rate would only offer savings to a customer that is expecting a large increase in electrical usage.

GAS UTILITY RATE SCHEDULE ANALYSIS

 

 

NAME OF UTILITY:

General Land Office for gas

Entex for transportation

RATE SCHEDULE ANALYZED:

SUMMARY OF BILLING COMPONENT CHARGES:

TAMU-K is billed for the quantity of gas used by the General Land Office.  It is billed for the delivery of that gas by Entex.  Entex bills are based on the quantity of gas delivered to TAMU-K.

AVOIDED COST OF ENERGY TO BE USED IN CALCULATIONS:

The cost of gas used in the analysis is the average cost of gas for the past 12 months which is $3.69/MCF.  Appendix  D contains tabulated monthly gas consumption data for January1993 through July 1997.

AVOIDED COST OF DEMAND TO BE USED IN CALCULATIONS:

Not Applicable.

COMMENTS:

FACILITY DESCRIPTIONS

 

The following is a brief summary of the existing conditions in each building affected by the ECRMs.  Refer to Appendix G for a detailed schedule of the existing building systems.

 

Lynch Hall

Lynch Hall is a two story building served from the two-pipe system.  This building contains six (6) multizone air handling units (AHUs) with face and bypass dampers and a total of 19 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Poteet Hall

Poteet Hall Unit A is a one story building served from the two-pipe system. Poteet Hall Unit B is a three story building also served from the two-pipe system.  This building contains two (2) multizone AHUs with face and bypass dampers and twelve (12) single zone AHUs for a total of 19 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No. 3).

Jernigan Library

Jernigan Library is a three story building containing four (4) double duct AHUs and electric heat.  Each AHU has a 3-way control valve.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Industrial Technology

Industrial Technology is a one story building served from the four-pipe system.  This building contains two (2) multizone AHUs and two (2) single zone AHUs with a total of 12 zones.  Each AHU has a 3-way control valve.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Eckhardt Hall

Eckhardt Hall is a two story building served from the two-pipe system.  This building contains 5 multizone AHUs and 1 single zone AHU with a total of 17 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); the electric heat will be controlled through the Energy Management System (ECRM No. 3).

Dotterweich Engineering Hall

Dotterweich Engineering Hall is a one story building with two AHUs.  AHU-1 (double duct) is served solely from the four-pipe system while AHU-2 (roof top, single zone) can be served from either the four-pipe system or a local chiller.  Each AHU has a 3-way control valve.

The 3-way valve for AHU-1 will be replaced with a 2-way valve (ECRM No. 4).  The 3-way valve at AHU-2 will remain if it is going to continue to operate with local chiller.

Student Union/Bookstore

The Student Union is a three story building that contains 17 AHUs and its own boilers.  All AHUs have 2-way valves.  The Bookstore is a one story building that receives hot water from the boilers in the Student Union and has 1 AHU with 3-way chilled water control valve.

The 3-way valve in the Bookstore will be replaced with a 2-way valve (ECRM No. 4).

Biology-Earth Science

Biology-Earth Science is a three story building served from the two-pipe system.  The building contains 1 single zone AHU and 2 multizone AHUs with a total of 15 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Kleberg Engineering Bldg

Kleberg Engineering is a one story building with 2 single zone AHUs and 2 Multizone AHUs with a total of 13 zones.  Each AHU has a 3-way control valve.  This building is served from the four-pipe system.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Steinke Physical Education Center

Steinke Physical Education Center is a 3 story building served from the four-pipe system.  The building contains 4 multizone AHUs and 6 single zone AHUs with a total of 30 zones.  Six of the AHUs have 3-way control valves.  The other four have 2-way valves.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

 

College Hall

College Hall is a three story building served from the two-pipe system.  The building contains 2 single zone AHUs (one with both a DX and chilled water coil) and 4 multizone AHUs with a total of 27 zones.  There are 5 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Bellamah Music

Bellamah Music is a two story building served from the two-pipe system.  The building contains 3 single zone AHUs and 3 multizone AHUs with a total of 10 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

 

Speech Bldg

Speech is a two story building served from the two-pipe system.  This building contains 1 single zone AHU and 1 multizone AHU with a total of 4 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Bailey Arts Bldg

Bailey Arts is a one story building served from the two-pipe system.  The building contains 1 multizone AHU with a total of 3 zones.  There is 1 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valve will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Art Addition

Art Addition is a 1 story building served from the two-pipe system.  The building contains 2 multizone AHUs with a total of 8 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

ROTC Bldg

ROTC is a one story building served from both the two-pipe and the four-pipe systems.  The building contains 1 multizone AHU (3 zones) and 2 single zone AHUs.  The multizone is the only AHU served from the two pipe system.  All AHUs have 3-way control valves.

An electric duct heater will be installed in 3 AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Fore Hall

Fore Hall is a two story building served from the two-pipe system.  This building contains 3 single zone AHUs and 1 multizone AHU with a total of 9 zones requiring electric heat.  Of the 3 single zone AHUs, one currently has electric heat.  Only one AHU has a 3-way control valve.

An electric duct heater will be installed in 3 AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Health & Recreation Bldg

Health & Recreation is a two story building served from the two-pipe system.  This building contains 1 single zone AHU and 2 multizone AHUs with a total of 11 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Martin Hall

Martin Hall is a three story building served from the two-pipe system.  This building contains 14 multizone AHUs with a total of 56 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Turner-Bishop Hall

Turner-Bishop Hall is a three story building served from the two-pipe system.  This building contains 16 multizone AHUs with a total of 71 zones.  Each AHU has a 2-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1) and the electric heat will be controlled through the Energy Management System (ECRM No.3).

 

Hill Hall

Hill Hall is a two story building served from the two-pipe system.  This building contains 6 single zone AHUs, however, 4 of the 6 will require two duct heaters due to duct splits (10 heaters total).  Each AHU has  a 3-way control valve.

 An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Nierman Hall

Nierman Hall is a two story building served from the two-pipe system.  This building is being renovated under a separate contract to install electric heat.  There are 5 AHUs, each with a 3-way control valve.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Howe Agriculture Bldg

Howe Agriculture is a two story building which contains a local boiler.  This building also contains 2 AHUs, each with 3-way control valves.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Business Administration

Business Administration is a two story building containing 4 multizone AHUs with existing electric heat.  Each of the AHUs has a 3-way control valve.

The 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Kleberg Agriculture Bldg

Kleberg Agriculture is a one story building served from the two-pipe system.  This building contains 3 single zone AHUs and 1 multizone AHU.  Each of the single zone AHUs will require two duct heaters due to duct splits.  Therefore, 10 heaters will be required.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Manning Hall

Manning Hall is a two story building served from the two pipe system.  This building is being renovated under a separate contract to install electric heat.  There are 8 multizone AHUs, each with 3-way control valves; the 3-way valves will be replaced with 2-way valves (ECRM No. 4).

Student Health Center

Student Health Center is a one story building served from the two-pipe system.  This building contains 1 multizone AHU with 4 zones and a 3-way control valve. 

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Human Sciences Bldg

Human Sciences is a one story building served from the two-pipe system.  This building contains 2 multizone AHUs with a total of 10 zones.  Each AHU has a 3-way control valve.

An electric duct heater will be installed in each of the AHU zones (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

Lewis Hall

Lewis Hall is a three story building served from the two-pipe system.  This building contains 7 multizone AHUs with a total of 16 zones and 3 single zones AHUs.  Nine of the ten AHUs have 3-way control valves.  The tenth AHU does not have a chilled water coil (DX & steam coils only).  This buildings also contains three steam boilers and a steam to hot water converter to produce its own heating water.  However, the AHUs only have one coil and they do not have the ability to simultaneously heat and cool.

An electric duct heater will be installed in each of the AHU zones which do not currently have a heating coil (ECRM No.1); the 3-way valves will be replaced with 2-way valves (ECRM No. 4); and the electric heat will be controlled through the Energy Management System (ECRM No.3).

TECHNICAL ANALYSIS

 

Note:  All calculations relevant to ECRM savings are in Appendix A.

 

ENERGY COST REDUCTION MEASURES (ECRMs) - DETAILED CALCULATIONS

 

ECRM NO.:  1

 

ECRM NAME:  Install Electric Heat

 

SUMMARY DATA (DEPENDENT)

 

                kWh Savings:                                <542,760>           kWh/Year

                Demand Savings:                          10,737                  kW/yr.

                Gas Savings:                                  5195                    MCF/yr.

                Cost Savings:                             $134,760               /yr.

                Implementation Cost:                $ 1,132,060            $

                Simple Payback:                            8.4                       Years

                Estimated Useful Life:                  25                        Years

 

ECRM No. 1 DESCRIPTION

There are 27 buildings connected to the two-pipe thermal distribution system.  Four of these buildings have heating water boilers; another six buildings have electric heat.  This means that as long as the two-pipe system is in the cooling mode, these 10 buildings can be heating or cooling as necessary.  The remaining 17 buildings will all cool or heat depending on the mode of the two-pipe system.  Further, when the two-pipe system is in the heating mode, the 10 buildings which have local heating capabilities cannot do any cooling.

There are 5 buildings connected to a pseudo-four-pipe system.  It is not a true four-pipe system in that the chilled water piping is served from the two-pipe system.  Therefore, when the two-pipe system is in heating mode, these 5 buildings receive all hot water.

The two-pipe system not only creates building comfort problems, it consumes a significant amount of energy to heat the chilled water when converting to heating and even more energy to cool the hot water when converting to cooling.  In an effort to increase their ability to better control building comfort and reduce the energy waste inherent to cycling between hot and cold water, TAMU-K is installing electric heat in the applicable buildings. 

The electric heat will increase the electricity consumption, but will reduce the gas consumption.  Typically, electric heat costs more on an energy basis; however, CP&L’s Rider 4, when applied, provides a net savings to TAMU-K.  Rider 4 gives the customer a demand credit for electric air conditioning when electric heat is used.  SSA prepared models of CP&L’s utility rates and used kW and kWh for the months of August 1996 through July 1997 as a base for comparing Rate 45 against Rate 45 with Rider 4.  Refer to Appendix A, pg. A-1 and A-2 for the cost comparison calculations labeled “Current Usage & Rate” and “Electric Heat with Rider 4”, respectively.   The savings are the difference between the annual electric and gas costs calculated in each model.

See Appendix B for monthly electric bills and Appendix C for CP&L Rates.

ECRM No. 1 ASSUMPTIONS

 

To determine the amount of gas utilized for building heat, SSA reviewed past utility bills and determined an average gas usage for non-heating months (March through November) and for heating months (December through February).  The difference was the amount of gas used for building heat.  Based on the total square footage of buildings heated by gas, SSA estimated that the buildings served from the existing two-pipe system comprised 74% of the total.

 

To determine the amount of additional electrical energy consumed by utilizing electric heat, SSA used the total installed heating kW and assumed 10 heating days at 24 hrs/day and a 50% average load during heating.  This assumption is based on the operating personnel’s experience that the two pipe system is in the heating mode 12 to 15 days per year, typically for half of each day.  Based on the foregoing, SSA estimated an annual heating energy requirement of 543,000 kWh for the buildings now served by the two pipe system.  This amount was apportioned between three heating months (December, January and February).

 

The impact of electrical heating demand will only apply to three months out of the year.  Even in these months, the maximum heating demand will never coincide with the peak campus electrical demand for the month.  The highest demand for heating will be early in the morning when the buildings are being heated up.  A review of time-of-day load data for January and February indicates that early morning loads are typically 2000-3000 kW less that the maximum monthly demand (see Appendix I).  Any heat demand up to this level will not increase the electrical demand cost.  By staging the startup of the building heat, it will be possible to minimize any contribution of heating loads to the monthly demand.  For purposes of this evaluation, we have assumed that the electrical demand kW for the months of December, January and February would increase by an amount equal to one third of the total electrical heating demand.

 

 

ECRM NO.:  2

 

ECRM NAME:  Replace Chillers

 

SUMMARY DATA (DEPENDENT)

 

                kWh Savings:                                2,395,876            kWh/Year

                Demand Savings:                          10,337                 kW/yr.

                Gas Savings:                                  0                          MCF/yr.

                Cost Savings:                             $97,836                 /yr.

                Implementation Cost:                $ 1,594,000            $

                Simple Payback:                            16.3                     Years

                Estimated Useful Life:                  25                        Years

 

ECRM No. 2 DESCRIPTION

 

TAMU-K currently has 4500 tons of chiller capacity divided between two central plants.  Central Plant 1 has 2-250 ton chillers, 1-500 ton chiller and 1-1000 ton chiller.  Central Plant 2 has 2-750 ton chillers and 1-1000 ton chiller.  The chillers range in age from 21 years to 38 years with an overall average age of 31 years.  TAMU-K indicates that the average chiller efficiency is 0.90 kW/ton which is based on field measurements.  All chillers use R-11.

TAMU-K has decided to replace these units with high efficiency non-CFC chillers.  Central Plant 1 will receive 2-625 ton units with space for a third future 625 ton chiller.  Central Plant 2 will get 3-625 ton chillers.  In total, TAMU-K will have 3125 tons* of chiller capacity.  The chillers will have a minimum efficiency of 0.62 kW/ton.

Currently TAMU-K’s peak cooling demand is estimated to be 2500 tons based on the operating personnel’s experience and the Trace analysis included in Appendix E (Input) and Appendix F (Output).  The Trace analysis also provided the thermal load profile for evaluating the savings from the new chillers.

Refer to Appendix A, pg. A-3 for savings calculations labeled “Improved Chiller Efficiency combined with Electric Heat under Rider 4”.  The savings are the difference between the annual electrical cost calculated in this model and the annual cost calculated for electric heat under ECRM No. 1 (Appendix A, pg. A-2 - “Electric Heat with Rider 4”). 

 

ECRM No. 2 ASSUMPTIONS

 

TAMU-K does not record thermal utility data for their chilled water system.  Therefore SSA used TRACE load calculation software to determine the thermal profile for the campus buildings served from the existing central plants.  From the campus profile, the monthly peak load and ton-hours were calculated for use in the savings calculations. 

 

 

* Central Plant 1 actually received 3-650T chillers as did Central Plant #2 for a total capacity of 3900 tons.

ECRM NO.:  3

 

ECRM NAME:  Install Energy Management System

 

SUMMARY DATA (DEPENDENT)

 

                kWh Savings:                                0                          kWh/Year

                Demand Savings:                          1,036                   kW/yr.

                Gas Savings:                                  0                          MCF/yr.

                Cost Savings:                             $11,200                 /yr.

                Implementation Cost:                $ 159,430               $

                Simple Payback:                            14.2                     Years

                Estimated Useful Life:                  25                        Years

 

ECRM No. 3 DESCRIPTION 

 

Installation of an Energy Management System (EMS) in each of the buildings receiving electric heat under ECRM No. 1 will be required for staging the electric heating to maximize the demand savings.

 

The EMS will be configured to monitor campus electrical demand and will limit the number of electric heaters operating so as to not set a peak demand above that which would normally be set without electric heat.

 

Refer to Appendix A, pg. A-4 for savings calculations labeled “Electric Heat with Rider 4 & EMS Control”.  The savings are the difference between the annual electrical cost calculated in this model and the annual cost calculated for electric heat without EMS control under ECRM No. 1 (Appendix A, pg. A-2 - “Electric Heat with Rider 4”).

 

ECRM No. 3 ASSUMPTIONS

 

The analysis of ECRM No. 3 uses the same procedure as that used for ECRM No. 1 except that the affect of the electric heat on the peak electrical demand, referred to in the calculations as “coincident factor”, is set to zero.  Therefore, the assumptions used to evaluate ECRM No. 1 are inherent to this analysis.

ECRM NO.:  4

 

ECRM NAME:  Replace 3-Way with 2-Way Valves

 

SUMMARY DATA (DEPENDENT)

 

                kWh Savings:                                248,000               kWh/Year

                Demand Savings:                          896                      kW/yr.

                Gas Savings:                                  0                          MCF/yr.

                Cost Savings:                             $15,222                  /yr.

                Implementation Cost:                $ 160,500                $

                Simple Payback:                            10.5                      Years

                Estimated Useful Life:                  25                         Years

 

ECRM No. 4 DESCRIPTION 

 

Replace the majority of the 114 existing 3-way valves with 2-way valves at building AHUs to reduce pumping energy at low load conditions.  Some existing 3-way valves will remain in the system to maintain minimum flow requirements.

 

Refer to Appendix A, pg. A-5 for savings calculations labeled “Electric Heat with Rider 4 & 2-way Valves”.  The savings are the difference between the annual electrical cost calculated in this model and the annual cost calculated for electric heat with 3-way valves under ECRM No. 1 (Appendix A, pg. A-2 - “Electric Heat with Rider 4”).

 

ECRM No.4 ASSUMPTIONS

 

SSA used TRACE energy analysis software to determine the campus load profile (Appendix F).  From this, SSA determined the number of hours/year at each 5% increment of total load.  The load data was then used to determine the chilled water flow required from the central plants based on 3-way valves and 2-way valves at the AHUs.

 

A hydraulic model of the campus chilled water distribution system was developed using KYPipe software.  The flow data derived from the TRACE analysis was then entered into the model to determine the pumping requirements at the various load conditions for 3-way and 2-way valves.  The input and output files for KYPipe are included in     Appendix H.  The pumping power for the 3-way valves was then compared with the 2-way valves to determine the net savings (See Appendix A, pg. A-8 & A-9).  Assumptions used to arrive at the pumping requirements for the two types of control valves are discussed below.

 

3-Way Valves

 

This model represents the existing conditions.  To determine the flow rates in the system, SSA assumed a chilled water differential temperature (DT) of 7 °F.  TAMU-K indicated that the typical system DT ranges between 6°F to 8°F.

 

Because 3-way valves create a constant volume/head system, the hydraulic model maintained a constant flow and head at each load increment.  The flow and head are reduced as chillers and their associated pumps are taken off line.  At 100%, the load requires four chillers to be run and at 80% load only three chillers are required.  Therefore, the required flow for four chillers, 8742 gpm was held constant for each increment that required four chillers (100% down to 85%).  The required flow for three chillers, 7431 gpm was held constant for each increment that required three chillers (80% down to 60%) and so on.

2-Way Valves

 

By replacing the existing 3-way valves with 2-way valves, the system differential temperatures can be raised by several degrees.  SSA assumed that the DT would be raised to 10 °F.  This is conservative based on the fact that most coils are selected for 12°F DT.  This increase in DT will significantly reduce the required flow and consequently reduce the head requirements of the primary pumps.

 

In addition, 2-way valves allow the flow to decrease as the load decreases.  Therefore, at each increment of total load, the corresponding required flow will decrease.  Although the head remains somewhat constant, by reducing the amount of flow, the pumping energy is reduced.

 

Demand Savings

 

It was assumed that the campus thermal profile parallels the electrical load profile.  Therefore, SSA estimated the monthly demand savings by determining the monthly thermal peak and used the demand savings that corresponds to the respective percentage of the total campus load.  For example, if the monthly campus thermal peak was 1900 tons (75%), the corresponding monthly demand savings was 41 kW.

ECRM NO.:  5

 

ECRM NAME:  Install VFDs on Primary Chilled Water Pumps

 

SUMMARY DATA (DEPENDENT)

 

                kWh Savings:                                15,171                 kWh/Year

                Demand Savings:                          12                        kW/yr.

                Gas Savings:                                  0                          MCF/yr.

                Cost Savings:                             $316                      /yr.

                Implementation Cost:                $ 85,600                 $

                Simple Payback:                            N/A                     Years

                Estimated Useful Life:                  25                        Years

 

ECRM No. 5 DESCRIPTION

 

The installation of VFDs on the primary chilled water pumps in the two central is an extension of ECRM No. 4.  VFDs cannot be installed unless the existing 3-way valves are replaced with 2-way valves.  The intent of this ECRM is to further reduce the pumping energy requirements of the system.

 

The hydraulic model created for the two way valves in ECRM No. 4 was modified to determine the pumping requirements for VFDs at the various loads.  The savings from the VFDs come from the turn down available between increments of chiller capacity, i.e., once the chilled water demand drops below the capacity that can be handled with one less chiller, a chiller and pump are taken off-line.  The analysis indicated that there would be little savings attributable to the VFDs, therefore, SSA does not recommend pursuing ECRM No. 5.

 

Refer to Appendix A, pg. A-6 for savings calculations labeled “Electric Heat with Rider 4 & VFDs”.  The savings are the difference between the annual electrical cost calculated in this model and the annual cost calculated for electric heat with 2-way valves under ECRM No. 4 (Appendix A, pg. A-5 - “Electric Heat with Rider 4& 2-way Valves”).

 

ECRM No. 5 ASSUMPTIONS

 

The assumptions are the same as ECRM No. 4 with one exception.  With 2-way valves, only the flow can be reduced as the load decreases.  The head requirements essentially remain constant.  With VFDs, the pump head requirements would decrease as well as the flow to further reduce the required pump energy.

 

ECRM NO.:  6

 

ECRM NAME:  Install Thermal Storage

 

SUMMARY DATA (DEPENDENT)

 

                kWh Savings:                                   0                        kWh/Year

                Demand Savings:                             9652                  kW/yr.

                Gas Savings:                                     0                        MCF/yr.

                Cost Savings:                             $    91,665               /yr.

                Implementation Cost:                $    856,000             $

                Simple Payback:                               N/A                   Years

                Estimated Useful Life:                     25                      Years

 

ECRM No. 6 DESCRIPTION

 

A thermal storage system adequate to provide a full shift will require approximately 14,000 ton hours of capacity.  This system will cost approximately $1,225,000.  The CP&L thermal storage incentive rebate will pay approximately $425,000 of this cost, leaving a net cost for the project of $800,000.

 

However, current CP&L rates do not encourage thermal storage.  The Select Time of Use (S-TOU) Rate is the rate used to evaluate ECRM 6.  At first look, it appears that the S-TOU rate encourages thermal energy storage by the fact that it has no demand component and that the energy charge (EC) during the off-peak hours is considerably less than the on-peak hours.  Further, the wider the on-peak window the customer selects, the lower the off-peak energy charge.  However, in addition to the energy charge there is a delivery charge (DC) which as stated in the rate is designed to achieve revenue neutrality with the customer’s standard rate schedule.  In other words, the delivery charge adds back into the bill the difference between the energy charge under S-TOU and the customer’s bill as would have been calculated under the customer’s previous rate for the previous year.  It appears that this rate would only offer savings to a customer that is expecting a large increase in electrical usage.

SSA also evaluated this ECRM under TAMU-K’s standard rate, Rate 45.  Refer to Appendix A, pg. A-7 for the

savings calculations labeled “Electric Heat with Rider 4 plus Thermal Storage”.  The savings are the difference between the annual electrical cost calculated in this model and the annual cost calculated for electric heat under ECRM No. 1 (Appendix A, pg. A-2 - “Electric Heat with Rider 4”).

 

This scenario seems to offer significant savings through load leveling, i.e., spreading electrical demand over 24 hours thereby lowering the campus peak demand.  This approach is not very realistic.  If TAMU-K were to lose their thermal storage system for some unforeseen reason, they could quite possibly set a high peak demand for that month.  In addition, Rider 4 has a ratchet that could possibly set the peak for the entire year.

 

SSA does not recommend the implementation of this ECRM.

 

ECRM No. 6 ASSUMPTIONS

 

Had CP&L’s rates been favorable, the thermal load profile developed with TRACE  along with TAMU-K’s electric profile would have provided the basis for calculating the savings and determining the size of the thermal energy storage tank.