Single Duct Systems

The majority of all-air HVAC systems employ a single network of supply air ducts which provide a continuous supply of either warmed or cooled air to the occupied areas of the building. Single Zone The single duct, single-zone system is the simplest of the all-air HVAC systems. It is one of the most energy-efficient systems as well as one of the least expensive to install. It uses a minimum of distribution energy,* since equipment is typically located within or immediately adjacent to the area...

Jz1

Fig. 14.7 Inverted bucket steam trap. (Courtesy of Armstrong Machine Works) Fig. 14.7 Inverted bucket steam trap. (Courtesy of Armstrong Machine Works) Second, the design of the trap is self-cleaning dirt is scoured from the bottom of the trap automatically as a result of the trap design. Thus there is less likelihood that the trap will become plugged up with dirt, although a large dirt particle could still keep the bucket lifted up or the valve jammed open. Both of these problems can be...

1122 Nameplate Glossary

HP The number of, or fractional part of a horsepower, the motor will produce at rated speed. RPM An indication of the approximate speed that the motor will run when it is putting out full rated output torque or horsepower is called full load speed. VOLTS Voltage at which the motor may be operated. Generally, this will be 115 Volts, 230 Volts, 115 230 V, or 220 440 V. AMPS The amount of current the motor can be expected to draw under full load (torque) conditions is called full load amps. It is...

Economic Thickness

INSULATION THICKNESS, INCHES Fig. 15.5 Economic thickness of insulation (ETI) concept. now NAIMA, North American Insulation Manufacturers Association). The manual was entitled How to Determine Economic Thickness of Insulation and employed a number of nomographs and charts for manually performing the calculations. Since that time, the use of computers has greatly changed the method of ETI calculations. In 1973, TIMA released several programs to aid the design engineer in selecting the proper...

2131 Supply

Natural gas is a product coming from the earth. As discussed previously, the major component of natural gas is the chemical compound methane, CH4. Methane is the product formed when organic matter like trees and foliage decays without sufficient oxygen available to completely transform the carbon in these materials to carbon dioxide. Theory is natural gas deep in the ground is a product of decaying material from past millions of years of the earth's history. Chemical elements available as the...

723 The Cogeneration Design Process

The following evaluation steps are suggested to carry out cogeneration system design. 1. Develop the profile of the various process steam (heat) demands at the appropriate steam pressures Figure 7.13 Proton Exchange Membrane (PEM ) fuel cells use platinum catalysts to promote the flow of anions (positive ions) through the membrane, thus creating a direct current (DC). An inverter can be used to convert DC to AC. Figure 7.13 Proton Exchange Membrane (PEM ) fuel cells use platinum catalysts to...

Remarks

Just in Time Scheduled Filter Changes (predictive maintenance) Air mover efficiency is lost if f Iter replacement is postponed. Filter costs are higher than necessary when filters are changed too early. Identify filter change-out points. For constant volume air systems this is a straight forward application of a filter differential pressure (dP) switch, set to announce the need for service VAV systems will require special scheduled off-hour events to open the VAV boxes and speed up the fan to a...

Method 2 Rpm Ratio Method

Step 1 measure the existing driven (fan) pulley rpm with an accurate tachometer instrument. Step 2 divide the payback drive rated rpm (1600-1700)* by the measured (fan) rpm. *See applicable model data sheet for max rated output given horsepower. (Payback Max Rated Rpm) (Existing Driven (Fan) Pulley Rpm) (Rpm Ratio) Step 3 multiply the listed sheaves diameter of the appropriate payback drive by the calculated rpm ratio to determine the ideal new driven (fan) sheaves diameter. (Payback Listed...

1343Group Relamping

Most companies replace lamps when someone notices a lamp is burned out. In a high rise building, this could become a full-time job, running from floor to floor, office to office, disrupting work to open a fixture and replace a lamp. However, in certain cases, it is less costly to group re-lamp on a pre-determined date. Group relamping can Figure 13.5 Lamp lumen depreciation (LLD). Figure 13.5 Lamp lumen depreciation (LLD). be cost-effective due to economies of scale. Replacing all lamps at one...

Building Load Coefficient Estimate

As discussed elsewhere in Section 9.9, one of the reasons a building might be classified as thermally heavy would be the presence of significant internal heat gains, such as lighting, equipment and people. To the extent these gains occur in the perimeter of the building, they will tend to offset the heat loss predicted using the tools described previously in this chapter. The greater the internal heat, relative to the overall building temperature dependence (BLC), the lower the outside...

Info

A second principle of energy management is to control energy functions as a product cost, not as a part of manufacturing or general overhead. It is surprising how many companies still lump all energy costs into one general or manufacturing overhead account without identifying those products with the highest energy function cost. In most cases, energy functions must become part of the standard cost system so that each function can be assessed as to its specific impact on the product cost. The...

References

Claridge D.E., Turner, W.D., Liu, M., Deng, S., Wei, G., Culp, C., Chen, H., and Cho, S. 2002. Is Commissioning Once Enough Solutions for Energy Security and Facility Management Challenges Proceedings of the 25th WEEC, Atlanta, GA, October 19-11, 2002, pp. 29-36. 2. Haberl, J., Lynn, B., Underwood, D., Reasoner, J., Rury, K. 2003. Development an M& V Plan and Baseline for the Ft. Hood ESPC Project, ASHRAE Seminar Presentation, (June). 3. C. Culp, K.Q. Hart, B. Turner, S. Berry-Lewis, 2003....

1322 Lighting Quality

Lighting quality can have a dramatic influence on the attitude and performance of occupants. In fact, different moods can be created by a lighting system. Consider the behavior of people when they eat in different restaurants. If the restaurant is a fast-food restaurant, the space is usually illuminated by bright white lights, with a significant amount of glare from shiny tables. Occupants rarely spend much time there partly because the space creates an uncomfortable mood and the atmosphere is...

29

Many pounds of 50-psig steam does this unit require per hour The density of air at temperatures of several hundred degrees or below is about 0.075 lb ft3. The number of pounds of air passing through the dryer is then 3000 ft3 min x 60 min hr x 0.075 lb ft3 13,500 lb hr Suppose that the air enters the steam-coil unit at 70 F. Its temperature will then be raised by 200 - 70 130 F. From Table 6.7 the specific heat of air is 0.24 Btu lb F. The energy required to provide this temperature rise is,...

Savings Potential

Energy consumption for the three alternatives is estimated by an outdoor temperature bin method. The calculations are performed in a spreadsheet using 5 F bin data because this is a form in which data are readily available (TM 5-785). The main assumption underlying this type of analysis is that the facility is thermally light. This implies that the heating and cooling loads on the building are proportional to the outside air temperature. A thermally heavy facility would be a building in which...

842 Gasto Gas Heat Exchangers Recuperators

Recuperators are used in recovering waste heat to be used for heating gases in the medium- to high-temperature range. Some typical applications are soaking ovens, annealing ovens, melting furnaces, reheat furnaces, afterburners, incinerators, and radiant-heat burners. The simplest configuration for a heat exchanger is the metallic radiation recuperator, which consists of two concentric lengths of metal tubing, as shown in Figure 8.18. This is most often used to extract waste heat from the...

1354 High Intensity Discharge HID Systems

Metal Halide lamps have become more popular due to technological advancements and consumer preference for white light. Technologically, the pulsestart metal halide systems are a significant improvement in efficiency and performance. Like most electronic ballasts, these operate at high frequency, provide a quicker re-strike time (3-5 minutes) versus standard metal halide systems (6-10 minutes). The pulse-start systems maintain CRI and lumen output better over time. Low-wattage metal halide (<...

Appendix Nomenclature

Ac Equipment ownership, lease or rental cost ( kW year) ADC Annual Demand Cost ( year) AEC Annual Energy Cost ( year) AW Annual Worth ( year) Cd Electric demand unit cost ( kW month) Ce Electric energy unit cost ( kWh) D Electric demand or load (kW) D1 Lower bound of a facility's electric demand or minimum load (kW) Du Upper bound of a facility's electric demand or maximum load (kW) EBC Electric bill cost for a facility with PSG, ( year) f(D) Frequency of occurrence of a demand, (unit less)...

33 Basic Components Of An Energy Audit

An initial summary of the basic steps involved in conducting a successful energy audit is provided here, and these steps are explained more fully in the sections that follow. This audit description primarily addresses the steps in an industrial or large-scale commercial audit, and not all of the procedures described in this section are required for every type of audit. The audit process starts by collecting information about a facility's operation and about its past record of utility bills....

12a40 Operating Sequence Logic

12.A4.1 AHU START STOP Install Enable Disable of Air Handling Units as follows a. Whenever School Hours 1 and Snow Day 0 all Air Handling Units shall be Enabled on to start the supply air fans. b. Whenever Regular Office Hours 1 or Vacation Office Hours 1 AHU-9 shall be Enabled on. c. Whenever an individual area activity is scheduled on (i.e. a certain XXX Activity 1) and Snow Day 0 the air handling unit serving that area shall be Enabled on. d. Whenever School Hours 0 and the activity flag for...

Case Study

Suppose PizzaCo (the host facility) needs a new chilled water system for a specific process in its manufacturing plant. The installed cost of the new system is 2.5 million. The expected equipment life is 15 years, however the process will only be needed for 5 years, after which the chilled water system will be sold at an estimated market value of 1,200,000 (book value at year five 669,375). The chilled water system should save PizzaCo about 1 million year in energy savings. PizzaCo's tax rate...

26600

The interpolation proceeds by setting up ratios and solving for the unknown value, (FI P,13 ,7), as follows change between rows 2 & 1 of left column change between rows 3 & 1 of left column 0.13 -0.12 _ (Fl P,13 ,7) - 2.2107 0.15 - 0.12 2.6600 - 2.2107 0.01 (FIP,13 ,7) - 2.2107 0.03 _ 0.4493 The interpolated value for (FIP,13 ,7), 2.3605, differs from the exact value, 2.3526, by 0.0079. This would imply a 7.90 difference in present worth for every thousand dollars of return at t_7. The...

2847 Summary of Ground Loop Design Software

Because of the diversity in loads in multi-zone buildings, the design of the ground-coupling heat exchanger (the ground loop) must be based on peak block load rather than the installed capacity. This is of paramount importance because ground coupling is usually a major portion of the total ground-source heat pump system cost, and over-sizing will render a project economically unattractive. In the residential sector, many systems have been designed using rules-of-thumb and local experience, but...

2712History of MV

27.1.2.1 History of Building Energy Measurement. The history of the measurement of building energy use can be traced back to the 19th century for electricity, and earlier for fuels such as coal and wood, which were used to heat buildings.4,5,6,7 By the 1890s, although electricity was common in many new commercial build ings, its use was primarily for incandescent lighting and, to a lesser extent, for the electric motors associated with ventilating buildings since most of the work in office...

213 Natural Gas As A Fuel

Why has natural gas grown in popularity What makes it a fuel of choice in so many industries as the new millennium begins What shortcomings does it have Figure 21.4 shows the change in basic fuels mix used in the U.S. in 1985 and 1999. Nuclear, which started in 1960, enjoyed a period of rapid growth. The high costs for all the safety engineered into the plants had made it an uneconomical system towards the end of the century. There are no nuclear plants scheduled for construction. Even some of...

Epact1992

The National Energy Policy Act of 1992 (EPACT) was designed to dramatically reduce energy consumption via more competitive electricity generation and more efficient buildings, lights and motors. Because lighting is common in nearly all buildings, it is a primary focus of EPACT. The 1992 legislation bans the production of lamps that have low efficacy or CRI. Table 13.17 indicates which lamps are banned and a few options for replacing the banned systems. From left to right, the table shows...

Lamp Lumen Depreciation Factor Lld A

Factor that represents the reduction of lumen output over time. The factor is commonly used as a multiplier to the initial lumen rating in illuminance calculations, which compensates for the lumen depreciation. The LLD factor is a dimensionless value between 0 and 1. LAY-IN-TROFFER A fluorescent fixture usually a 2' x 4' fixture that sets or lays into a specific ceiling grid. LED Abbreviation for light emitting diode. An illumination technology used for exit signs. Consumes low wattage and has...

8113 Runaround Systems

Whenever it is necessary to ensure isolation of heating and heated systems, or when it becomes advantageous to use an intermediate transfer medium because of the long distances between the two systems, a run-around heat recovery system is used. Figure 8.5 shows the schematic of a runaround system which recovers heat from the exhaust stream from the heating and ventilating system of a building. The circulating medium is a water-glycol mixture selected for its low freezing point. In winter the...

Peak Shaving Optimization Model and Case Study

While DG applications for continuous power generation (with no heat recovery) are rarely economically feasible, DG for peak shaving, in conjunction with back-up or emergency power generation, is generally an attractive business proposition. See Appendix A at the end of this chapter for a detailed case study which shows there is generally a good business case for peak shaving using diesel or gas fired generators. Such case study illustrates an optimization model to estimate the optimal peak...

2842 Other benefits

The primary benefit of ground-source heat pumps is the increase in operating efficiency, which translates to a reduction in heating and cooling costs, but there are additional advantages. One notable benefit is that ground-source heat pumps, although electrically driven, are classified as a renewable-energy technology. The justification for this classification is that the ground acts as an effective collector of solar energy. The renewable-energy classification can affect federal goals and...

Technology Description

Three technologies are compared in this example. The conventional technology is a rooftop air-conditioning system with integral natural gas furnace heaters. For this example, the capacity and input power are based on a commercially available rooftop unit with a rated heating capacity of 270 kBtu h (79.2 kW) and a rated cooling capacity of 162 kBtu h (47.5 kW) at ARI conditions. The equipment selected has a cooling efficiency of 8.2 EER and 10.1 IPLV11 at ARI conditions. The heating efficiency...

931 Using Parallel Path Correction Factors

Fortunately, most commercial construction consists of a limited number of metal stud assembly combinations, so the results of laboratory hot box tests of typical wall sections can be utilized to estimate the U-factors of walls with metal studs. ASHRAE Standard 90.1 recommends the following equation be used to calculate the equivalent resistance of the insulation layer installed between metal studs Table 9.2 Parallel path correction factors. Rt the total resistance of the envelope assembly R the...

631 Determining Steam Requirements

Several approaches can be used to determine process steam requirements. In order of increasing reliability, they include the use of steam consumption tables for typical equipment, detailed system energy balances, and direct measurement of steam and or condensate flows. The choice of which method is to be used depends on how critical the steam-using process is to the plant's overall energy consumption and how the data are to be used. For applications in which a high degree of accuracy is not...

Notes

Hot water 250 is available at 10 times the flow of steam 2Heat rate is the fuel heat input (Btu higher heating value) to the cycle per kWh of electrical output at design (full load) and ISO conditions (60 F ambient temperature and sea level operation) 3The electrical generation efficiency in percent of a prime mover can be determined by the formula Efficiency (3413 Heat Rate)100 Sources Adapted from Limaye (1985) and Manufacturers Data. Figure 7.5 Various multi-stage steam turbine systems....

Kti Civil Engineering

Baffle 397 ballast 360, 397 cycling 397 efficiency factor 397 factor 360, 397 bare-surface heat loss 461 base 222 before tax cash flows (BTCF) 44 Betz coefficient 485 bin 775, 777 method 246, 768 blower door attachment 25 boiler 338, 402, 722, 748 economizer 216 efficiency 128, 414 maintenance 413 measurements 722 optimization 320 boiling point 126 BOMA 797 bonds 655 borehole 766 bottoming cycle 157 Bourdon gauge 428 British thermal unit (Btu) 126 building automation system 616 building balance...

And Capacitance

The three types of electric circuit elements having distinct characteristics are resistance, inductance, and capacitance. This brief review will focus on the characteristics of these circuit elements in ac circuits to support later discussions on circuit impedance and power-factor-improvement principles. Resistance R in an ac circuit is the name given to circuit elements that consume real power in the form of heat, light. mechanical work, and so on. Resistance is a physical property of the wire...

1362 HVAC Effects

Nearly all energy consumed by lighting systems is converted to light, heat and noise, which dissipate into the building. Therefore, if the amount of energy consumed by a lighting system is reduced, the amount of heat energy going into the building will also be reduced, and less air-conditioning will be needed. Consequently, the amount of winter-time heating may be increased to compensate for a lighting system that dissipates less heat. Because most offices use air-conditioning for more months...

34 Specialized Audit Tools

Smoke is useful in determining airflow characteristics in buildings, air distribution systems, exhaust hoods and systems, cooling towers, and air intakes. There are several ways to produce smoke. Ideally, the smoke should be neutrally buoyant with the air mass around it so that no motion will be detected unless a force is applied. Cigarette and incense stick smoke, although inexpensive, do not meet this requirement. Smoke generators using titanium tetrachloride (TiC ) provide an inexpensive and...

611 Components of Steam and Condensate Systems

Figure 6.1 shows a schematic of a typical steam system in an industrial plant. The boiler, or steam generator, produces steam at the highest pressure (and therefore the highest temperature) required by the various processes. This steam is carried from the boiler house through large steam mains to the process equipment area. Here, transfer lines distribute the steam to each piece of equipment. If some processes require lower temperatures, the steam may be throttled to lower pressure through a...

634 Computing the Dollar Value of Steam

In analyzing energy conservation measures for steam systems, it is important to establish a steam value in dollars per pound this value will depend on the steam pressure, the boiler efficiency, and the price of fuel. Steam may be valued from two points of view. The more common approach, termed the enthalpy method, takes into account only the heating capability of the steam, and is most appropriate when steam is used primarily for process heating. The enthalpy method can be illustrated with an...

1353 Compact Fluorescent Lamps

Improvements to CFL technologies have been occurring every year since they became commercially available. Products available today provide higher efficacies as well as instant starting, reduced lamp flicker, quiet operation, smaller size and lighter weight. Dimmable CFLs are now available, and it can be expected that their performance will increase with time. The 2700K color (incandescent appearance) has been replaced by the 3000K for commercial applications. Pre-heat models start by blinking...

24

Where n represents the number of hours in the period for which the Degree Days are being reported, and Treference is a reference temperature at which no heating is assumed to occur. Typically, a reference temperature of 65 F is used. Units of degree hours can be obtained by multiplying the results of any Degree-Day tabulation by 24. Figure 9.23 shows the monthly natural gas consumption of a metropolitan newspaper building overlaid on a plot of local heating Degree Days. Because of the clear...

Q mCdT p VC dT

Where m mass of storage material, lbm p density of storage material, lb ft3 V volume of storage material, ft3 C specific heat of storage material, Btu lbm R T temperature in absolute degrees, R The specific heat for solids is a function of temperature which can usually be expressed in the form C0 C0 1 + a (T - Tq) (8.4) where C0 specific heat at temperature T0 a temperature coefficient of specific heat It is seen from equation 8.3 that storage materials should have the properties of high...

Night Setback

The principle of night set-back is to reduce the amount of conditioning provided at night by allowing the interior temperature to drift naturally to a marginal temperature during the night and then to recondition it to normal conditions in the morning. With the possible exception of electric heat pumps, night set-back will always save energy. The energy saved can be computed from the equation surface area of perimeter envelope, ft2 effective U-value of thermal envelope, Btu hr ft2 F ventilation...

Performance And Efficiency Terminology

There are many terms used in the heating, air-conditioning, and refrigeration industry that convey performance and efficiency. Many of these terms are synonymous, others are not. When comparing various systems, it is important to understand what the assorted terms are, how they are determined, and their relationship. The following provides a brief description of many (but not all) of the terms used to convey efficiency. Use of the terms is also summarized in Table 28.A.1. Annual Fuel...

Ai11 Ai12 Ai13 Ai14 Ai15 Ai16 Ai17 Ai18 Ai19 Ai20 Ai21 Ai22

Rm sensor AHU-1 Rm sensor AHU-1 Rm sensor AHU-2 Rm sensor AHU-2 Hot deck sensor AHU-2 Cold deck sensor AHU-2 Mixed air sensor AHU-3 Return air sensor AHU-2 Rm sensor AHU-1 Rm sensor AHU-1 Rm sensor AHU-2 Rm sensor AHU-2 TELC - Terminal equipment level controller Figure 12.2 Office building supervisory EMCS configuration, can implement traditional control strategies (see section 12.1.4) to improve building operating efficiency and achieve additional energy cost reductions. In addition to...

845 Gas or Liquidto Liquid Regenerators The Boiler Economizer

The economizer is ordinarily constructed as a bundle of finned tubes, installed in the boiler's breeching. Boiler feedwater flows through the tubes to be heated by the hot exhaust gases. Such an arrangement is shown in Figure 8.27. The tubes are usually connected in a series arrangement, but can also be arranged in series-parallel to control the liquid-side pressure drop. The air-side pressure drop is controlled by the spacing of the tubes and the number of rows of tubes. Economizers are...

53 Key Elements For Maximum Efficiency

There are several opportunities for maximizing efficiency and reducing operating costs in a boiler or other fired-system as noted earlier in Table 5.1. This section examines in more detail several key opportunities for energy and cost reduction, including excess air, stack temperature, load balancing, boiler blowdown, and condensate return. In combustion processes, excess air is generally defined as air introduced above the stoichiometric or theoretical requirements to effect complete and...

1452 Light Measurements

Reducing unnecessary lighting has psychological impacts that can far exceed any direct impact on energy consumption. To convince people that their areas are overlit or underlit, however, it is necessary to have well-established lighting standards and a way to compare existing conditions against those standards. The standards have been provided by the Illuminating Engineering Society in the IES Handbook and are discussed in Chapter 13 of this book. This instrument is typically designed to...

2854 Design and Equipment Integration

The purpose of this chapter is to familiarize the energy manager and facility engineer with the benefits and liabilities of ground-source heat pumps in their application to commercial buildings. It is beyond the scope of this chapter to fully explain the design requirements of a ground-source heat pump system. It is, however, important that the reader know the basic steps in the design process. The design of a ground-source heat pump system will generally follow the following sequence 1....

Lender

Individual or firm that extends money to a borrower EMP CHARACTERISTICS FACILITY CHARACTERISTICS EMP CHARACTERISTICS FACILITY CHARACTERISTICS Figure 25.14 Strategic Issues Financing Decision Tree. Figure 25.14 Strategic Issues Financing Decision Tree. with the expectation of being repaid, usually with interest. Lenders create debt in the form of loans or bonds. If the borrower is liquidated, the lender is paid off before stockholders receive distributions. The renter. The party that buys the...

25

When comparing projects, it is important to compare the costs and benefits over a common period of time. The intuitive sense of fairness here is based upon the recognition that most consumers expect an investment that generates savings over a longer period of time to cost more than an investment that generates savings over a shorter period of time. To facilitate a fair, comparable evaluation a common period of time over which to conduct the evaluation is required. This period of time is...

Vfd Attributes

These are just a few of the examples to show savings calculations. The advantages of VFD's include other aspects beyond energy savings, including improved productivity, reduced maintenance costs, and improved product quality, among others. The application of VFDs is relatively straight forward but a thorough analysis of the existing system and design of the future system is necessary to assure successful application. The load profile of the existing system is necessary to both determine savings...

1473 Monitoring Systems for Energy Maintenance Management

In addition to the sensors and monitoring equipment described above, several companies specialize in systems designed to show an operator the condition of equipment in the boiler room and related areas. Many of these units are available off-the-shelf. These include Hot water reset and boiler cutout controls (www. mge.com). These adjust the heating water temperature to a lower temperature when the ambient outside air is warm, and they turn off the heating system when it is no longer necessary....

Other Sources

American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). 1997. Ground Source Heat Pumps Design of Geothermal Systems for Commercial and Institutional Buildings. ASHRAE, Atlanta, GA. Cane, D., A. Morrison, and C. Ireland. 1998. Maintenance and Service Costs of Commercial Building Ground-Source Heat Pump Systems. ASHRAE Transactions, Vol 104(2) 699-706. Duffy, G. July August 1989. Commercial Earth-Coupled Heat Pumps Are Ready To Roll. Engineered Systems, pp. 40-47....

Design and Installation Guides

Chapter 29 Geothermal Energy. ASHRAE Handbook Heating, Ventilating, and Air-Conditioning Applications. American Society of Heating, Refrigerating, and Air- Conditioning Engineers, Inc. Atlanta, Georgia. Bose, J.E., J.D. Parker, and F.C. McQuiston. 1985. Design Data Manual for Closed-Loop Ground-Coupled Heat Pump Systems. American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., Atlanta, Georgia. Caneta Research, Inc. 1995. Commercial Institutional...

Contributors

Eric Angevine School of Architecture Oklahoma State University Stillwater, OK Barney L. Capehart Industrial Engineering University of Florida Gainesville, FL Clint Christenson Industrial Engineering Oklahoma State University Stillwater, OK Mechanical Engineering Department Texas A& M University College Station, Texas William E. Cratty Ventana Corporation Bethal, CT Energy Systems Laboratory Texas A& M University College Station, Texas Colorado Springs Utilities Colorado Springs, CO John...

Variable Speed Loads

The three common types of adjustable speed loads are variable torque, constant torque, and constant horsepower loads. A variable torque load requires much lower torque at low speeds than at high speeds. With this type of load, horsepower varies approximately as the cube of speed and the torque varies approximately as the square of the speed. This type of load is used in applications such as centrifugal fans, pumps, and blowers. A constant torque load requires the same amount of torque at low...

Eer 341 Cop104

Although neither COP nor EER is the efficiency of a chiller or air-conditioner, both are measures which allow the comparison of similar units. The term air-conditioning efficiency is commonly understood to indicate the extent to which a given air-conditioner performs to its maximum capacity. As discussed below, most equipment does not operate at its peak efficiency all of the time. For this reason, the seasonal energy efficiency ratio (SEER), which takes varying efficiency at partial load into...

10040

York international Corp. ice 200 - 60,000 York international Corp. ice 200 - 60,000 9. Thumann, Albert, Optimizing HVAC Systems The Fairmont Press, Inc., 1988. 10. Thumann, Albert and D. Paul Mehta, Handbook of Energy Engineering, The Fairmont Press, Inc., 1991. 11. Wong, Jorge-Kcomt, Dr. Wayne C. Turner, Hemanta Agarwala, and Alpesh Dharia, A Feasibility Study to Evaluate Different Options for Installation of a New Chiller With Without Thermal Energy Storage System, study conducted for the...

Tests and Evaluations

Obtain the following data T ppm of impurities in the makeup water to the deaerator from the treatment plant obtain average value through lab tests B ppm of concentrated impurities in the boiler drum water (blowdown water) obtain average value through lab tests lb hr MU lb hr of makeup water to the deaerator from the water treatment plant obtain from flow indicator lb hr BFW lb hr of boiler feedwater to each lb hr STM lb hr of steam output from each boiler...

232 Risk Analysis Methods

Risk analysis is a necessary first step in the process of minimizing the losses associated with unscheduled utility outages. The purpose of risk analysis is to understand the system under study and establish a knowledge base from which resources can be optimally allocated to counter known threats. This understanding comes from a systematic evaluation that collects and organizes information about the failure modes of a utility system. Once these failure modes are understood decisions can be made...

Asr

(15,500 lb hr) (0.746 kW hp) 8 lbs hp-hr Figure 7.7 Power speed ranges for single stage turbines. Courtesy Skinner Engine Co. Figure 7.6 Estimation of steam rates for smaller (< 3,000 HP) single-stage turbines. Courtesy Skinner Engine Co. a) Calculate TSR using equation 7.1 3412 Btu kWh 1201.7 - 1090.8 Btu lb b) Obtain steam rate from Fig. 7.6, ASR 38.5 lbs HP-hr. c) Calculate potential generation capacity (PGC) Ws(0.746 kW hp) Figure 7.7 shows that units ET-15 or ET-20 better match the...

Economic Data

Interest rate or Return on investment 10.0 Effective Income Tax Rate 30 Physical Plant Depreciation Period 7 years New Insulation Depreciation Period 7 years Incremental Equipment Investment Rate 3.47 MMBtu hr Percent of New Insulation Cost for Annual Insulation Maintenance 2 Percent of Annual Fuel Bill for Physical Plant Maintenance 1 Emittance of outer jacketing 0.10 Emittance of existing surface 0.80 Reference thickness for payback calculations 0.0 inches Insulation material GLASS FIBER...

1831039 1514955 1188747 1335610 1146699 1083518 990809 890520 846273 859050 871921 1514955 2703702 1368092 221393

Table 7.8 After tax discounted cash flow economic analysis. Utility Regulatory Policies Act of 197S With Regard to Small Power Production and Cogeneration, (4-1-90 Edition). 4. Estey P.N., et al., (19S4). A Model for Sizing Cogen-eration Systems, Proceedings of the 19th Intersociety Energy Conversion Engineering Conference Vol. 2 of 4, August, 19S4, San Francisco, CA. 5. Ganapathy, V. (1991). Waste Heat Boiler Deskbook, The Fairmont Press, Inc., Lilburn, CA. 6. Harkins H.L., (19S1), PURPA New...

7243 Cogeneration System Selection and Sizing

The selection of a set of candidate cogeneration systems entails to tentatively specify the most appropriate prime mover technology, which will be further evaluated in the course of the study. Often, two or more alternative systems that meet the technical requirements are pre-selected for further evaluation. For instance, a plant's CHP requirements can be met by either, a reciprocating engine system or combustion turbine system. Thus, the two system technologies are pre-selected for a more...

9103 Using Linear Regression for Envelope Analysis

The basic idea behind linear regression is that any physical relationship where the value of a result is linearly dependent on the value of an independent quantity can be described by the relationship where y is the dependent variable, x is the independent variable, m is the slope of the line that describes the relationship, and b is the y-intercept, which is the value of y when x 0. In the case of monthly building energy consumption, the monthly Degree Days, can be taken as the independent...

Simple Example

Consider a small company PizzaCo that makes frozen pizzas, and distributes them regionally. PizzaCo uses an old delivery truck that breaks down frequently and is inefficient. Assume the old truck has no salvage value and is fully depreciated. PizzaCo's management would like to obtain a new and more efficient truck to reduce expenses and improve reliability. However, they do not have the cash on hand to purchase the truck. Thus, they consider their financing options. 25.2.1 Purchase the Truck...

2167450074

Paragon Electric Company, 606 Parkway Blvd., Two Rivers, WI 54241 414-793-1161 Phonetics, Inc., 901 Tryens Road, Aston, PA 19014 215-558-2700 Process Systems, Inc., 100-A Forsythe Hall Dr, Box 240451, Charlotte, NC 28224 704-588-4660 Robertshaw Controls, 1800 Glenside Drive, Richmond, VA 23261 804-289-4200 Scientific Atlanta, 4300 Northeast Expressway, Atlanta, GA 30340 404-449-2902 Snyder General, Inc., 13600 Industrial Park Blvd., Minneapolis, MN 55440 612-553-5330 Solidyne Corp., 1202...

46 Time Value Of Money Concepts

And loaning it to earn interest, generates a sum greater than 100 one year from today and thus is preferred. The amount in excess of 100 that would be available depends upon the interest rate being paid by the bank. The next section develops the mathematics of the relationship between interest rates and the timing of cash flows. The second factor which leads to the time preference associated with money is inflation. Inflation is a complex subject but in general can be described as a decrease in...

Energy Management

The material in this section is repeated verbatim from the first and second editions of this handbook. Mr. Roger Sant who was then director of the Energy Productivity Center of the Carnegie-Mellon Institute of Research in Arlington, VA, wrote this section for the first edition. It was unchanged for the second edition. Now, the fourth edition is being printed. The principles developed in this section are still sound. Some of the number quoted may now be a little old but the principles are still...