USI BOILER EFFICIENCY PROGRAM 

A REPORT SUMMARIZING 

THE FINDINGS AND RECOMMENDATIONS 

OF AN EVALUATION OF BOILERS 

IN STATE OPERATED FACILITIES 

Prepared for 

The State Energy Office 

NC Department of Administration 

1830A Tillery Place 

Raleigh, NC 27604 

By

Dr. Herbert M. Eckerlin

Eric W. Soderberg 

Mechanical & Aerospace Engineering 

Industrial Extension Service 

P.O. Box 7910 

North Carolina State University 

Raleigh, NC 27695 

Telephone: (919) 515-5227 

 

September 15, 2003 (original) 

(this revision - 2/25/04) 
EXECUTIVE SUMMARY 

 

An analysis of 123 steam and hot water boilers has been conducted at the larger state 

operated facilities across North Carolina. The analysis included site visits to the 

facilities, interviews with boiler operators and maintenance personnel, and measurements 

of important variables for identifying energy saving opportunities and boiler efficiencies. 

The tests were conducted by NCSU as part of the Utility Savings Initiative (USI)

Program administered by the State Energy Office (SEO). These tests are a necessary first 

step in the development of a comprehensive program to improve boiler 

operation/efficiency at state facilities and to reduce their overall energy costs. Of the 123 

boilers tested to date, 78 are steam boilers installed in the 28 central heating plants 

located across the state. The remaining 45 smaller boilers (including 18 steam and 27 hot 

water boilers) are located in individual buildings. 

The boiler test data has been categorized into two parts. Part I includes the 78 larger 

boilers located in the central heating plants and Part II covers the 45 boilers located in 

individual buildings. An analysis shows that the Part I boilers in the central heating 

plants have an annual fuel bill of $23,666,407 (see Table 1). For these plants, the USI 

Boiler Program identified potential energy savings of $1,338,000 (or 5.65 percent of the 

total fuel usage) (see Table 2). Fuel use data on the smaller boilers (located in individual 

buildings) are not yet available. When they become available, these data will be included 

in the subject report. 

The major findings and resulting recommendations growing out of the USI Boiler 

Program are presented below: 

RECOMMENDATIONS RELATED TO STACK LOSS 

• Temperature gauges to measure the stack temperature are not in place on any of the 

45 boilers located in individual buildings. This measurement is essential for the 

proper monitoring of boiler operation and efficiency. 

RECOMMENDATION:Install flue gas temperature gauges after the last point of 

heat recovery on all boilers included in this study. 

• In 37 percent of the boilers tested, energy savings in the 2 to 5% range can be 

achieved by reducing the stack temperature.

RECOMMENDATION:Clean the heat transfer surfaces and/or repair the baffles to 

reduce the exit flue gas temperature.

• Sixty-two (62) percent of the 123 boilers have not had a burner tune-up in the last 12 

months. Forty-two (42) percent of the boilers in individual buildings have never been

tuned. Burner tune-ups can typically provide efficiency gains in the 1 to 5 percent 

range. 

RECOMMENDATION:Establish a state-wide program that requires annual burner 

tune-ups. 

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RECOMMENDATION RELATING BOILER SIZE TO LOAD 

• Many of the boilers in state facilities are oversized and have to operate at low firing 

rates (particularly in the summer) where they are generally less efficient. 

RECOMMENDATION:At these facilities, identify a boiler that can be tuned for 

low fire operation. 

 COMMENT: It should also be noted that radiation losses (as a percent) 

become quite large at lower firing rates. 

RECOMMENDATION RELATED TO CONDENSATE RETURN 

• In 39 percent (11 out of 28) of the central heating plants, condensate return is 50% or 

less. A 50% loss in condensate is equivalent to a 6 percent energy loss. 

RECOMMENDATION:Establish a program for the continuous evaluation and 

repair of condensate return systems. 

RECOMMENDATIONS RELATED TO FUEL USAGE 

• Fuel flow to individual boilers is not measured on seventy-three (73) percent of the 

boilers tested. For boilers in individual buildings, fuel flow is not measured on any of 

the 45 smaller boilers. 

RECOMMENDATION:Install fuel flowmeters on boilers larger than 50 HP. It is 

also recommended that plant personnel track their monthly 

energy use and report it to the SEO or NCSU. 

• Because of the recent increase in the price of natural gas, many state facilities have 

switched to oil firing. This switch has the potential to create maintenance problems in 

the future because of sulfur induced cold-end corrosion inherent in oil firing. As a 

result, state administrators should consider increasing their maintenance budgets to 

cover the higher maintenance costs (expected to show up in about two years). 

RECOMMENDATION:Increase maintenance budgets to cover the higher 

maintenance costs. 

• Facilities that only have the capability to fire natural gas are at risk to future price 

increases in natural gas. Most of the boilers located in individual buildings fall in this 

category. 

RECOMMENDATION: Establish dual fuel capability for these boilers (e.g., low 

sulfur oil or propane). If oil is selected as the second fuel, 

its use should be limited to reduce the potential for 

corrosion. 

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RECOMMENDATIONS RELATED TO EQUIPMT. & MAINT. 

• The lack of parts has become a serious problem in maintaining boilers in an 

operational condition. This is particularly true for burner and control system parts – 

even for systems of recent vintage (less than 10 years old). This problem appears to 

be an outgrowth of the state’s current "low bid process." Other factors will have to be 

included in the bidding process to insure that the state equipment purchases will have

replacement parts available for at least ten years. 

RECOMMENDATION:Establish a new bid process that considers system quality 

and guarantees the availability of parts for at least ten 

years. 

• The larger boilers in the central heating plants are better maintained than the smaller 

boilers located in the individual buildings. This can be attributed to the fact that the 

central plants typically have staff dedicated to their operation and maintenance. 

RECOMMENDATION:For smaller facilities where boilers are likely to be located 

in individual buildings, the administration should be 

encouraged to establish a maintenance team dedicated to 

the maintenance of the boilers in the individual buildings.

• Some boiler plants have experienced problems that have persisted for years without 

resolution (e.g., cavitation in boiler feed pumps, reduction in boiler capacity over 

time). 

RECOMMENDATION:Establish a technical assistance organization (perhaps at a 

state land-grant university) with the capability to research 

these problems and provide unbiased expert 

advice/assistance. 

POLITICAL AND CULTURAL FACTORS 

• At a more philosophical level, the poor condition of the boiler rooms across the state 

can be attributed to three factors: 

1. The lack of education and training among boiler staff in boiler operating and 

efficiency principles. 

2. The lack of funds to properly maintain the boilers and steam/hot water 

distribution equipment. 

3. And, perhaps most importantly, the lack of top-management support. In cases 

where top-management support exists, factors (1) and (2) are usually not an issue. 

_______________________________________________________________________ 

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IMPLEMENTING RECOMMENDATIONS – SOME SUGGESTIONS 

In light of the above analysis, the issue before us is: “How should the State of North 

Carolina move forward in the development of a comprehensive program to improve

boiler operation and efficiency and reduce boiler fuel usage/cost?” As a first step, we 

would offer the following suggestions: 

1. Establish a policy requiring all boiler operators, maintenance personnel, and 

boiler plant supervisors to regularly attend “Boiler Efficiency Workshops” offered 

by NCSU under sponsorship of the State Energy Office. State personnel would 

be able to attend at no charge. 

2. Establish a Technical Resource Center for Plant Operations at one of the state 

supported land-grant universities to provide advice, guidance and technical 

assistance to boiler operators and supervisory personnel in the implementation of 

the above recommendations. Without the burden of having to sell a particular 

service or product, this Center would be able to provide unbiased advice on a 

wide variety of boiler issues, as well as assisting on bid evaluation, project 

oversight, and performance testing related to guarantees. 

3. Establish a technical assistance program for the resolution of irritating problems 

that have tended to persist for years. Examples of these types of problems are 

"feedwater pump cavitation" and "boilers unable to attain full load operation." 

These types of problems may be caused by a variety of factors and often cannot 

be resolved in a telephone call or a single plant visit. Allowing these problems to 

continue unattended is a disservice to the state and its citizens. 

4. Develop guidelines for assisting state agencies in establishing realistic 

maintenance budgets for their boilers and other mechanical equipment. 

5. Develop guidelines for assisting state agencies in determining when it is to their 

advantage to switch fuels (e.g., from natural gas to oil and vice versa). 

6. Distribute to all participating State Agencies copies of the three master summary 

tables (to be provided under separate cover) entitled: 

• A SUMMARY OF PLANT FEATURES 

• A SUMMARY OF BOILER FEATURES 

• A SUMMARY OF RECOMMENDATIONS FOR EACH BOILER 

These tables provide detailed information on the characteristics and operation of 

each boiler and plant, as well as related recommendations. These tables will 

enable plant personnel to compare their operation with others, will encourage 

communication and sharing of information among plant operating personnel 

across the state, and will serve to motivate and spur them to action. This process 
could be further enhanced through boiler workshops (conducted by the above 

proposed Center) that highlight the successful implementation of ECOs and 

demonstrates for others how it is done. 

7. Introduce a program for educating our legislators on the financial and operational 

costs associated with continual postponement of much needed maintenance 

projects. 

TABLE 1. ANNUAL FUEL COST FOR CENTRAL HEAT PLANTS

 

FACILITY ANNUAL FUEL COST 

 ($/yr) 

 

UNC-CH $5,920,000

Appalachian State Univ. $2,250,000 

Eastern Carolina Univ. (main campus) $1,830,000 

DOA - Central Heating Plant $1,714,035 

NCSU – Yarbrough $1,306,711 

UNC – Greensboro $1,200,000 

Cherry Hospital $1,153,500 

UNC – Charlotte $1,093,600 

A&T University $1,083,000 

NCSU – Cates $798,070 

Umstead Hospital $670,000 

Dorothea Dix $571,607 

Broughton Hospital $510,000 

McCain Corr. Inst. $500,000 

Winston-Salem State Univ. $404,000 

Central Prison $400,000 

Caswell Center $400,000 

Murdoch Center $286,114 

Women's Prison $275,000 

NC Central University $273,000 

NCSU - Vet Sch $228,000 

NC School of Math & Science $221,870 

Western Carolina Sch. For the Deaf $171,000 

Black Mt. Center $164,000 

Western Youth Institute $134,000

NC Special Care $87,200 

Gov. Morehead School for the Blind $21,700 

Western Carolina Univ. 

Eastern Carolina Univ. (med. school) 

 

Total $23,666,407

 

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TABLE 2. ENERGY AND COST SAVING RECOMMENDATIONS FOR BOILERS IN CENTRAL HEATING PLA

Annual 

Fuel Cost 

Facility ($/yr) Recommendations 

UNC-CH $5,920,000 Reduce Operating Pressure on New Boiler No. 8 Appalachian State Univ. $2,250,000 Continue to Replace Old Condensate Return Lines to Increase Return $

Reduce Boiler Operating Pressure $Reduce Maintenance on John English Boilers $Watch for Economizer Plugging on Oil Firing 

Eastern Carolina Univ. (main campus) $1,830,000 Continue Improving Condensate Return System DOA - Central Heating Plant $1,714,035 Repair Condensate Return System to Improve Return. $

Burner Tuneup on Boilers No. 2, 3, & 4 to Adjust O2 and Reduce CO. (O2 on

Boiler No. 4 is Dangerously Low). $

Correct High Stack Temperature (600 F) on Boiler No. 4. $

Improve Steam Trap Maintenance Program (Plumbing Shop) $

Open Side Damper on Air Inlet Duct at Roof to Draw In Warm Boiler Room Air for 

Combustion. 

Reduce Bottom Blowdown to 3 – 5 seconds Per Blow. 

Repair In-Situ O2 Readouts and Controls (as part of tuneup). Improves safety. 

UNC - Greensboro $1,200,000 Repair O2 Trim (3 boilers) $

Modify One Boiler for Low Load Operation Repair Soot Blowers on All Boilers – Particularly for Oil Firing Repair Flooding Problem in Steam Tunnels 

(1) Cost is for initial setup. Thereafter, annual tuning would be approximately $1,000/boiler.(2) An analysis of the problem must first be conducted. The solution may be relatively inexpensive, yielding a good payback. However, the exac

first be identified. 

(3) Total cost to repair O2 Trim is $12,000 (for three boilers) plus travel expenses. (5) Problems with condensate return systems are common in state facilities. The cost of repair varies widely depending on the size of the campus 

problems. An evaluation of the system is required before a cost estimate can be made. 

(3)

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Annual 

Fuel Cost S

Facility ($/yr) Recommendations 

NCSU – Yarbrough $1,306,711Insulate Oil Storage Tanks – insulation removed because of tank rust problem. $

Repair Condensate Return System to Increase Return – now being corrected. $

Improve Steam Trap Maintenance Program – part of steam distribution/condensate return system now under repair. $

Repair Cold-End Corrosion on all Tubular Air Heaters – underway. $Burner Tuneup to Reduce O2 . $Repair/Replace O2 Trim System – required for tuneup to work effectively. $

Consider Switching to Lower Sulfur No. 2 Fuel Oil to Reduce Cold-End Corrosion and Reduce Future Maintenance Costs. 

Cherry Hospital $1,153,500

Boilers are Oversized; Purchase Smaller Boiler for Low Load Operation (Existing 2 boilers are

rated at 66,000 lb/hr each) $

 Improve Hot Water Distribution System - must be evaluated.  Reduce Bottom Blowdown Time  Evaluate “Cascades” Hot Water Circulation System (by NCSU)

UNC - Charlotte $1,093,600Repair Condensate Return System to Increase Return – partially underway, very important) $

Burner Tuneup on Boilers No. 3 & 4 $

NC A&T University $1,083,000Combined Effect of Burner Tuneup and Reducing FG Temp. on all Boilers $

Repair Condensate Return System to Increase Return – very important. $Improve Steam Trap Maintenance Program $Repair Flooding Problem in Steam Tunnels 

(1) Cost is for initial setup. Thereafter, annual tuning would be approximately $1,000/boiler.(4) Cause and effect of problem must be evaluated before this recommendation can be considered for implementation. (5) Problems with condensate return systems are common in state facilities. The cost of repair varies widely depending on the size of the campus 

problems. An evaluation of the system is required before a cost estimate can be made. 

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Annual 

Fuel Cost 

Facility ($/yr) Recommendations 

NCSU - Cates Ave. $798,070

Repair Condensate Return System to Increase Return – campus-wide problem now beingaddressed. $Consider Switching to Lower Sulfur No. 2 Fuel Oil to Reduce Cold-End Corrosion and Resulting Maintenance – important preventive maintenance step. $

Tune Boiler for Lower Load Operation (If Boiler Continues to Be the Summer Boiler) $

Improve Steam Trap Maintenance Program - part of steam distribution/condensate return system now under repair. $

Umstead Hospital $670,000Burner Tuneup to Reduce O2 (3 boilers) $

Clean Heat Transfer Surfaces to Reduce Stack Temp. Institute Steam Trap Maintenance Program Reduce Bottom Blowdown Time Repair Blowdown Heat Recovery 

Dorothea Dix $571,607Repair Condensate Return System to Increase Return 

Burner Tuneup - Reduce O2 (4 Boilers) Reduce Soot Deposits on Boiler No. 3 (some analysis is required to identify cause of problem). Reduce Bottom Blowdown Time 

Repair Economizer on Boiler No. 1: Also Repair Soot Blowers (some analysis is required to identify cause of problem). 

Broughton Hospital $510,000Correct High Stack Temperature 

Repair Condensate Return System and Increase Return - very important 

Burner Tuneup on Boiler No. 2 & 4 – Reduce O2 and CO Reduce Bottom Blowdown Time 

(1) Cost is for initial setup. Thereafter, annual tuning would be about $1,000/boiler. (2) An analysis of the problem must first be conducted. The solution may be relatively inexpensive, yielding a good payback. How

the problem must first be identified.

(5) Problems with condensate return systems are common in state facilities. The cost of repair varies widely depending on the size 

nature of the problems. An evaluation of the system is required before a cost estimate can be given. 

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Annual 

Fuel Cost 

Facility ($/yr) Recommendations 

McCain Corr. Inst. $500,000Repair Condensate Return System and Increase Return 

Reduce Stack Temperature (the two boilers are over 50 years old and may not be worth fixing). Burner Tuneups to Reduce O2 and CO - (because of boiler age, this may not be practical). 

Initiate Steam Trap Maintenance Program 

Purchase Smaller Boiler for Summer Operation Refurbish Continuous Blowdown System Reduce Duration of Bottom Blowdown Replace Boilers 

Winston-SalemState Univ. $404,000Repair Condensate Return System to Improve Return 

Improve Steam Trap Maintenance Program 

Add Soot Blowers to Boilers No. 1 and 3 if use of No. 2 Fuel Oil Increases 

Burner Tuneup on Boiler No. 2 – Adjust O2 and Reduce CO Burner Tuneup on Boiler No. 3 to Reduce O2 and Stabilize Combustion Correct High Stack Temp. on Boiler No. 3 

Central Prison $400,000Burner Tuneup – Reduce O2 

Reduce Stack Temp. Repair Condensate Return System and Increase Return 

Initiate Steam Trap Maintenance Program 

Reduce Bottom Blowdown Time Designate one boiler for low-load operation 

(2) An analysis of the problem must first be conducted. The solution may be relatively inexpensive, yielding a good payback. How

the problem must first be identified.

(5) Problems with condensate return systems are common in state facilities. The cost of repair varies widely depending on the size 

nature of the problems. An evaluation of the system is required before a cost estimate can be given. 

(6) These burners are quite old and may have to be replaced. 

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Annual 

Fuel Cost 

Facility ($/yr) Recommendations 

Murdoch Center $286,114Burner Tuneup for All 3 Units (3 boilers) 

Reduce Stack Temp. on Boiler No. 2 & 3 Tune One Boiler for Low Load Summer Operation 

Re-establish a Good Water Treatment Program 

Women's Prison $275,000Correct High Stack Temp. (3 boilers) 

Burner Tuneup – Reduce O2 (3 boilers) Increase Condensate Return Designate and Tune One Boiler for Summer Operation 

Initiate Steam Trap Maintenance Program 

Reduce Bottom Blowdown Time 

NC Central University $273,000Reduce Exit Flue Gas Temperature On Boiler No. 1. 

Conduct Burner Tuneup on Boiler No. 2 

Or Discontinue Alternating Boilers No. 1 & 2 in Winter.

Conduct Burner Tuneup on Boiler No. 3 Repair Campus Condensate Return System 

Reduce Bottom Blowdown Time 

Install Makeup Water Flowmeter Institute Steam Trap Maintenance Program 

NCSU - Vet Sch $228,000Burner Tuneup - Reduce O2 (on existing boiler) 

Measure and Increase Condensate Return Establish a Steam Trap Maintenance Program Designate and Tune One Boiler for Low-Load Summer Operation (perhaps new boiler) 

(2) An analysis of the problem must first be conducted. The solution may be relatively inexpensive, yielding a good payback. How

the problem must first be identified.

(5) Problems with condensate return systems are common in state facilities. The cost of repair varies widely depending on the size 

nature of the problems. An evaluation of the system is required before a cost estimate can be given. 

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Annual 

Fuel Cost 

Facility ($/yr) Recommendations 

NC School of Math & Science $221,870Repair Condensate Return System to Improve Return 

Burner Tuneup to Reduce O2 and CO (New burner controls were installed in summer of 2002). Establish Steam Trap Maintenance Program Check Effectiveness of Oxygen Removal from Feedwater – Minimize Oxygen Pitting 

Caswell Center $400,000Correct 800 F Stack Temp. on Boilers No. 2 & 3 

 and Repair Economizer Problem on Boiler No. 2. Increase Condensate Return Reduce Bottom Blowdown Time Burner Tuneup on Boiler No. 1 to Reduce O2 

Black Mt. Center $164,000Burner Tuneup – Improve O2 and Reduce CO 

Replace Burner on Boiler 3. Work completed in 2003. Cost = $95k. Savings projected at $143k. 

Initiate Steam Trap Maintenance Program Boilers are Oversized; Designate One Boiler for Low-Load Operation 

Repair Flooding Problem in Steam Tunnels Correct Boiler Feed Pump Cavitation Problem; Allow Deaerator to Operate Above 212°F. Install makeup water flowmeter to get a more accurate Measure of Condensate Return Clarify Rationale for Low Nox Burner on Boiler No. 3. 

Western Carolina Sch. For the Deaf $171,000Establish a Steam Trap Maintenance Program 

Burner Tuneup to Reduce O2 on Boiler No. 3 

Boiler No.1 (800hp) is greatly oversized. Reduce Radiation Loss by not operating 800 hp Boiler. Consider selling it to larger facility and use the proceeds to purchase a smaller boiler. 

Avoid Low-Load Operation on Boiler No. 3 

(2) An analysis of the problem must first be conducted. The solution may be relatively inexpensive, yielding a good payback. How

the problem must first be identified.

(4) Cause and effect of problem must be evaluated before this recommendation can be considered for implementation. (5) Problems with condensate return systems are common in state facilities. The cost of repair varies widely depending on the size 

nature of the problems. An evaluation of the system is required before a cost estimate can be given. 

(7) The new controls were installed one year before the survey was conducted. Project cost was $108,497, with a projected savings 

annual fuel bill. After one year of operation, fuel usage actually increased by 13.2%. Further study is recommended.

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Annual 

Fuel Cost 

Facility ($/yr) Recommendations 

Western Youth Institute $134,000Convert Webster Burner to Dual-Fuel Firing (having dual-fuel capability is important) 

Repair Boiler Feed Pump Controls to Stop Continuous Pump Operation Repair Water Level Float in Deaerator and Reduce the use of Sodium Sulfite Solve Feedwater Pump Cavitation Problem – Reduce Maintenance Repair Multiport Relief Valve on Deaerator 

NC Special Care $87,200Repair Feedwater Pump Cavitation Problem and Operate Deaerator Properly (Above 212

Install Makeup Water Meter to determine Condensate Return Burner Tuneup on Boiler No. 2 to Reduce O2 Boiler Tuneup on Boiler No. 1 to Reduce O2 at High Fire 

Gov. Morehead School for the Blind $21,700Burner Tuneup - Reduce CO & O2 

Initiate Steam Trap Maintenance Program Designate 1 Boiler for Low Load Operation Reduce Boiler Operating Pressure 

Western Carolina Univ. Eastern Carolina Univ. (med. school) 

Total $23,666,407 

(2) An analysis of the problem must first be conducted. The solution may be relatively inexpensive, yielding a good payback. How

the problem must first be identified.

(8) Final cost will depend on if a new fuel train is required. Total cost estimate is $20,000 to $25,000. 

(9) A new bypass orifice may solve the problem.(10) Problem has been solved with a new bypass orifice. 

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