NBS

PUBLICATIONS

Calculations of Maximum Allowable

Heat Losses for Various Shallow

Trench Heat Distribution Systems

A111D2 71771fi

NBSIR 87-3617

Jin B. Fang

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Environment Division

Gaithersburg, MD 20899

November 1987

Prepared for: Tri-Service Building Materials Committee

Headquarters, U.S. Army Corps of Engineers

Washington, DC 20314-1000

U.S. Navy, Naval Facilities Engineering Command

Alexandria, VA 22332-2300

U.S. Air Force, Air Force Engineering and

^ ^ ^ OABiioes Center hoc—Air Force Base, FL 32403-6001

' 100

.U56

87-3617 I 1987 !

NBSIR 87-3617

Research Information Center

National Bureau of Standards

Gaithersburg, Maryland 20899

CALCULATIONS OF MAXIMUM ALLOWABLE

HEAT LOSSES FOR VARIOUS SHALLOW

TRENCH HEAT DISTRIBUTION SYSTEMS

Jin B. Fang

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Environment Division

Gaithersburg, MD 20899

November 1987

Prepared for: Tri-Service Building Materials Committee

Headquarters, U.S. Army Corps of Engineers

Washington, DC 20314-1000

U.S. Navy, Naval Facilities Engineering Command

Alexandria, VA 22332-2300

U.S. Air Force, Air Force Engineering and

Services Center

Tyndall Air Force Base, FL 32403-6001

U.S. DEPARTMENT OF COMMERCE, C. William Verity, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

ABSTRACT

The calculation of heat losses for shallow trench underground heat

distribution systems was performed using a finite element computer program.

The finite element analysis solved a two-dimensional steady-state heat

transfer problem for two insulated pipes in a rectangular trench with

surrounding soil. A life-cycle cost analysis was performed to determine the

cost of construction and annual energy cost associated with pipe heat loss

for underground concrete trench systems of different trench dimensions and

insulated pipe sizes. Procedures for determining the pipe heat losses

associated with the minimum life-cycle cost and the corresponding optimum

insulation thickness for shallow trench distribution systems are presented.

Based on the results of the economic analysis, the maximum allowable heat

losses and the insulation thickness for underground pipes were determined

and tabulated for a range of pipe sizes and fluid temperatures, various

levels of fuel costs, and for a known undisturbed earth temperature and soil

thermal conductivity.

Keywords: district heating and cooling; finite element method; fuel energy

cost; heat loss; life-cycle cost analysis; pipe insulation thickness;

shallow trench; underground heat distribution system.

1
TABLE OF CONTENTS

Page

1 . Introduction 1

2. Pipe Heat Loss Calculations 3

3. Comparison Between Finite Element and Thermal Analyzer Programs 6

4. Life-Cycle Cost 8

5. Conclusions 14

6. Acknowledgment 16

7 . References 16

LIST OF TABLES

Table 1 A Comparison of the Pipe Heat Losses Calculated from

Temperature Dependent Thermal Conductivity with those

Obtained from Constant Thermal Conductivity of Calcium

Silicate Insulation 18

Table 2 Comparisons of Calculated Results from Finite Element

Computer Program with Those by the Thermal Analyzer

Program for Various Concrete Trench Systems 19

Table 3 Effect of Trench Dimension on Pipe Heat Losses 20

Tables A-1 Maximum Allowable Heat Losses and Economic Insulation

through Thickness for Hot Water Supply and 150 F Return Pipes

A-13 and for Energy Cost of $3 through $15/MBtu 35

Tables B-1 Maximum Allowable Heat Losses and Economic Insulation

through Thickness for Steam Supply and 150 F Condensate Pipes

B-13 and for Energy Cost of $3 through $15/MBtu 61

Tables C-1 Maximum Allowable Heat Losses and Economic Insulation

through Thickness for Hot Water Supply and 250 F Return Pipes

C-13 and for Energy Cost of $3 through $15/MBtu 87

ii
LIST OF FIGURES

Pa-fa-e Figure 1. Concrete Shallow Trench Underground Heat Distribution

System 21

Figure 2. Thermal Conductivity Variation with Temperature for

Calcium Silicate Insulation 22

Figures 3 Construction Cost for a Shallow Trench System

through 14. Containing Two 1-inch through IS-inch Insulated Pipes 23

Figures 15 Construction Cost for a Shallow Trench System

through 25. Containing a 2-inch through 18-inch Supply and a 1-inch through 10-inch Return Insulated Pipes 29

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1 . In troduc t ion

The production and supply of hot water, chilled water, or steam by a

centralized plant is more efficient and economical than production and

supply using a number of smaller units. However, this advantage is not possible

unless the cost of delivering the working fluid through pipe-lines to the

point of use is low. The cost of constructing a distribution pipe-line

network generally accounts for the major portion of the total cost of

acquiring a district heating and cooling system. In addition, the operating

characteristics of the piping system, such as pipe heat loss, operation

reliability and maintenance expense, are of major consideration. An

extensive financial loss and intensive labor cost will be involved if a

system outage occurs. The heat loss through the underground distribution

system consumes a large portion of the system fuel energy cost, and the

unavoidable escalation in future fuel prices will make such losses more

important. Knowledge of pipe heat loss conditions is essential for initial

planning and detailed design, choice of materials, and estimated cost of an

underground heat distribution system.

The military installations currently maintain approximately 6,000 miles

(11,110km) of heat distribution systems [l]. Some of these systems have

required repair or replacement due to excessive heat loss resulting from

deteriorating thermal pipe-insulation and/or corroding pipes and conduits.

Recently, Pan Am [1] and Parsons [2] conducted comparisons of directly

buried conduit versus shallow concrete trench heat distribution systems for

delivering steam and hot water using life-cycle cost analysis to assess

1
their relative merits. The findings of both studies did not agree with each

other, especially for the distribution pipe-lines involving large diameter

pipes. The discrepancy was probably due to the estimated cost data. Hov;ever,

continued construction of shallow concrete trench systems is anticipated

because of their reduced maintenance and repair costs, easy access for

inspection and testing, and relatively dry conditions for minimizing possible

based OR life-cycle cost analysis was developed at NBS for calculating the

maximum allowable heat loss for directly buried conduit underground systems

[3l, and the results were included in the guide specification for military

construction, CEGS-15705 [4], The methods of determining the minimum lifecycle cost heat loss and the optimum insulation thickness for shallow trench

systems will -complement the procedure already developed for directly buried

conduit systems.

This report presents the procedures to calculate the fuel energy cost

associated with pipe heat loss, a set of tables listing the maximum allowable

heat loss per unit length of piping section, and the corresponding economic

insulation thickness for heat supply and return pipes installed in shallow

trench distribution systems. The minimum life-cycle cost heat loss data are

prepared based on a range of pipe sizes, insulation thicknesses, energy

prices, soil and insulation thermal conductivities and a known undisturbed

earth temperature. This report also presents the estimiated material and

installation costs for constructing various distribution systems of different

trench dimensions and insulated pipe sizes.

2
2. Pipe Heat Loss CalculaC ions

The heat transfer process in a rectangular concrete trench containing a pair

of insulated circular pipes and the surrounding soil is quite complex due to

the involvements of complicated geometries, composite materials, and at

least two modes of heat transfer - conduction and convection. Tlierefore,

the solution of this non-linear type of heat transfer problem by exact

methods is not possible.

The heat loss per unit length in a concrete shallow trench underground heat

distribution system was calculated using a recently developed computer

simulation program [5, 6]. This program has applied the finite element

method to a steady-state, two-dimensional, rectangular concrete trench

containing two insulated pipes as shown in Figure ’1. A twin pipe system

comprised of a heat supply and a return line is modelled in the computer

program since it is the most commonly used shallow trench heat distribution

system. The heat loss calculations are based on a two-dimensional heat flow

and account for heat transfer from the pipe fluid through the pipe insulation,

the air space, and the concrete trench v/alls to the surrounding soil and

ambient air. Convective heat transfer in the air space between the pipe and

trench wall surfaces is treated by assuming an effective conductance for

natural convection in the trench. The surface resistance to convective heat

transfer between the ambient air and the ground surface in the vicinity of

the shallow trench is treated as being contained in an equivalent soil layer

[6]. The effect of radiant exchange between the pipes and trench walls is

assumed to be negligible due to low emissivity of the aluminum jacket

surface. The boundary conditions are the average temperatures of working fluids

3
f .owing inside the circular pipes, and the undisturbed earth teoperatines

along the perimeter of the earth region.

The computer program contains a predesigned finite element mesh with 80

nodal points and 130 triangular elements representing the outer boundary

earth region, concrete trench walls, top concrete cover, pipe insulation,

and the air space between the insulated pipes and the trench walls. The

external boundary temperatures including the nodal points around the outer

surfaces of the circular pipes and along Che outermost perimeter of the

outer earth region surrounding the shallow trench system are prescribed from

the data input for computer runs. The system of simultaneous equations

solves for the remaining nodal point temperatures using Che Gaussian

elimination method. The computer code is written in FORTRAN 77 programming

language and implemented on an IBM personal computer.

The rate of heat loss from an insulated pipe can be obtained using the

following equation derived from one-dimensional, steady-state, radial heat

conduction in a composite pipe, based on Che average temperature difference

across a circular cylindrical shell of pipe insulation layer:

(2t) kj (T. - T^)

q = ( 1 )

( 12 )

where q

= the heat loss rate per unit length of the insulated pipe, Btu/h*fC

( W/ m)

2 . kj = the therma 1 c onduc t ivi ty of insu la t ion ina ter ia 1 , B tu * in/ h * f t *F

(W/m*K)

4
7q = outside radius of the insulation layer, ft (m)

7^ = inside radius of the insulation layer, ft ( ra)

and = the surface temperature of the insulation layer at inner

and outer radii, respectively, F ( C)

The pipe insulation is the major resistance to heat transfer for an insulated

the pipe, the thermal resistance of the pipe wall, and that of the metal

jacket are small and can be assumed negligible. A detailed description and

the input data required for executing the computer program, along with the

results of some sample calculations , were sumiaai ixed in previous stud ies [ 6 ] .

In order to obtain a more realistic prediction of the pipe heat losses,

especially a't higher pipe fluid temperatures, a subprogram was added to this

finite element computer program to account for the temperature dependency of

the pipe-insulation thermal conductivity. The thermal conductivity of

calcium silicate, which is- resistant to aging during periodical wetting and

drying and commonly used for pipe insulation, as a function of the speciment

mean temperature [?] is shown in Figure 2. In this figure, the thermal

conductivity increases with increasing temperature. The data used to

generate the curve in Figure 2 are stored in a computer subprogram, which is

formulated based on the table look-up procedure to provide the temperature

dependent thermal conductivity value to be used for each triangular element

of pipe-insulation. Since the mean temperatures of the earth surrounding

the trench and the pipe insulation are dependent upon the rates of heat

transfer through them, an iterative procedure is used along with adjustment

of soil and insulation thermal conductivities until the heat loss from the

underground pipes achieves a steady-state condition.

5
Computer calculations were^ performed to determine the effect of thermal

conductivity variations with temperature on pipe heat loss for two 6-inch

(150 mm) steel pipes installed side by side in a 4.08 ft (1.24 m) wide by

2.92 ft (0.89 m) high concrete trench having 6 in. (152 mm) thick walls and

cover. The top cover was laid flush with ground level. The temperature of

hot water flowing in the heat supply pipe was 385 F (196 C) and the return

pipe temperature was 210 F (99 C) . The pipes were insulated with 3.5 in.

(89 mm) thick calcium silicate encased in an aluminum jacket, allowing 4 in.

(102 mm) of separation between outer surfaces of the carrier pipes. The

earth in the vicinity of the shallow trench had annual average temperature

of 56 F (13 C) and thermal conductivity of 15 Btu *in/h* ft^ ’F (2.16 W/m'K).

A comparison of the heat loss values calculated from temperature dependent

insulation thermal conductivity with those obtained from the constant

2 . thermal conductivity of 0.44 Btu’in/h'ft F (0 .063 h'/m’K) for various

insulation thicknesses is given in Table 1. For this sample case, the

temperature dependent thermal conductivity gave approximately 3 to 4%

greater total heat loss values compared to the constant thermal conductivity.

3. Comparison Between Finite Element and Thermal Analyzer Programs

The thermal analyzer computer program, TASTAP , developed based on the

application of finite difference technique was recently employed for

calculating the pipe heat losses of shallow trench and directly buried

conduit heat distribution system.s [2]. The capabilities of this finite

6
difference cor.;puter simulation program were described briefly in Parsons'

report [2]. There is a lack, of field data on pipe heat loss, temperature

distributions of trench air, concrete walls, and soil in the vicinity of

underground systems, which are available to be utilized for validation of

the predictive methods. Some calculations using the finite element computer

program were carried out on typical shallow trench systems with different

pipe sizes and fluid temperatures, and the results were compared with the

predictions made from the thermal analyzer program TASTAP . An average

ground temperature of 55 F (12.8 C) , a 6 in. (152 mm) thick trench walls and

cover, and the thermal conductivities of soil, concrete and pipe insulation

equal to 15, 8, and 0.444 Btu * in/ h* f t^ 'F (2.16, 1.15, and 0.064 W/m*C),

respectively, were used in these calculations.

The heat losses predicted by the finite element and the finite difference

computer programs for the carrier pipes installed in various concrete trench

systems for hot water and steam distributions are shown in Table 2. In

general, for the heat supply pipes the calculated heat loss values from the

finite element model are consistently about 6 percent smialler compared to

the results of the thermal analyzer. The differences in heat loss values

tend to be greatest for the largest pipe diameter. With the exception of

one case involving a 12 in. (305 mm) pipe carrying hot water, the finite

element model used in this study gives approximately 11 percent greater heat

loss values for the return pipes in comparison to the finite difference

technique. The total pipe heat losses predicted by the finite element

program agree within 4 percent from the thermal analyzer predictions.

7
The effect of trench size on pipe heat losses using the finite element

computer program was studied by systematically varying the inner drr.iension

of the concrete trench containing the two 6-in. (152-mm) insulated pipes.

The pipes are wrapped in a 3 in. (76.2 mm) thick insulation and aluminum

jacket, and transport hot water at 350 F (177 C) and 285 F (141 C) , respectively.

The centers of these pipes are located at 2.75 ft (0.84 m) and 3.08 ft (094

m) below the ground surface and are separated by a horizontal distance of 1.90

ft (0.58 m) . The results of this parameter analysis are shown in Table 3.

The trench dimension has little effect on pipe heat loss predictions as

illustrated in the table. For example, doubling the trench dimensions from

3 X 3 ft (0.91 X 0.91 m) to 6 X 6 ft (1 .83 x 1 .83 m) , causes only a 1.5%

increase for the pipe heat loss.

4. Life-Cycle Cost

The total life-cycle cost of an underground heat distribution system is the

sum of the cost of acquisition, yearly maintenance and repair cost, and

yearly fuel energy cost including adjustment for future escalation in fuel

prices over the life of the system. The total life-cycle cost (LCC) can be

expressed as follows:

LCC = MIC + 3760 * Q

* EC * UPW + MRC (2)

where MIC = the material and installation costs, ($/ft of the underground

system)

Q

= the system heat loss rate, which is equal to the sum of the heat

loss rates of two pipes, (Btu/h*ft); and 8760 is a conversion

f ac tor

EC = the equivalent fuel energy cost, ($/MBtu)

8
= 100 (FC/EF) , in which FC is fuel cost, ($/MBtu), and EF ig^-plant

fuel conversion efficiency, (%)

UPW = the modified uniform present worth factor adjusted for ,.future

escalation in fuel prices

MRC = the maintenance and repair costs, ($/ft of the system) .

The concrete trench had different overall dimensions to accommodate

pipe sizes and insulation thicknesses and to maintain specified clearances

such as at least 4 inches (102 mm) of space existing between the insulated

pipes, a minimum of 3 inches (76 mm) between the piping and adjoining trench

walls, and at least 6 inches (152 mm) from the bottom surface o^, the pip.e to

the trench floor as specified in the design guide [8] and shown- in Figure 1.

A minimum inside width of 2 ft (0.61 m) was used for all concrete trehches

since the trenches smaller than this were difficult to work wijfh- during the

stage of construction. In district heating and cooling, high temperature

hot water and pressurized steam are recognized as the most effective and

economical working media. For hot water distribution in a twin pipe system,

V.- both the heat supply and the return lines generally have the sam^pi-pe size.

However, the return condensate line for steam distribution ji-”®' usually a

smaller diameter pipe than the supply line due to the volume reduction of

the steam condensing to hot water.

The cost of materials and labor employed for constructing ^fijrllow trench

heat distribution systems of various pipe sizes and trench dimensions can be

calculated using the cost data and estimate procedures presented in

references [2, 3, 9, 10]. Construction costs for shallow trench underground

heat distribution systems are estimated and shown as a function of

9
insulation thickness for nominal pipe sizes ranging from 1 to 18 inches (25

to 457 mm) for hot water and steam distributions in Figures 3 to 25 . As

illustrated in the figures, the construction costs for both the concrete

trench and the insulated pipes increase with thicker pipe insulation. The

estimated construction costs for some concrete trench and distribution

piping systems were compared with those developed in the sample cases

treated in the life-cycle cost analysis of underground heat distribution

systems L2] , and found to be in good agreement with those reported capital

cost data.

The equivalent energy cost per unit length, or the yearly cost of lost

energy considered as an operating expenditure, of the shallow trench system

was calculated using the computed pipe heat losses obtained as the outputs

from the computer program, and the fuel energy cost adjusted over the life

of the system by taking projected energy price changes into account. The

plant fuel conversion efficiency ranges between 50 and 90% depending on the

type of boiler utilized. In all life-cycle cost calculations, the fuel to

heat conversion efficiency at the plant is assumed to be 80%.

The energy price is assumed to escalate annually in accordance with the data

on the inflation rate of natural gas prices for the period 1985 to 2010 as

projected by the U.S. Energy Information Administration [11]:

Escalation Period

(’^ear)

Fuel Price Inflation Rate

Ln

1-5

6-10

11-15

16-20

21-25

4.11

6.12

4.85

4.11

4.24

10
The modified uniform present worth factor (UPW) was calculated based on a

10% discount rate over a 25 year life for the underground shallow trench

distribution system, and the fuel price escalation rate project by the U.S.

Energy Information Administration for 1985 through 2010 , using the following

equation [12]:

I-"®! N2 1+S2 j

UPW = 2 ir—) + (77:^) Z j=l j=l

1 +ei Ni l+eo No No 1 +eo j + (r-“) (—) E (rrr) 1+d

J=1

1+d 1+d

1+ej^^ Nj^ l+e2 N2 l+e3 N3 N^ 1+e^ j + (,.,) ^1+d

^ J=1

1+d 1+d 1+d

( 3 )

1+^1 Ni 1+eo No 1+eo No l+"eA Na Nc 1+ec j + (—) (7-“) (—) z (7-r)

J=1

1+d 1+d 1+d 1+d

l+er

where y ( ) = (r ) [1 - (

-—- ) 1

• ii 1+d d-e, 1+d j=l k

Nj^ = the length of the period for a given escalation rate in a given period,

( year)

d = the discount rate, (%)

= the rate of escalation in each of Nj^ period.

Assuming no salvage value for the underground shallow trench system at the

end of a 25 year life-cycle, the modified uniform present worth factor, UPW

is found to be 14 . 16%.

Based on the cost data of a recent survey of field installations [ 1 ], the

present values over the 25 year life-cycle of annually recurring routine

11
maintenance and nonannually recurring repair costs for a typical shailov/

trenc h system were computed and found to be $1.72 per foot ($5.64 per meter)

and $0.09 per foot ($0.30 per meter), respectively. These main tenanc e and

repair c os ts were low compared to the sy s temc ons t rue ti on cost and operational

costdue topipeheat losses and therefore neg lec ted in li f e-cyc Le cost analysis .

For minimum life-cyc le cost or maximum ailowab leheat loss calculations, the

working fluid temperatures for the heat supply pipe were varied between 150

tand 500 F (66 to 260 C) with an increm.ent of 50 F (27.8 C) , and temperature

levels of either 150 F (66 C) or 250 F (121 C) were selected for the return

pipe fluid tem.peratures . Different pipe sizes ranging from 1 to 18 inches

(25 to 457 mm) in nominal diameter and insulation thicknesses varying from 1

to 6 inches (25 to 152 mm) in increments of 0.5 in. (12.7 mni) were selected

for heat loss calculations and cost analysis. In order to reflect a variety

of fuel energy costs, the selected values of fuel cost ranged from $3.00 to

$15.00 per million Btu ($2.84 to $14.22 per giga joule). All calculations

were carried out based on an annual average earth temperature of 55 F (12.3

C) , a soil thermal conductivity of 10 Btu . in/h . f t2 .F ( 1 .44 W/m.C) , a 6 in.

(152 mm) thick trench wall , a cone re te therma 1 conduc t ivity of 9 .7 Btu. in/h . f t2 .F

( 1 .4 W/m .0 ) , an annua 1 amp 1 i tude of the monthly average tempei'a ture cycle of

23 F (-5 C) [6, 13], and heat losses determined for the month of January.

The extreme seasonal temperatures were selected as the ex terna 1 tempera tures

for buried piping design considerations, and the choice of January resu) ted

in the computed pipe heat loss to be approximately 5% greater than annual

heat loss.

12
Computer calculations of the life-cycle cost for the cost of capital

investment and the yearly energy cost associated with the heat lost from the

pipes were carried out for each pipe size and specified fluid temperatures,

and for various insulation thicknesses starting from 1 in. (25 mm) with an

increment of 0.5 in. (12.7 mm) . From a set of life-cycle costs derived for

a range of insulation thickness, the maximum allowable heat losses for the

supply and the return lines were selected as those heat losses for which the

life-cycle cost was at a minimum for a specified fuel cost and pipe size.

The pipe insulation thickness corresponding to these maximum al lowab le heat

losses is the economic insulation thickness. This optimum insuLaticn

thickness is equivalent to the best economic balance between the total cost

for constructing the shallow trench system and insulating the distribution

piping , and the resulting energy saving over the life time of the underground

system.

Tables A-1 through C-13 present the max imum a 1 lowab le hea t losses (MAHL) and

the corresponding economic insulation thickness (EIT) of the insulated pipes

for shallow trench heat distribution systems at selected pipe temperatures

and fuel cost. These tables are divided into three sets: the "A" tables

present the MAHL and EIT values derived based on a 150 F (66 C) return pipe

temperature for a high temperature hot water distribution system, the "B"

tables contain MAHL and EIT data based on a 150 F (66 C) condensate return

pipe temperature for a pressurized steam system, and the "C" tables present

the MAHL and EIT values based on a 250 F (121 C) return pipe f uid tempera ture

for a hot water distribution system.

13
As illustrated in the tables, the heat loss from the heat supply pipe

increases as the temperature of the work ing med i urn flowing inside the supply

pipe increases , causing a larger temperature gradient between the inner and

outer surfaces of the pipe insulation. However, the heat loss of the return

pipe decreases as the supply pipe fluid temperature increases due to two

factors; the increased insulation thickness and heat gain by convection heat

transfer from the adjoining supply pipe. The effect of temperature variations

of the return pipe on the maximum allowable heat losses can be determined by

comparing the heat loss values in "A" table and those in ”C" taole for a

given pipe size and fuel cost, and a selected working medium temperature of

the supply pipe. The results indicate that a noticeable increase in the

return pipe temperature does not cause any significant decrease in the heat

loss value of the supply pipe. The heat loss of the return pipe at a

temperature greater than 150 F (66 C) for a given pipe size, supply pipe

fluid temperature and fuel cost can be found from one of the "A" tables, and

is equal to the heat loss value for the supply pipe at specific return pipe

temperature. Using equation 1 and assuming a constant temperature for the

outer surface of the insulation layer, this heat loss value is then revised

to account for the reduction in pipe heat loss due to increased insulation

thickness for specific return and supply pipe fluid temperatures. It should

be noted that the maximum allowable heat loss and the corresponding economic

insulation thickness data presented in the tables would change for different

insulation materials, trench configurations and design conditions.

14
5. Conclusions

The heat losses from two insulated pipes installed in a shallov; trench

underground heat distribution system were calculated using a computer

simulation program developed based on the application of Che finite element

method to two-dimensional, steady state heat conduction problem. A more

accurate prediction of heat flows in an underground system and surrounding

soilcanbe obtained us ing temperature-dependent , variable thermal conductivities

for the pipe insulation. In general, the pipe heat losses predicted from

the finite element model used in this study are in reasonab ly good agreement

with the predictions of the finite difference computer model TASTAP . The

effect of trench dimension on pipe heat losses was studied numerically using

the finite element computer program and found to be insignificant. The

material and labor costs for construction of concrete trenches distribution

systems including insulated piping of various pipe sizes and insulation

thicknesses , and c one rete trench of differentd imens ions are developed , and

these cost data are presented graphically.

Life-cycle cost analysis was performed for shallow trench systems to obtain

the pipe heat loss and the insulation optimum balance between the costs of

capital investment including the costs of constructing d is Ur ; bi t ion piping

and installing additional insulation, and the resulting energy saving,

calculated over the expected life of tlie underground system for projected

growth of the fuel price. The procedures for calculating the energy cost

attributed to*the pipe heat loss and for determining the maximum a 1 lowab le hea t

loss , which is defined as that heat loss rate for which the total owning and

operating cost of the system is at a minimum, for an underground concrete

15
trench system are described. Based on the resurts of the cost analysis, the maximum

allowable heat i.osses and the most economic insulation thickness for undergrounu

pipes distributing steam and hot water, were determined and taouiated for a ran^e o:

fluid temperatures and pipe sizes, various levels of fuel cost, for fixed values of

earth temperature and soil thermal conductivity.

6 . Acknowledgment

This invest igat ion was conduc ted under the Tri- Service Building Materials Invest iga t icna 1

Program and was jointly sponsored by the Headquarters, U.S. Army Corps of Engineers;

U.S. Navy, Naval Facilities Engineering Command; and the U.S. Air Force, Air Force

Engineering and Services Center. The author would like to thank Sandra Krause’ of

NBS for her help in preparing the figures used in this report, and Robin Bicicel of

NBS for her skillful typing of the manuscript of this reporting including numerous

tables.

7 . References

1. Pan Am World Services, Inc., "Heat Distribution Systems Life-Cycle Cose iinalysisCom.parison Between Direct Buried and Shallow Trench Systems," F.eport 130319, July

1985.

2. Parsons Corporation, "Life-Cycle Cost Analysis - Comparison Between Direct Buried

Conduit and Shallow Concrete Trench Underground Heat Distribution Systems,"

February 1986.

3. Kusuda, T., "Maximum Allowable Heat Losses for Underground Heat Distribution

Systems Based Upon Life-Cycle Cost Analysis," a report for Tri-Service Committee

on- Underground Heat Distribution Systems, April 1984.

4. U. S. Army Corps of Engineers, Guide Specification Military Construction,

Underground Heat Distribution System and Condensate

16
Return System - Prefabricated or Pre-Eng ineered Types', CEGS-15705, f'lay

1986 .

5. Kusuda, T., "FEMTKE - Finite Element Method Computer Program for

Underground Heat Distribution System Heat Loss Calculations a report'

for Tri-Service Committee on Underground Heat Distribution Systems,

January 1984.

6. Fang, J. B., "Minimum Life-Cycle Cost Heat Losses for Shallow Trench

Underground Heat Distribution Systems," NBSIR 86-3381 , May 1986 .

7. U.S. Department of Energy, 'Economic Thickness for Industrial Insulation,'

The Fairraont Press Inc., Atlanta, GA, 1983 .

8. U.S. Army Corps of Engineers, Guide Specification Military Construction,

'Heat Distribution Systems Outside of Buildings - Concrete Shallow

Trench Systems,' CEGS - 15709, June 1986.

9. Means Mechanical Cost Data, 7th Annual Edition, Robert Snow Means Co.,

Kingston, MA, 1984.

10. Building Construction Cost Data 1985, 43rd Annual Edition, Robert Snow

Means Co., Kingston, MA , 1985.

11. Lippiatt, B. C., Weber, S. F. and Ruegg , R. T. , "Energy Prices and

Discount Factors for Life-Cycle Cost Analysis," NBSIR 85-3273, November

1985.

12. Ruegg, R. T., "Life-Cycle Costing Manual for the Federal Energy

Management Programs," National Bureau of Standards Handbook 135,

( Rev.) , May 1982 .

13. Kusuda, T. and Achenbach, P. R., "Earth Teraperatuie and Thermal

Diffusivity at Selected Stations in the United States," ASHPxAE T r ansactions .

Vol. 71, Part 1, pp. 61-75 , 1965 .

17
TABLE 1

A Comparison of the Pipe Heat Losses Calculated from

Temperature Dependent Thermal Conductivity with Those Obtained

from Constant Thermal Conductivity of Calcium Silicate Insulation

Insulation

Thickness

( inch)

Heat Loss Rate ("Btu/h—ft)

Diff

(%)

Constant K Temn . Denendent K

Pine 1 Pine 2 Total Pine 1 Pine 2 Total

1.0 238 94 332 251 94 345 3.8

1.5 177 74 251 187 74 260 3.5

2.0 144 62 206 151 62 213 3.3

2.5 124 54 178 129 54 183 2.7

3.0 109 48 157 114 48 162 3.1

3.5 98 44 142 103 43 146 2.7

4.0 90 40 130 94 40 134 3.0

5.0 79 35 114 82 35 117 2.6

6.0 70 32 102 73 32 105 2.9

18
TABLE 2

2 .

Note

Comparisons of Pipe Heat Loss Values Calculated by

Finite Element Computer Program with Those by the

Thermal Analyzer Program for Various Concrete Trench Systems

High temperature hot water systems with pipe temperatures of 350 F and

285 F:

Nominal Pipe 1 Diameter (Inch)

Insulation Thickness 2

( Inch)

Heat Loss (Btu/h'ft)

Supply Pipe (350 F) 46.57 (47.30)

Return Pipe (285 F) 35.85 (34.75)

Total

12

96.84 (97.00)

73.74 (71.69)

82.42 (82.05) 170.58 (168.69)

154.06 (171.97)

115.61 (126.80)

269.67 (298.77)

Pressurized steam systems with pipe temperatures of 350 F and 160 F:

Nominal Pipe

Diameter (Inch)

Supply Pipe 1

Return Pipe 3/4

Insulation Thickness

(Inch)

Supply Pipe 2

Return Pipe 2

Heat Loss (Btu/h-ft)

12

6

3

2.5

Supply Pipe (350 F) 47,,05 (49..68) 98,.97 (101 .68) 159,,98 (181 .28)

Return Pipe (160 F) 14,,08 (10,.94) 23,.10 (19. 16) 29,.01 (25. 01)

Total 61,.13 (60..62) 122,.07 (120 .84) 188.,99 (206 .29)

The pipe heat loss values in brackets are predicted by the finite

difference thermal analyzer program TASTAP.

19
TABLE 3

Effect of Trench Dimension on Pipe Heat Losses

Concrete Trench

Inner Dimension

Cwidth X heieht)

Pine Heat

Sunnlv Pine

Loss CBtu/h—ft'

Return Pine Total

3 ft X 3 ft 97.02 73.35 170.37

4 ft X 4 ft 96.84 73.74 170.58

5 ft X 5 ft 97.19 74.08 171.27

6 ft X 6 ft 97.57 74.44 172.01

20
Ground

surface
THERMAL

CONDUCTIVITY

(Btu

• in

/hft^-F)

MEAN TEMPERATURE (F)

Figure 2. Thermal Conductivity Variation With Temperature

for Calcium Silicate Insulation

22
Construction

Cost

($/Ft)

Construction

Cost

($/Ft)

500 Distribution Piping + Concrete Trench

O Total Cost

M30 -

JOO -

200

100

1.5 2.5 3.5

Insulation Thickness (Inch)

Figure 3. Construction Cost for a Shallow Trench System Containing Two 1-inch Insulated Pipes

Figure 4. Construction Cost for a Shallow Trench System Containing Two 2-inch Insulated Pipes

23
Construction

Cost

($/Ft)

C

onstruction

Cost

($/Ft)

Figure 5. Construction Cost for a Shallow Trench System

Containing Two 3-inch Insulated Pipes

Figure 6. Construction Cost for a Shallow Trench System

Containing Two 4— inch Insulated Pipes
Construction

Cost

($/Ft)

Construction

Cost

($/R)

500

Figure 7. Construction Cost for a Shallow Trench System

Containing Two 5-inch Insulated Pipes

Figure 8. Construction Cost for a Shallow Trench System

Containing Two 6-inch Insulated Pipes

25
Construction

Cost

($/Pt)

Construction

Cost

($/Ft)

Figure 9. Construction Cost for a Shallow Trench System

Containing Two 8-inch Insulated Pipes

Figure 10. Construction Cost for a Shallow Trench System

Containing Two 10-inch Insulated Pipes

26
Construction

Cost

($/Ft)

Construction

Cost

($/F0

Figure 11. Construction Cost for a Shallow Trench System

Containing Two 12-inch Insulated Pipes

Figure 12. Construction Cost for a Shallow Trench System

Containing Two 14-inch Insulated Pipes

27
Construction

Cost

($/Ft)

Construction

Cost

($/Ft)

Figure 13. Construction Cost for a Shallow Trench System Containing Two 16- inch Insulated Pipes

Figure 14. Construction Cost for a Shallow Trench System

Containing Two 18-inch Insulated Pipes

28
Construction

Cost

($/Ft)

Construction

Cost

($/F0

Figure 15. Construction Cost for a Shallow Trench System Containing

a 2-inch Supply and a 1-inch Return Insulated Pipes

Figure 16. Construction Cost tor A Shallow Trench System Containing

a 3-inch Supply and a 1.5-inch Return Insulated Pipes

29
500 Distribution Piping + Concrete Trench

O Total Cost

Insulation Thickness (Inch)

Figure 17. Construction Cost of a Shallow Trench System Containing

a 4-inch Supply and a 2-inch Return Insulated Pipes

Figure 18. Construct Cost for a Shallow Trench System Containing

a 5-inch Supply and a 2.5-inch Return Insulated Pipes

30
Construction

Cost

Ct/F^t)

Figure 19. Construction Cost for a Shallow Trench System Containing

a 6-inch Supply and a 3-inch Return Insulated Pipes

Figure 20. Construction Cost for a Shallow Trench System Containing

a 8-inch Supply and a 4-inch Return Insulated Pipes

31
Figure 21. Construction Cost for a Shallow Trench System Containing

a 10-inch Supply and a 6-inch Return Insulated Pipes

u.

'j) 0

O

c

0

o

3w

cnc

0

o

Figure 22. Construction Cost for a Shallow Trench System Containing

a 12-inch Supply and a 6-inch Return Insulated Pipes

32
Construction

Cost

($/Ft)

Construction

Cost

($/Ft)

Figure 23. Construction Cost for a Shallow Trench System Containing

a 14~inch Supply and a 8-inch Return Insulated Pipes

Figure 24. Construction Cost for a Shallow Trench System Containing

a 16-inch Supplv and a 8-inch Return Insulated Pipes

33
Construction

Cost

($/Ft)

Figure 25. Construction Cost for a Shallow Trench System Containing

a 18-inch Supply and a 10-inch Return Insulated Pipes

34
TABLE A-l.a

Maximum Allowable Heat Losses (Btu/h‘ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $3/M Btu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Type 150 200 250 300 350 400 450 500

1 S 22 .2 26,.2 35 .3 45 .1 55 .6 66 .6 77,.8 89 .5 R 22 .2 17,.3 17 .1 16 .8 16 .5 16 .2 15 .9 15 .6

2 S 25 .0 37,.3 50 .5 54 .0 66 .6 70 .0 81 .8 94 .0

R 25 .0 24 .6 24 .1 20 .0 19 .6 17 .2 16 .9 16 .6

3 S 32 .3 48,.4 54 .1 69 .2 85 .3 88 .6 92 .6 106 , 5 R 32 .3 31,.6 25 .8 25 .3 24 .7 21 .4 19 .0 18 . 7

4 S 38 . 5 57,.8 64 .2 70 .7 87 .3 104 .6 108 .6 124 .9 R 38,.5 37,.4 30 .4 26 .0 25 .4 24 .8 22 .0 21 .5

5 S 44,.8 67,.5 74,.6 81 .8 101,.0 121,.0 125,.0 144,.0

R 44,.8 43.,5 35,.0 29,.8 29,.0 28,.3 25,.0 24,.4

6 S 51..0 77,,0 84..9 92,.7 114,,4 137,.2 141,. 1 162,.6 R 51..0 49,,3 39,,5 33.,4 32,,5 31,.6 27,.8 27,,0

8 S 62..1 76,,4 103,,6 112,.8 139..2 146,.2 153,, 1 176.,4

R 62..1 49.,2 47.,7 40,,0 38,.8 33.,8 30.,2 29.,4

10 S 73.,6 90. 6 104.,2 133,,6 144.,0 172.,6 180,,1 207.,7

R 73.,6 58. 0 48. 3 46.,7 40,,4 39. 2 34. 8 33. 7

12 S 84.,0 103. 6 119. 1 152. 8 164. 3 197. 1 204. 8 236. 3 R 84. 0 66. 0 54. 8 52. 8 45. 6 44. 0 38. 8 37. 4

14 S 90. 3 111. 7 128. 6 165. 0 176. 5 211. 7 219. 7 253. 7 R 90. 3 70. 8 58. 8 56. 6 48. 3 46 . 5 40. 9 39. 3

16 S 100. 9 123. 9 142. 0 158. 4 195. 5 208. 2 243. 3 253. 6 R 100. 9 95. 5 64. 1 54. 6 52. 5 45. 9 44. 2 39. 4

18 S 108. 8 135. 3 155. 5 173. 5 214. 2 228. 0 266. 6 277. 8 R 108. 8 84; 5

• 69. 4 59. 0 56. 5 49. 3 47. 2 42. 1

Note: Energy Cost = $3.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-l.b

Note

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $3/MBtu

Pipe Process Fluid Temperature (F)

Size

inch) 150 200 250 300 350 400 450 500

1 1.0 1.5 1.5 1.5 1.5 1.5 1.5 1.5

2 1.5 1.5 1.5 2.0 2.0 2.5 2.5 2.5

3 1.5 1.5 2.0 2.0 2.0 2.5 3.0 3.0

4 1.5 1.5 2.0 2.5 2.5 2.5 3.0 3.0

5 1.5 1.5 2.0 2.5 2.5 2.5 3.0 3.0

6 1.5 1.5 2.0 2.5 2.5 2.5 3.0 3.0

8 1.5 2.0 CM o 2.5 2.5 3.0 3.5 3.5

10 1-.5 2.0 . 2.5 2.5 3.0 3.0 3.5 3.5

12 1.5 2.0 2.5 2.5 3.0 3.0 3.5 3.5

14 1.5 2.0 2.5 2.5 3.0 3.0 3.5 3.5

16 1.5 CM o 2.5 3.0 3.0 3.5 3.5 4.0

18 1.5 2.0 2.5 3.0 3.0 3.5 3.5 4.0

Energy Cost = $3.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 2.

Maximum Allowable Heat Losses (Btu/h'ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $4/M Btu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Type 150 • 200 250 300 350 400 450 500

1 S 17 .6 26 .2 35 .3 45 .1 55 .6 57,.0 66. 7 76,.6 R 17 .6 17 .3 17 .1 16 .8 16,.5 14,.1 13. 9 13,.7

2 S 25 .0 37 .3 42,.2 54 .0 66 .6 70,.0 81. 8 94,.0

R 25 .0 24 .6 20 .4 20 .0 19 .6 17,.2 16. 9 16,.6

3 S 32 .3 40 .0 54 .1 69 .2 85 .3 88 .6 92. 6 106 .5 R 32 .3 26 .3 25 .8 25 .3 24 .7 21 .4 19. 0 18 .7

4 S 38 .5 47 .4 55 .3 70 .7 87 .3 104 .6 108. 6 124 ..9 R 38 .5 31 .1 26 .5 26 .0 25 .4 24 .8 22. 0 21 .5

5 S 44 .8 55 .1 64 .0 81 .8 101 .0 121 .0 125. 0 144 .0

R 44 .8 35 .9 30 .4 29 .8 29 .0 28 .3 25. 0 24 .4

6 S 51 .0 62 .6 72 .4 92 .7 114 .4 137 .2 141. 1 146 .4

R 51 .0 40 .7 34,.3 33 .4 32 .5 . 31 .6 27. 8 25 .0

8 S 50 .7 76 .4 88 .0 112 .8 122 .0 146 .2 153. 1 176 .4

R 50 .7 49 .2 41,.2 40 .0 34 .8 33 .8 30. 2 29 .4

10 S 59,.9 90 .6 104,.2 133 .6 144,.0 154 .1 180. 1 188 .5 R 59 .9 58,.0 48,.3 46 .7 40,.4 35,.8 34. 8 31,.5

12 S 68,.4 103,,4 119,,1 133,.2 146,.2 175,,3 185. 3 213,.7 R 68,,4 66

.0 54,,8 47,.1 41,.4 40,,0 35. 8 34,,7

14 S 73,,6 111.,7 128.,6 143,.0 156. 8 188.,0 198. 6 229. 2 R 73.,6 70..,8 58. 8 50.,1 43. 8 42. 4 37. 8 36. 5

16 S 81. 4 104. 5 123. 4 158. 4 173. 6 188. 0 219. 7 231

9 R 81. 4 66

6 56. 6 54. 6 47. 7 42. 4 40. 9 37. 0

18 S 88. 6 114. 2 135. 1 154. 0 190. 1 205. 7 240. 5 253. 7 R 88. 6 72. 4 61. 4 53. 4 51. 4 45. 6 43.9 39. 6

Note: Energy Cost = $4.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-2.b

Economic Insulation Thickness ( inch) for Hot VJater Supply

and Return Pipes for Energy Cost of $4/KBtu

Pipe Process Fluid Temnerature (F)

Size

( inch) 200 250 300 350 4flfi 500

1 1 .5 1 .5 1 .5 1 .5 1 .5 2 .0 2.0 2.0

2 1 .5 1 .5 2.0 2.0 2.0 2'.5 2.5 2.5

3 1 .5 2.0 2.0 2.0 2.0 2.5 3 .0 3 .0

4 1 .5 2.0 2.5 2.5 2.5 2.5 3 .0 3 .0

5 1 .5 2.0 2.5 2.5 2.5 2.5 3.0 3 .0

6 1.5 2.0 2.5 2.5 2.5 2.5 3 .0 3 .5

8 2.0 2.0 2.5 2.5 3.0 3.0 3.5 3.5

10 2 .0 2.0 2.5 2.5 3.0 3.5 3.5 4.0

12 2.0 2.0 2.5 3 .0 3.5 3.5 4.0 4.0

14 2.0 2.0 2.5 3 .0 3.5 3.5 4.0 4.0

16 2.0 2.5 3.0 3 .0 3.5 4.0 4.0 4.5

18 2.0 2.5 3 .0 3.5 3.5 4.0 4.0 4.5

Note: Energy Cost = $4.00/MEtu

Return Pipe Temperature = 150 F
TABLE A- 3.

a

Maximum Allowable Heat Losses (Btu/h-ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $5/M Btu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Tvne 150 200 250 300 350 400 450 500

1 S 17,.6 26,.2 35 .3 38,.6 47,.6 57,.0 66.,7 68,.4

R 17,. 6 17,.3 17,.1 14,.5 14,.3 14,,1 13,,9 12,.4

2 S 25,,0 37,.3 42,,2 47..4 58,.4 70,,0 81

,

.8 84,.9 R 25,,0 24,,6 20.,4 17,.7 17..5 17,,2 16..9 15,,2

3 S 26,,8 40,,0 54,,1 60.,0 74,.0 79,,3 92,,6 106,,5

R 26,,8 26,,3 25..8 22.,2 21.,8 19,,4 19.,0 18,.7

4 S 31.,7 47.,4 55,,3 70.,7 87.,3 92.,9 108. 6 124.,9

R 31.,7 31. 1 26.,5 26.,0 25.,4 22,,5 22. 0 21

.

,5

5 S 36.,8 55. 1 64.,0 81.,8 101.,0 107.,0 125. 0 144.,0

R 36.,8 35. 9 30.,4 29.,8 29. 0 25.,6 25. 0 24.,4

6 S 41. 7 62.,6 72.,4 92.,7 114.,4 120.,8 127. 1 146. 4

R 41.,7 40. 7 34.,3 33.,4 32.,5 28.,5 25. 6 25, 0

8 S 50.,7 76. 4 77.,2 98.,8 122.,0 131.,0 139. 5 160.,7

R 50.,7 49. 2 36.,6 35.,7 34,,8 30.,9 28. 0 27,,4

10 S 59.,9 76.,8 91.,1 116.,7 128..6 154..1 163. 6 173,.1 R 59.,9 49 .,7 42.,8 41.,7 36,,8 35.,8 32. 3 29,,4

12 S 68,,4 87.,8 103.,9 118.,5 146.,2 158.,6 185. 3 195,,8

R 68,,4 56.,6 48,,5 42.,5 41.,3 36.,8 35. 8 32.,4

14 S 73.,6 94.,7 111.,5 127.,1 156.,8 170.,0 198. 6 209.,8

R 73,,6 60. 8 51,,7 45. 2 43, 8 39.,0 37. 8 34.,2

16 S 81.,4 90. 9 109.,7 140. 6 156. 8 172. 0 201. 0 231.,9

R 81.,4 58. 5 50.,9 49. 3 43. 8 39. 4 38. 2 37. 0

18 S 88. 6 99. 4 120.,0 154. 0 171. 5 188. 1 219. 8 234. 2 R 88.,6 63. 6 55. 3 53. 4 47. 3 42. 5 41. 1 37. 4

Note: Energy Cost = $5.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-3.b

Note

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $5/MBtu

Pipe Process Fluid Temnerature (F)

Size

f inch) 150 200 250 300 350 400 450 500

1 1.5 1.5 1.5 2.0 2.0 2.0 2.0 2.5

2 1.5 1.5 2.0 2.5 2.5 2.5 2.5 3.0

3 2.0 2.0 2.0 2.5 2.5 3.0 3.0 3.0

4 2.0 2.0 2.5 2.5 2.5 3.0 3.0 3.0

5 2.0 2.0 2.5 2.5 2.5 3.0 3.0 3.0

6 2.0 2.0 2.5 2.5 2.5 3.0 3.5 3.5

8 2.0 2.0 3.0 3.0 3.0 3.5 4.0 4.0

10 2.0 2.5 3.0 3.0 3.5 3.5 4.0 4.5

12 2.0 2.5 3.0 3.5 3.5 4.0 4.0 4.5

14 2.0 2.5 3.0 3.5 3.5 4.0 4.0 4.5

16 2.0 3.0 3.5 3.5 4.0 4.5 4.5 4.5

18 2.0 3.0 3.5 3.5 4.0 4.5 4.5 5.0

Energy Cost = $5.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-4.a

Maximum Allowable Heat Losses (Btu/h-ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $6/M Btu

Pipe Process Fluid Temperature ('F) Size Pipe

( inch) Type 150 200 250 300 350 400 450 500

1 S 17 .6 26 .2 35 .3 38 .6 47 . 6 51 .0 59 .6 68 .4

R 17 .6 17 .3 17 .1 14 .5 14 . 3 12 .7 12 .6 12 .4

2 S 25 .0 31 .3 37 . 1 47 .4 58 .4 63 .2 73 .9 84 .9

R 25 .0 20 .7 18 .0 17 .7 17 .5 15 .7 15 . 5 15 .2

3 S 26 .8 40 .0 46 .9 60 .0 66 .2 79 . 3 92 .6 106 .5 R 26 .8 26 .3 22 .6 22 .2 19 .7 19 .4 19 .0 18 .7

4 . S 31 .7 40 .9 55 .3 70 .7 77 .5 92 .9 108 .6 113 .4

R 31 .7 27 .0 26 .5 26 .0 22 .9 22 .5 22 .0 19 .9

5 S 36 .8 47 .3 64 .0 81 .8 89 .3 107 .0 125 .0 130 .0

R 36 .8 31 .1 30 .4 29 .8 26 .1 25 .6 25 .0 22 .5

6 S 41 .7 53 .5 72 .4 81 .7 100 .8 120 .8 127 . 1 146 .4

R 41 .7 35 .1 34 .3 29 .9 29 .2 28 .5 25 .6 25 .0

8 S 50,.7 65 .0 77 .2 88 .6 109 .3 131 .0 139 .5 160 .7

R 50,.7 42 .3 36,.6 32 .4 31 .7 30 .9 28 .0 27 .4

10 S 51..1 76,.8 91,.1 104,.2 128,.6 140 .0 150,.3 173 . 1 R 51,.1 49,.7 42,.8 37,.8 36,.8 33,. 1 30,. 1 29 .4

12 S 58,.2 76,.7 92.,5 118,,5 132,.3 158,,6 169..9 181

,

.3 R 58.,2 49.,8 43.,6 42..5 37..8 36,,8 33,.3 30,,5

14 S 62. 7 82.,2 99. 2 127., 1 141.,8 170. 0 181.,9 194,,1

R 62. 7 53. 2 46. 4 45. 2 40. 2 39. 0 35. 3 32. 2

16 S 69. 0 90. 9 109. 7 127. 0 143. 5 172. 0 201

.

0 214. 3 R 69. 0 58. 5 50. 9 45. 1 40. 6 39. 4 38. 2 34. 8

18 S 75. 2 99. 4 120. 0 139. 0 156. 8 173. 7 203. 0 218. 0

R 75. 2 63. 6 55. 3 48. 9 43. 9 39. 9 38. 7 . 35. 4

Note: Energy Cost = $6.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-4.b

Note

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $6/NBtu

Pipe Process Fluid Temnerature: (F)

Size

' inch) 150 200 250 300 350 400 450 500

1 1.5 1.5 1.5 2.0 2.0 2.5 2.5 2.5

2 1.5 2.0 2.5 2.5 2.5 3.0 3.0 3.0

3 2.0 2.0 2.5 2.5 3.0 3.0 3.0 3.0

4 2.0 2.5 2.5 2.5 3.0 3.0 3.0 3.5

5 2.0 2.5 . 2.5 2.5 3.0 3.0 3.0 3.5

6 2.0 2.5 2.5 3.0 3.0 3.0 3.5 3.5

8 2.0 2.5 3.0 3.5 3.5 3.5 4.0 4.0

10 -2.5 2.5 3.0 3.5 3.5 4.0 4.5 4.5

12 2.5 3.0 3.5 3.5 4.0 4.0 4.5 5.0

14 2.5 3.0 3.5 3.5 4.0 4.0 4.5 5.0

16 2.5 3.0 3.5 4.0 4.5 4.5 4.5 5.0

18 2.5 3.0 3.5 4.0 4.5 5.0 5.0 5.5

Energy Cost = $6.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 5.

a

Maximum Allowable Heat Losses (Btu/h-ft) from the SupplyPipe (S) and the Return Pipe (R) for Energy Cost of $7/M Btu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch") Type 150 200 250 300 350 400 450 500

1 S 17,.6 26 .2 30.2 38 .6 47 .6 51 .0 59,.6 62.7

R 17,,6 17 .3 14.7 14,,5 14,.3 12,.7 12,.6 11.5

2 S 21.,0 31,.3 37.1 47,,4 58,,4 63 .2 73,,9 ' 84.9

R 21,,0 20,.7 18.0 17,.7 17,.5 15,.7 15,,5 15.2

3 s 26.,8 40,.0 46.9 53.,6 66,.2 79,.3 92,,6 106.5

R 26.,8 26,,3 22.6 20,, 1 19,,7 19,.4 19,.0 18.7

4 S 27. 4 40,.9 55.3 62.,9 77,. 5 92,.9 98 ,.6 113.4

R 27.,4 27,,0 26.5 23..3 22,,9 22,.5 20,.3 19.9

5 S 31.,7 47,.3 64.0 72.,4 89,,3 107,.0 113,.0 130.0

R 31.,7 31,.1 30.4 26.,7 26,.1 25,.6 23,,0 22.5

6 S 35. 8 53,.5 72.4 81.,7 100,,8 108,.8 116,.4 133.9

R 35.,8 35,,1 34.3 29.,9 .29,,2 26,,1 23,,8 23.3

8 S 43.,3 65..0 77.2 88,,6 109,,3 119,.4 128,.8 148.2

R 43. 3 42,.3 36.6 32.,4 31

,

,7 28,.6 26,,2 25.7

10 S 44.,9 67,,2 81.4 104..2 116,,8 128,,6 150,.3 160.6

R 44.,9 43,,9 38.6 37.,8 33,,9 30,,8 30,. 1 27.6

12 S 51.,1 68,,3 83.7 107.,2 132,.3 145,,4 157,.4 169.3

R 51.,1 44,,6 39.7 38.,8 37,,8 34,,2 31.,3 28.8

14 S 54. 7 73,.2 89.7 114. 9 141.,8 155,.7 168.,4 181 .

1

R 54, 7 47,,7 42.3 41. 3 40,,2 36..2 33. 1 30.5

16 S 60. 3 80,,9 99.1 116. 3 143. 5 172. 0 185. 8 199.7

R 60. 3 52.,4 46.4 41. 7 40. 6 39. 4 35. 9 33.0

18 S 65. 8 88. 4 108.4 127. 1 144. 9 173. 7 189. 0 218.0

R 65. 8 57. 0 50.4 45. 2 41. 0 39. 9 36. 6 35.4

Note: Energy Cost = $7.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-5.b

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $7/MBtu

Pipe Process Fluid Temterature (F)

Size

( inch) 150 200 250 300 350 400 450 500

1 1.5 1.5 2.0 2.0 2.0 2.5 2.5 3.0

2 2.0 2.0 2.5 2.5 2.5 3.0 3.0 3.0

3 2.0 2.0 2.5 3.0 3.0 3.0 3,0 3.0

4 2.5 2.5 2.5 3.0 3.0 3.0 3.5 3.5

5 2.5 2.5 2.5 3.0 3.0 3.0 3.5 3.5

6 2.5 2.5 2.5 3.0 3.0 3.5 4.0 4.0

8 2.5 2.5 3.0 3.5 3.5 4.0 4,5 4.5

10 -3.0 3.0 3.5 3.5 4.0 4.5 4.5 5.0

12 3.0 3.5 4.0 4.0 4.0 4.5 5.0 5.5

14 3.0 3.5 4.0 4.0 4.0 4.5 5.0 5.5

16 3.0 3.5 4.0 4.5 4.5 4.5 5.0 5.5

18 3.0 3.5 4.0 4.5 5.0 5.0 5.5 5.5

Note: Energy Cost = $7.00/KBtu

Return Pipe Temperature = 150 F
TABLE A-6 .

a

Maximum Allowable Heat Losses (Btu/h'ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $8/M Btu

Pipe , Process Fluid Temperature (F)

Size Pipe

( inch') Type 150 200 250 300 350 400 450 500

1 S 17,.6 22,.4 30,.2 34,.5 42 .5 51,.0 59,.6 62 .7 R 17,.6 14,.9 14,.7 13,.1 12 .9 12,.7 12,.6 11 .5

2 S 18,,5 27,.5 37,.1 42,.8 52 .8 63 .2 73 .9 84 .9

R 18,.5 18 .3 18,.0 16,.1 15 .9 15 .7 15 .5 15 .2

3 S 23,.3 34,.8 42,.0 53 .6 66 .2 79 .3 92 .6 106 .5

R 23,.3 23 .0 20,.4 20 . 1 19 .7 19 .4 19 .0 18 .7

4 S 27,.4 40 .9 49 .2 62 .9 70 .4 84 .4 98 .6 113 .4

R 27,.4 27 .0 23,.7 23 .3 21 .0 20 .7 20 .3 19 .9

5 S 31,.7 47 .3 56,.6 72 .4 80 .7 96 .7 113 .0 119 .4

R 31,.7 31 .1 27,.2 26 .7 23 .9 23 .4 23 .0 21 .0

6 S 35,.8 53 .5 63,,9 73 .6 90 .8 108 .8 116 .4 133 .9

R 35,.8 35 .1 30,.5 27 .2 26 .7 26 :1 23 .8 23 .3

8 S 43,.3 57,.1 69,.3 80 .8 99 .6 119 .4 128 .8 148 .2

R 43,.3 37,.4 33,.1 29,.8 29 .2 28 .6 26 .2 25 .7

10 S 44,.9 67,.2 81,.4 94,,7 107,.3 128 .6 150 . 3 160 .6

R 44.,9 43,,9 38,.6 34,.7 31,.4 30,.8 30,.1 27 .6

12 S 51,,1 68,,3 83,,7 107,,2 121,,3 134,.7 157.,4 169 .3 R 51.,1 44,.6 39,,7 38,,8 35,,0 32,.0 31,,3 28,,8

14 S 54. 7 73.,2 89. 7 114. 9 129.,9 144., 1 157.,2 181., 1 R 54. 7 47.,7 42. 3 41. 3 37.,2 33. 9 31. 3 30.,5

16 S 53. 8 73. 1 90. 8 116. 3 132. 6 159. 0 173. 2 199. 7 R 53. 8 47. 6 42. 8 41. 7 38. 0 37. 0 34. 0 33. 0

18 S 58. 7 79. 9 99. 2 127. 1 134. 9 161. 8 189. 0 218. 0

R 58. 7 51. 8 46. 5 45. 2 38. 6 37. 6 36. 6 35. 4

Note: Energy Cost = $8.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-6.b

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $8/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

1 1.5 2.0 2.0 2.5 2.5 2.5 2.5 3.0

2 2.5 2.5 2.5 3.0 3.0 3.0 3.0 3.0

3 2.5 2.5 3.0 3.0 3.0 3.0 3.0 3.0

4 2.5 2.5 3.0 3.0 3.5 3.5 3.5 3.5

5 2.5 2.5 3.0 3.0 3.5 3.5 3.5 4.0

6 2.5 2.5 3.0 3.5 3.5 3.5 4.0 4.0

8 2.5 3.0 3.5 4.0 4.0 4.0 4.5 4.5

10 '3.0 3.0 3.5 4.0 4.5 4.5 4.5 5.0

12 3.0 3.5 4.0 4.0 4.5 5.0 5.0 5.5

14 3.0 3.5 4.0 4.0 4.5 5.0 5.5 5.5

16 3.5 4.0 4.5 4.5 5.0 5.0 5.5 5.5

18 3.5 4.0 4.5 4.5 5.5 5.5 5.5 5.5

Note: Energy Cost = $8.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 7.

a

Maximum Allowable Heat Losses (Btu/h‘ft) from the SupplyPipe (S) and the Return Pipe (R) for Energy Cost of $9/M Btu

Pipe

Size

( inch")

Pipe

Type 150

1 S 17.6

R 17.6

2 S 18.5

R 18.5

3 S 23.3

R 23.3

4 S 27.4

R 27.4

5 S 31.7

R 31.7

6 S 35.8

R 35.8

8 S 43.3

R 43.3

10 S 44.9

R 44.9

12 S 51.1

R 51.1

14 S 54.7

R 54.7

16 S 53.8

R 53.8

18 S 58.7

R 58.7

Process Fluid

200 250 300

22 .4 30 .2 34 .5

14 .9 14 .7 13 .1

27 .5 37 . 1 42 .8

18 .3 18 .0 16 . 1

34 .8 42 .0 53 .6

23 .0 20 .4 20 . 1

40 .9 49 .2 62 .9

27,.0 23 .7 23 .3

47,.3 56,.6 72 .4

31,.1 27,.2 26,.7

53..5 63,,9 73,.6 35,,1 30,,5 27,.2

57.,1 69,,3 80,,8

37.,4 33,,1 29,,8

60. 2 74. 0 94.,7

39. 5 35. 4 34. 7

68. 3 83. 7 98. 3 44. 6 39. 7 35. 9

73. 2 89. 7 105. 3 47. 7 42. 3 38. 2

73. 1 90. 8 116. 3 47. 6 42. 8 41

.

7

79. 9 99. 2 117. 4

51. 8 46. 5 42. 2

Temperature (F)

350 400 450

42 .5 46 .7 54 .6

12 .9 11 .8 11 .6

52 .8 63 .2 73 .9

15 .9 15 .7 15 .5

66 .2 79 .3 84 .6

19 .7 19 .4 17 . 6

70 .4 84 .4 98 .6

21 .0 20 .7 20 .3

30 .7 96 .7 103 .8

23 .9 23 .4 21 .4

90,.8 108,.8 116,.4

26,.7 26,.1 23,,8

99,,6 no..2 128,.8 29,,2 26,.7 26,,2

107.,3 128,,6 139.,5

31

.

,4 30,,8 28, 2

112. 4 134. 7 147. 1 32. 7 32. 0 29. 5

120. 2 134. 5 157. 2 34. 8 32. 0 31. 3

132. 6 148. 2 173. 2 38. 0 34. 8 34. 0

134. 9 161. 8 189. 0

38. 6 37. 6 36. 6

500

62.7

11.5

84.9

15.2

97.2

17.3

113.4

19.9

119.4

21.0

124.1

21.9

138.1

24.3

150.3

26.1

169.3

28.8

170.2

29.0

187.4

31.4

218.0

35.4

Note: Energy Cost = $9.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-7.b

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $9/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

1 1.5 2.0 2.0 2.5 2.5 3.0 3.0 3.0

2 2.5 2.5 2.5 3.0 3.0 3.0 3.0 3.0

3 2.5 2.5 3.0 3.0 3.0 3.0 3.5 3.5

4 2.5 2.5 3.0 3.0 3.5 3.5 3.5 3.5

5 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.0

6 2.5 2.5 3.0 3.5 3.5 3.5 4.0 4.5

8 2.5 3.0 3.5 4.0 4.0 4.5 4.5 5.0

10 -3.0 3.5 4.0 4.0 4.5 4.5 5.0 5.5

12 3.0 3.5 4.0 4.5 5.0 5.0 5.5 5.5

14 3.0 3.5 4.0 4.5 5.0 5.5 5.5 6.0

16 3.5 4.0 4.5 4.5 5.0 5.5 5.5 6.0

18 3.5 4.0 4.5 5.0 5.5 5.5 5.5 6.0

Note: Energy Cost = $9.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-8 .

a

Maximum Allowable Heat Losses (Btu/h-ft) from the SupplyPipe (S) and the Return Pipe (R) for Energy Cost of $10/M Btu

P^ipe Process Fluid Temperature (T)

Size Pipe

( inch) Type 150 200 250 300 350 400 450 500

1 S 17,.6 22.,4 27 .0 34.5 39,.0 46.,7 54,,6 62.7

R 17,,6 14,.9 13,.2 13.1 11,,9 11,,8 11.,6 11.5

2 S 18,,5 27,,5 37,.1 42.8 52,,8 63..2 73,,9 84.9

R 18,,5 18,,3 18,.0 16.1 15.,9 15,.7 15,, 5 15.2

3 S 23,,3 34.,8 42,.0 53.6 66,.2 79,,3 84.,6 97.2

R 23,,3 23,,0 20.,4 20.1 19.,7 19,.4 17,,6 17.3

4 S 27.,4 40.,9 49..2 57.1 70.,4 84.,4 98.,6 113.4

R 27.,4 27.,0 23,,7 21.4 21..0 20..7 20.,3 19.9

5 S 31.,7 47.,3 56,.6 65.4 80.,7 88,,8 103.,8 119.4

R 31.,7 31.,1 27,.2 24.3 23,,9 21.,8 21,,4 21.0

6 S 35.,8 47..2 57,,6 73.6 90,,8 99..6 107,,9 124.1

R 35. 8 31,.1 27,.7 27.2 26.,7 24,,2 22..3 21.9

8 S 38.,2 51,,2 63..2 74.6 92,,0 110,.2 120.,1 138.1

R 38.,2 33.,7 30..4 27.7 27..3 26,.7 24..7 24.3

10 S 44.,9 60,,2 74,,0 87.0 99,.6 119,,4 130,,6 150.3

R 44.,9 39.,5 35,.4 32.1 29.,4 28,,8 26,.6 26.1

12 S 45. 6 61.,9 76,,8 98.3 112.,4 125.,8 147.,1 159.3

R 45. 6 40.,6 36.,6 35.9 32.,7 30,,2 29.,5 27.4

14 S 48. 8 66.,3 82,.2 105.3 120. 2 134. 5 157.,2 170.2

R 48. 8 43. 3 39.,0 38.2 34.,8 32. 0 31. 3 29.0

16 S 53. 8 73. 1 90. 8 116.3 132. 6 148. 2 162. 6 187.4

R 53. 8 47. 6 42. 8 41.7 38. 0 34. 8 32. 2 31.4

18 S 58. 7 73. 2 91. 6 117.4 134. 9 161

.

8 177. 3 204.4

R 58. 7 47. 7 43. 2 42.2 38. 6 37. 6 34. 7 33.7

Note: Energy Cost = $10.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-8.b

Note

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $10/NBtu

Pipe Process Fluid Temnerature (F)

Size

' inch) 150 200 250 300 350 400 450 500

1 1.5 2.0 2.5 2.5 3.0 3.0 3.0 3.0

2 2.5 2.5 2.5 3.0 3.0 3.0 3.0 3.0

3 2.5 2.5 3.0 3.0 3.0 3.0 3.5 3.5

4 2.5 2.5 3.0 3.5 3.5 3.5 3.5 3.5

5 2.5 2.5 3.0 3.5 3.5 4.0 4.0 4.0

6 2.5 3.0 3.5 3.5 3.5 4.0 4.5 4.5

8 3.0 3.5 4.0 4.5 4.5 4.5 5.0 5.0

10 3.0 3.5 4.0 4.5 5.0 5.0 5.5 5.5

12 3.5 4.0 4.5 4.5 5.0 5.5 5.5 6.0

14 3.5 4.0 4.5 4.5 5.0 5.5 5.5 6.0

16 3.5 4.0 4.5 4.5 5.0 5.5 6.0 6.0

18 3.5 4.5 5.0 5.0 5.5 5.5 6.0 6.0

Energy Cost = $10.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 9.

a

Maximum Allowable Heat Losses (Btu/h'ft) from the SupplyPipe (S) and the Return Pipe (R) for Energy Cost of $11/M Btu

Pipe Process Fluid Temperature ('F') Size Pipe

( inch) Type 150 200 250 300 350 400 450 500

1 S 15 .1 22 .4 27 .0 34.5 39 .0 46 .7 54 .6 62 .7

R 15 .1 14 .9 13 .2 13.1 11 .9 11 .8 11 .6, 11 .5

2 S 18 .5 27 .5 33 .5 42.8 52 .8 63 .2 73 .9 78 .2

R 18 .5 18 .3 16 .4 16.1 15 .9 15 .7 15 .5 14 .2

3 S 23 .3 34 .8 42 .0 53.6 66 .2 79 ..3 84 .6 97 .2

R 23 .3 23 .0 20 .4 20.1 19 .7 19 .4 17 .6 17 .3

4 S 27 .4 40 .9 44 .7 57.1 70 .4 84 .4 98 .6 113 .4

R 27 .4 27 .0 21 .7 21.4 21 .0 20 .7 20 .3 19 .9

5 S 31 .7 41 .9 51 .2 65.4 74 .1 88 .8 103 .8 119 .4

R 31 .7 27,.7 24 .7 24.3 22 .2 21 .8 21 .4 21 .0

6 S 35 .8 47,.2 57 .6 73.6 83 . 1 99 .6 107 .9 124 .1 R 35 .8 31,.1 27 .7 27.2 24 .7 24 .2 22 .3 21 .9

8 S 38,.2 51,.2 63 .2 74.6 92 .0 102 .7 120 .1 129 .6

R 38,.2 33..7 30,.4 27.7 27,.3 25 .2 24,.7 23 .0

10 S 44,.9 60.,2 74,.0 87.0 99,.6 111,.8 130,.6 141,.6 R 44,.9 39,,5 35.,4 32.1 29,,4 27,,1 26,.6 24,,8

12 S 45..6 61. 9 76,,8 91.1 105,,0 125.,8 138.,4 159,.3 R 45.,6 40. 6 36.,6 33.4 30.,8 30.,2 28.,0 27.,4

14 S 48.,8 66. 3 82. 2 97.4 112. 2 134. 5 147. 8 170. 2 R 48. 8 43. 3 39. 0 35.6 32. 7 32. 0 29. 7 29. 0

16 S 48. 7 67. 0 84. 0 107.5 123. 7 139. 2 162. 6 187. 4

R 48. 7 43. 8 39. 8 38.9 35. 7 33. 0 32. 2 31. 4

18 S 53. 2 73. 2 85. 4 109.3 134. 9

' 151. 7 177. 3 204. 4

R 53. 2 47. 7 40. 5 39.6 38. 6 35. 6 34. 7 33. 7

Note: Energy Cost = $11.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-9.b

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $ll/MBtu

Pipe Process Fluid Temnerature: (F)

Size

( inch) 150 200 250 300 350 400 450 500

1 2.0 2.0 2.5 2.5 3.0 3.0 3.0 3.0

2 2.5 2.5 3.0 3.0 3.0 3.0 • 3.0 3.5

3 2.5 2.5 3.0 3.0 3.0 3.0 3.5 3.5

4 2.5 2.5 3.5 3.5 3.5 3.5 3.5 3.5

5 2.5 3.0 3.5 3.5 4.0 4.0 4.0 4.0

6 2.5 3.0 3.5 3.5 4.0 4.0 4.5 4.5

8 3.0 3.5 4.0 4.5 4.5 5.0 5.0 5.5

10 -3.0 3.5 4.0 4.5 5.0 5.5 5.5 6.0

12 3.5 4.0 4.5 5.0 5.5 5.5 6.0 • 6.0

14 3.5 4.0 4.5 5.0 5.5 5.5 6.0 6.0

16 4.0 4.5 5.0 5.0 5.5 6.0 6.0 6.0

18 4.0 4.5 5.5 5.5 5.5 6.0 6.0 6.0

Note; Energy Cost = $11.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 10.

a

Maximum Allowable Heat Losses (Btu/h-ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $12/M Btu

Pipe Process Fluid Temne:trature (F)

Size Pipe

( inch') Typ.e 150 200 250 300 350 400 450 500

1 s 15 .1 20 . 1 27.0 31 .6 39 .0 46 .7 54 .6 62 .7

R 15 .1 13 .4 13.2 12 .1 11 .9 11 .8 11 .6 11 .5

2 S 18 .5 27 .5 33.5 42 .8 52 .8 63 .2 68 .1 78 .2

R 18 .5 18 .3 16.4 16 .1 15 .9 15 .7 14 .4 14 .2

3 S 23 .3 31 .1 42.0 53 .6 66 .2 72 .4 84 .6 90 . 1 R 23 .3 20 .7 20.4 20 .1 19 .7 17 .4 17,.6 16 .2

4 S 27.,4 36,.4 44.7 57,. 1 70 .4 84,.4 98,,6 104 .5 R 27,.4 24,.1 21.7 21,.4 21,.0 20,.7 20,.3 18 .6

5 S 31,,7 41,.9 51.2 65,,4 74,.1 88,,8 103..8 119,.4

R 31.,7 27,.7 24.7 24.,3 22..2 21,,8 21.,4 21,.0

6 S 35.,8 47,,2 57.6 67,,4 83,.1 92.,3 107.,9 116,.0 R 35.,8 31.,1 27.7 25.,1 24..7 22.,7 22.,3 20..7

8 S 38. 2 51.,2 63.2 74..6 92,,0 102.,7 120.,1 129..6 R 38. 2 33.,7 30.4 27.,7 27.,3 25.,2 24.,7 23.,0

10 S 40.,3 54.,8 68.0 80.,8 99.,6 111.,8 130. 6 141

.

.6 R 40..3 36.,1 32.7 29.,9 29.,4 27., 1 26. 6 24,.8

12 S 41.,1 56.,8 71.2 91.,1 105.,0 118.,4 138. 4 159,,3

R 41. 1 37.,3 34.1 33.,4 30.,8 28. 6 28. 0 27,,4

14 S 44. 2 60.,8 76.1 97. 4 112. 2 126. 4 147. 8 170.,2

R 44. 2 39.,9 36.3 35. 6 32. 7 30. 3 29. 7 29.,0

16 S 48. 7 67. 0 84.0 100. 2 123. 7 139. 2 162. 6 187. 4

R 48. 7 43.,8 39.8 36. 5 35. 7 33. 0 32. 2 31. 4

18 S 53. 2 67. 7 85.4 109. 3 134. 9 151. 7 177. 3 204. 4

R 53. 2 44. 2 40.5 39. 6 38. 6 35. 6 34. 7 33. 7

Note; Energy Cost = $12.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-lO.b

Note

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $12/MBtu

Pipe Process Fluid Teraoerature: (F)

Size

f inch) 150 200 250 300 350 400 450 500

1 2.0 2.5 2.5 3.0 3.0 3.0 3.0 3.0

2 2.5 2.5 3.0 3.0 3.0 3.0 3.5 3.5

3 2.5 3.0 3.0 3.0 3.0 3.5 3.5 4.0

4 2.5 3.0 3.5 3.5 3.5 3.5 3.5 4.0

5 2.5 3.0 3.5 3.5 4.0 4.0 4.0 4.0

6 2.5 3.0 3.5 4.0 4.0 4.5 4.5 5.0

8 3.0 3.5 4.0 4.5 4.5 5.0 5.0 5.5

10 '3.5 4.0 4.5 5.0 5.0 5.5 5.5 6.0

12 4.0 4.5 • 5.0 5.0 5.5 6.0 6.0 6.0

14 4.0 4.5 5.0 5.0 5.5 6.0 6.0 6.0

16 4.0 4.5 5.0 5.5 5.5 6.0 6.0 6.0

18 4.5 5.0 5.5 5.5 5.5 6.0 6.0 6.0

Energy Cost = $12.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 11 .a

Maximum Allowable Heat Losses (Btu/h-ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $13/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch') Type 150 200 250 300 350 40CI 450 500

1 S 15.,1 20. 1 24.8 31. 6 39. 0 46. 7 54. 6 62.7

R 15. 1 13. 4 12.2 12. 1 11. 9 11. 8 11. 6 11.5

2 S 18. 5 24. 9 33.5 42. 8 52. 8 58. 2 68. 1 78.2

R 18. 5 16. 6 16.4 16.,1 15. 9 14. 6 14. 4 14.2

3 S 20. 9 31. 1 42.0 53. 6 66. 2 72. 4 84. 6 90.1

R 20. 9 20. 7 20.4 20. 1 19. 7 17. 9 17. 6 16.2

4 S 24. 5 36. 4 44.7 57.,1 70. 4 84. 4 98.,6 104.5

R 24. 5 24. 1 21.7 21.,4 21.,0 20. 7 20.,3 18.6

5 S 28.,1 41. 9 51.2 60.,1 74..1 88. 8 103,.8 119.4

R 28.,1 27. 7 24.7 22.,5 22.,2 21. 8 21.,4 21.0

6 S 31.,7 42. 6 57.6 67.,4 77.,1 92. 3 107,,9 116.0

R 31.,7 28. 2 27.7 . 25.,1 23..1 22. 7 22.,3 20.7

8 S 38. 2 51. 2 63.2 74.,6 85.,7 102. 7 112..7 129.6

R 38.,2 33. 7 30.4 27.,7 25.,6 25. 2 23,,4 23.0

10 S 40. 3 54. 8 68.0 80. 8 93.,3 111. 8 123., 1 141.6

R 40.,3 36. 1 32.7 29. 9 27.,6 27. 1 25.,3 24.8

12 S 41. 4 56. 8 71.2 85. 1 105. 0 118. 4 138. 4 159.3

R 41. 4 37. 3 34.1 31. 4 30. 8 28. 6 28. 0 27.4

14 S 44. 2 60. 8 76.1 91. 0 105. 5 126. 4 147. 8 170.2

R 44. 2 39. 9 36.3 33. 4 30. 9 30. 3 29. 7 29.0

16 S 44. 7 62. 0 78.3 100. 2 116, 1 139. 2 162. 6 187.4

R 44. 7 40. 7 37.3 36. 5 33. 8 33.0 32. 2 31.4

18 S 48. 8 67. 7 85.4 109. 3 126. 6 151. 7 177. 3 204.4

R 48. 8 44. 2 40.5 39. 6 36. 5 35. 6 34. 7 33.7

Note: Energy Cost = $13.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-ll.b

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $13/MBtu

Pipe Process Fluid Temnerature (F)

Size

( inch) 150 200 250 300 350 400 450 500

1 2.0 2.5 3.0 3.0 3.0 3.0 3.0 3.0

2 2.5 3.0 3.0 3.0 3.0 3.5 3.5 3.5

3 3.0 3.0 3.0 3.0 3.0 3.5 3.5 4.0

4 _ 3.0 3.0 3.5 3.5 3.5 3.5 3.5 4.0

5 3.0 3.0 3.5 4.0 4.0 4.0 4.0 4.0

6 3.0 3.5 3.5 4.0 4.5 4.5 4.5 5.0

8 3.0 3.5 4.0 4.5 5.0 5.0 5.5 5.5

10 *3.5 4.0 4.5 5.0 5.5 5.5 6.0 6.0

12 4.0 4.5 5.0 5.5 5.5 6.0 6.0 6.0

14 4.0 4.5 5.0 5.5 6.0 6.0 6.0 6.0

16 4.5 5.0 5.5 5.5 6.0 6.0 6.0 6.0

18 4.5 5.0 5.5 5.5 6.0 6.0 6.0 6.0

Note: Energy Cost = $13.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 12.

a

Maximum Allowable Heat Losses (Btu/h'ft) from the SupplyPipe (S) and the Return Pipe (R) for Energy Cost of $14/MBtu

Pipe Process Fluid Tem-perature CF)

Size Pipe

( inch) Tvne 150 200 250 300 350 400 450 500

1 S 15 .1 20.1 24.8 31.6 39 .0 46 .7 54 .6 62 .7

R 15 .1 13.4 12.2 12.1 11 .9 11,.8 11 .6 11 .5

2 S 18 . 5 24.9 33.5 42.8 52 .8 58 .2 68 . 1 78 .2

R 18 .5 16.6 16.4 16.1 15 .9 14 .6 14 .4 14 .2

3 S 20 .9 31.1 42.0 53.6 60 .4 67 . 1 78 .4 90 . 1 R 20 .9 20.7 20.4 20.1 18 .2 16 .7 16 . 5 16 .2

4 S 24 .5 36.4 44.7 57.1 70 .4 77 ,8 90 .9 104 .5 R 24 .5 24.1 21.7 21.4 21 .0 19,.2 18 .9 18 .6

5 S 28 .1 41.9 51.2 60.1 74 .1 88,.8 103 .8 119 .4

R 28,.1 27.7 24.7 22.5 22 .2 21,.8 21 .4 21 .0

6 S 31,.7 42.6 52.7 62.5 77,.1 92,,3 107 .9 116 .0

R 31,.7 28.2 25.5 23.4 23,.1 22,,7 22,.3 20 .7

8 S 34,,3 46.8 58.3 69.5 85,.7 96.,4 112,.7 122,.4

R 34,,3 30.9 28.2 26.0 25,.6 23.,8 23,.4 21,.8

10 S 36.,7 50.4 63.2 75.6 93,.3 105. 3 123,. 1 141,.6 R 36.,7 33.2 30-.4 28.1 27.,6 25. 7 25,,3 24,,8

12 S 38. 0 52.7 66.5 85.1 98. 8 118. 4 138. 4 159.,3

R 38. 0 34.7 32.0 31.4 29. 1 28. 6 28. 0 27. 4

14 S 40. 6 56.3 71.1 91.0 105. 5 126. 4 147. 8 170. 2 R 40. 6 37.0 34.1 33.4 30. 9 30. 3 29. 7 29. 0

16 S 44. 7 62.0 00 94.1 116. 1 139. 2 162. 6 187. 4

R 44. 7 40.7 37.3 34.5 33. 8 33.0 32. 2 31. 4

18 S 48. 8 67.7 85.4 102.6 126. 6 151. 7 177. 3 204. 4

R 48. 8 44.2 40.5 37.3 • 36. 5 35. 6 34. 7 33. 7

Note: Energy Cost = $14.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-12.b

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $14/MBtu

Pipe Process Fluid Temnerature: (F)

Size

( inch) 150 200 250 300 350 400 450 500

1 2.0 2.5 3.0 3.0 3.0 3.0 3.0 3.0

2 2.5 3.0 3.0 3.0 3.0 3.5 3.5 3.5

3 3.0 3.0 3.0 3.0 3.5 4.0 4.0 4.0

4 3.0 3.0 3.5 3.5 3.5 4.0 4.0 4.0

5 3.0 3.0 3.5 4.0 4.0 4.0 4.0 4.0

6 3.0 3.5 4.0 4.5 4.5 4.5 4.5 5.0

8 3.5 4.0 4.5 5.0 5.0 5.5 5.5 6.0

10 -4.0 4.5 5.0 5.5 5.5 6.0 6.0 6.0

12 4.5 5.0 5.5 5.5 6.0 6.0 6.0 6.0

14 4.5 5.0 5.5 5.5 6.0 6.0 6.0 6.0

16 4.5 5.0 5.5 6.0 6.0 6.0 6.0 • 6.0

18 4.5 5.0 5.5 6.0 6.0 6.0 6.0 6.0

Note; Energy Cost = $14.00/MBtu

Return Pipe Temperature = 150 F
TABLE A- 13.

a

Maximum Allowable Heat Losses (Btu/h-ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $15/MBtu

Pipe Process Fluid Temnerature CF)

Size Pipe

( inch) Tvne 150 200 250 300 350 400 450 500

1 S 13 .5 20 .1 24.8 31 .6 39,.0 46. 7 54,.6 62.7

R 13,.5 13,.4 12.2 12 .1 11,.9 11. 8 11 .6 11.5

2 S 18,.5 24,.9 33.5 42 .8 48,.6 58. 2 68,, 1 78.2

R 18,.5 16,,6 16.4 16,.1 14,,8 14. 6 14,.4 14.2

3 S 20,,9 31,.1 42.0 53,,6 60.,4 67. 1 78.,4 90.1

R 20..9 20,,7 20.4 20,.1 18..2 16. 7 16,,5 16.2

4 S 24.,5 36.,4 44.7 57,.1 70.,4 77. 8 90,,9 104.5

R 24,,5 24..1 21.7 21,,4 21.,0 19. 2 18,,9 18.6

5 S 28.,1 41.,9 51.2 60,, 1 74.,1 88. 8 103..8 119.4

R 28.,1 27.,7 24.7 22,,5 22. 2 21. 8 21.,4 21.0

6 S 31.,7 42,,6 52.7 62,,5 77.,1 92. 3 107,,9 116.0

R 31.,7 28.. 2 25.5 23,.4 23.,,1 22. 7 22..3 20.7

8 S 34.,3 46. 8 58.3 69,.5 85.,7 96. 4 112,,7 122.4

R 34.,3 30. 9 28.2 26,,0 25,,6 23. 8 23.,4 21.8

10 S 36.,7 50.,4 63.2 75,,6 93.,3 105. 3 123,,1 141.6

R 36.,7 33.,2 30.4 28.,1 27.,6 25. 7 25,,3 24.8

12 S 38.,0 52.,7 66.5 85,,1 98.,8 118. 4 138,,4 159.3

R 38.,0 34.,7 32.0 31,,4 29.,1 28. 6 28,.0 27.4

14 S 40. 6 56. 3 71.1 91,,0 105. 5 126. 4 147.,8 170.2

R 40.,6 37. 0 34.1 33.,4 30. 9 30. 3 29.,7 29.0

16 S 44. 7 62. 0 78.3 94.,1 116. 1 139. 2 162. 6 187.4

R 44. 7 40. 7 37.3 34.,5 33. 8 33.01 32. 2 31.4

18 S 48. 8 67. 7 85.4 102. 6 126. 6 151. 7 177. 3 204.4

R 48. 8 44. 2 40.5 37. 3 36. 5 35. 6 34. 7 33.7

Note: Energy Cost = $15.00/MBtu

Return Pipe Temperature = 150 F
TABLE A-13.b

Note

Economic Insulation Thickness (inch) for Hot Water Supply

and Return Pipes for Energy Cost of $15/MBtu

Pipe Process Fluid Temnerature (F)

Size

' inch) 150 200 250 300 350 400 450 500

1 2.5 2.5 3.0 3.0 3.0 3.0 3.0 3.0

2 2.5 3.0 3.0 3.0 3.5 3.5 3.5 3.5

3 3.0 3.0 3.0 3.0 3.5 4.0 4.0 4.0

4 3.0 3.0 3.5 3.5 3.5 4.0 4.0 4.0

5 3.0 3.0 3.5 4.0 4.0 4.0 4.0 4.0

6 3.0 3.5 4.0 4.5 4.5 4.5 4.5 5.0

8 3.5 4.0 4.5 5.0 5.0 5.5 5.5 6.0

10 ^.0 4.5 5.0 5.5 5.5 6.0 6.0 6.0

12 4.5 5.0 5.5 5.5 6.0 6.0 6.0 6.0

14 4.5 5.0 5.5 5.5 6.0 6.0 6.0 6.0

16 4.5 5.0 5.5 6.0 6.0 6.0 6.0 6.0

18 4.5 5.0 5.5 6.0 6.0 6.0 6.0 6.0

Energy Cost = $15.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-1 .a

Maximum Allowable Heat Losses (Btu/h*ft) from the Supply

P ipe ( S) and the Return Pipe ( R) for Energy Cost of $3/MBtu

Pipe

Size

Process Fluid Temnerature (F)

Pipe

(inch) Type UO 200 250 300 350 400 450 500

2 S 25.3 37 .6 50.7 31 .6 64.8 95.7 93 .4 107 .4

1 R 17.4 17 .1 16 .7 16.4 16.0 15.6 13 .4 13.1

3 S 32.8 48.8 65.9 84.3 85.6 102.5 119.8 137.9

1 .5 R 21 .5 21 .0 20.4 19.8 16 .7 16.3 15.9 15.4

4 S 39.1 58.4 79.0 101 .0 101.7 104.8 122 .4 141 .0

2 R 24.5 23.9 23 .1 22.4 18.7 16 .4 16 .0 15.6

5 S 45.7 68.3 92.4 96.1 118.5 121 .4 141 .8 163 .3 2.5 R 27 .6 26.8 25.8 21 .4 20.7 18.1 17 .6 17 .0

6 S 52.1 78.0 105.6 109.4 134.8 137 .6 160.7 185 .2

3 R 31 .5 30.4 29.2 24.0 23.1 20 .1 19.4 18.7

8 S 63 .7 95.8 104.6 133.9 139.8 167 .5 195.6 225 .7 4 R 37.3 35.7 28.9 27 .8 23.8 23 .0 22.1 21.1

10 S 75.2 113 .6 124,1 134.3 165 .6 198.4 201 .2 233 .3 6 R 49.5 47 .2 37.8 31 .9 30 .7 29.4 25.9 24.9

12 S 86 .7 130.8 142.6 153 .9 189.8 227 .4 231 .1 266.8

6 R 48.9 46.3 37 .0 31 .2 29.8 28.4 25.1 23.9

14 S 92.7 113 .1 153 .5 165 .7 204.4 245 .0 248.8 254.9

8 R 60.0 47 .3 45.1 37 .8 36 .1 34.3 30 .1 26.8

16 S 104.6 126.5 171 .6 185.0 197 .4 236 .6 245 .0 282 .8

8 R 59.6 46.6 44.2 37 .0 31 .8 30.3 26.8 25.5

18 S 113.5 138.3 157 .7 202 .3 216.1 259.0 268.2 309.8

10 R 70.4 54.7 45.1 42.7 36.6 34.7 30.6 29.0

Note: Energy Cost = $3.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-l.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $3/MBtu

Pipe Process Fluid Temperature (F) ^ Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 1.5 1.5 1.5 1.5 1.5 1.5 2.0 2.0

3 & 1.5 1.5 1.5 1.5 1.5 2.0 2.0 2.0 2.0

4 & 2 1.5 1.5 1.5 1.5 2.0 2.5 2.5 2.5

5 5c 2.5 1.5 1.5 1.5 1.5 2.0 2.0 2.5 2.5

6 5c 3 1.5 1.5 1.5 2.0 2.0 2.5 2.5 2.5

8 5c 4 1.5 1.5 2.0 2.0 2.5 2.5 2.5 2.5

10 5c 6 1.5 1.5 2.0 2.5 2.5 2.5 3.0 3.0

12 5c 6 1.5 1.5 2.0 2.5 2.5 2.5 3.0 3.0

14 5c 8 1.5 2.0 2.0 2.5 2.5 2.5 3.0 3.5

16 5c 8 1.5 2.0 2.0 1.5 3.0 3.0 3.5 3.5

18 5c 10 1.5 2.0 2.5 2.5 3.0 3.0 3.5 3.5

Note: Energy Cost = $3.00/NBtu

Return Pipe Temperature = 150 F

i
TABLE B-2.a

Pipe

Size

(inch)

Maximum Allowable Heat Losses (Btu/h*ft) from the

Pipe ( S) and the Return Pipe ( R) for Energy Cost of

Process Fluid Temnerature (F)

Supp ly

$4/MBtu

P ipe

Type 200 250 300 350 400 450 500

2 S 25.3 37 .6 50.7 64.8 66.7 79.9 81 .9 94.1

1 R 17 .4 17 .1 16 .7 16.4 14.0 13 .7 12.2 12.0

3 S 32.8 48.8 65.9 69.4 85.6 88.8 103.8 119.4

1 .5 R 21 .5 21 .0 20.4 17.1 16.7 14.8 14.4 14.1

4 S 39.1 58.4 79.0 82 .5 87 .5 104.8 122.4 141 .0

2 R 24.5 23.9 23 ,1 19.3 16.9 16 .4. 16.0 15.6

5 S 45.7 68.3 75.1 96 .1 101 .3 121 .4 141 .8 144.2

2.5 R 27 .6 26.8 22.1 21 .4 18.6 18.1 17 .6 15.8

6 s

- 52.1 78.0 85.5 109.4 114.9 137 .6 141 .5 162.9

3 R 31 .5 30.4 24.8 24.0 20.7 20.1 18.0 17.4

8 S 63 .7 77.3 104.6 113.4 139.8 146.7 171 .3 197 .4

4 R 37 .3 30.0 28.9 24.7 23.8 21 .1 20 .4 19.7

10 S 75.2 91 .6 104.9 134.3 144.5 173 .1 180.5. 208.1

6 R 49.5 39.3 33.0 31.9 27 .8 26.9 24.1 23 .3

12 S 86.7 105.2 120.2 153 .9 165 .2 197 .9 205.8 237 .3

6 R 48.9 38.7 32.5 31 .2 27 .2 26 .2 23 .5 22 .6

14 S 92.7 113 .1 129.4 165 .7 177 .7 213 .0 220.9 230 .1 8 R 60.0 47 .3 39.4 37.8 32.8 31 .5 27.9 25.1

16 S 104.3 126 .5 144.4 160 .1 175.0 209.7 245.0 254.9

8 R 59,6 46.6 38.8 33 .3 29.2 28.0 26 .8 24.1

18 S 91 .5 116.3 136.7 175.2 191 .5 229.5 241 .7 279.0

10 R 57 .6 47.2 40.2 38.5 33 .7 32.2 28.8 27 .4

Note: Energy Cost = $4.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-2.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $4/MBtu

Pipe Process Fluid TemperatureS (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 1.5 1.5 1.5 1.5 2.0 2.0 2.5 2.5

3 & 1.5 1.5 1.5 1.5 2.0 2.0 2.5 2.5 2.5

4 & 2 1.5 1.5 1.5 2.0 2.5 2.5 2.5 2.5

5 & 2.5 1.5 1.5 2.0 2.0 2.5 2.5 2.5 3.0

6 & 3 1.5 1.5 2.0 2.0 2.5 2.5 3.0 3.0

8 & 4 1.5 2.0 2.0 2.5 2.5 3.0 3.0 3.0

10 & 6 1.5 2.0 2.5 2.5 3.0 3.0 3.5 3.5

12 & 6 •1.5 2.0 2.5 2.5 3.0 3.0 3.5 3.5

14 & 8 1.5 2.0 2.5 2.5 3.0 3.0 3.5 4.0

16 & 8 1.5 2.0 2.5 3.0 3.5 3.5 3.5 4.0

18 & 10 2.0 2.5 3.0 3.0 3.5 3.5 . 4.0 4.0

Note; Energy Cost = $4.00/NBtu

Return Pipe Temperature = 150 F
TABLE B-3 .a

Pipe

Size

(ingh)

Maximum Allowable Heat Losses (Btu/h'ft) from the

Pipe ( S) and the Return Pipe ( R) for Energy Cost of

Process Fluid Temoerature (F)

Supply

$5/MBtu

Pipe

T,xpe 200 250 300 400 450 500

S 25.3 37 .6 50.7 54.1 58.5 70 .1 81 .9 94.1

1 R 17 .4 17 .1 16.7 14.3 12.7 12.5 12 .2 12 .0

3 S 32.8 48.8 54.3 69.4 74.1 79.4 92.8 106.4

1 .5 R 21 .5 21 .0 17.5 17.1 15.1 13 .6 13.4 13 .1

4 S 39.1 58.4 64.5 71 .0 87 .5 93 .1 108.8 125.1

2 R 24.5 23.9 19.8 17 .2 16.9 15.2 14.8 14.5

5 S 45.7 55.6 75.1 82.2 101 .3 107 .3 125.3 144.2

2.5 R 27 .6 22.7 22.1 19.1 18.6 16.6 16.2 15.8

6 S 52.1 63.2 85.5 93 .2 114.9 121 .1 141 .5 162.9

3 R 31 .5 25.6 24.8 21 .4 20.7 18.5 18.0 17.4

8 S 51 .7 77 .3 88.7 113.4 122.4 146 .7 153 .5 176.8

4 R 31 .0 30.0 25.5 24.7 21 .8 21 .1 19.1 18.5

10 S 61 .0 77.5 104.9 117 .2 144.5 154.6 180.5 208 .1 6 R 40.8 34.1 33.0 28.7 27.8 24.9 24.1 23 .3

12 S 70.1 88.9 120.2 134.0 147 .1 176.2 205.8 214.7

6 R 40.4 33 .7 32.5 28.2 25.1 24.3 23 .5 21 .3

14 S 75.1 95.5 129.4 144.1 157 .9 189.2 199.5 210 .5 8 R 49.3 40.9 39.4 34.1 30.0 29.0 26 .0 23 .7

16 S 84.0 106 .6 125.1 141 .9 175.0 189.2 220.9 232 .9

8 R 48.9 40.5 34.6 30.4 29.2 26 .2 25 .2 22.9

18 S 77 .2 100 .9 136.7 155.3 191 .5 206.9 220.8 254.8

10 R 49.2 41 .8 40.2 35.1 33 .7 30.0 27 .2 26.1

Note: Energy Cost = $5.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-3.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $5/MBtu

Pipe Process Flui<i Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 1.5 1.5 1.5 2.0 2.5 2.5 2.5 2.5

3 & 1.5 1.5 1.5 2.0 2.0 2.5 3.0 3.0 3.0

4 & 2 1.5 1.5 2.0 2.5 2.5 3.0 3.0 3.0

5 & 2.5 1.5 2.0 2.0 2.5 2.5 3.0 3.0 3.0

6 & 3 1.5 2.0 2.0 2.5 2.5 3.0 3.0 3.0

8 6c 4 2.0 2.0 2.5 2.5 3.0 3.0 3.5 3.5

10 6c 6 2.0 2.5 2.5 3.0 3.0 3.5 3.5 3.5

12 6c 6

' 2.0 2.5 2.5 3.0 3.5 3.5 3.5 4.0

14 6c 8 2.0 2.5 2.5 3.0 3.5 3.5 4.0 4.5

16 6c 8 2.0 2.5 3.0 3.5 3.5 4.0 4.0 4.5

18 6c 10 2.5 3.0 . 3.0 3.5 3.5 4.0 4.5 4.5

Note: Energy Cost = $5.00/IiBtu

Return Pipe Temperature = 150 F
TABLE B-4.a

Maximum Allowable Heat Losses (Btu/h’ft) from the Supply

Pipe ( S) and the Return Pipe ( R) for Energy Cost of $6/MBtu

Pipe

Size

Process Fluid Temnerature (F)

Pipe

( inch) UQ. 200 250 300 350 400 450 500

2 S 25.3 37 .6 42.4 54.1 58.5 70 .1 81 .9 85.0

1 R 17.4 17.1 14.5 14.3 12.7 12.5 12 .2 11.2

3 S 32.8 40.3 54.3 60.1 74.1 79.4 92.8 106 .4

1 .5 R 21 .5 17.9 17 .5 15.4 15.1 13 .6 13 .4 13 .1

4 S 39.1 47 .8 55.5 71 .0 87 .5 93 .1 108.8 125.1

2 R 24.5 20 .3 17 .6 17 .2 16.9 15.2 14.8 14.5

5 S 37 .3 55.6 64.3 82.2 89.5 107 .3 125.3 144.2

2.5 R 23 .2 22.7 19.6 19.1 17 .0 16 .6 16 .2 15.8

6 S 42.4 63.2 72.9 93 .2 101 .1 121 .1 141 .5 1 46 .6

3 R 26.3 25.6 21 .9 21 .4 19.0 18.5 18.0 16.4

8 S 51 .7 65.6 88.7 99.3 109.7 131 .4 153 .5 160.9

4 R 31 .0 26 .2 25.5 22.4 20.1 19.6 19.1 17 .5

10 S 61 .0 77 .5 91 .6 117 .2 129.0 154.6 163.9 188.8

6 R 40.8 34.1 29.6 28.7 25.6 24.9 22.6 22.0

12 S 70.1 88.9 104,7 119.3 147 .1 159.5 186 .4 196 .6 6 R 40.4 33 .7 29.2 25.9 25.1 22.8 22.1 20.1

14 S 75.1 95.5 112.6 128.0 157 .9 170.8 182.7 194.7

8 R 49.3 40.9 35.3 31 .0 -30.0 26.9 24.5 22.5

16 S 84.0 106 .6 110.9 141 .9 157 .9 172.9 202.0 215.1

8 R 48.9 40.5 31 .4 30.4 27 .1 24.6 23.8 21.8

18 S 77 .2 100.9 121 .2 155.3 172 .7 189.0 220.8 235 .0

10 R 49.2 41 .8 40.2 35.1 33 .7 30.0 27 .2 26.1

Note: Energy Cost = $6 .00/MBtu

Return Pipe Temperature = 150 F
TABLE B-4.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $6/MBtu

Pipe Process Fluid Temnerature: (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 1.5 1.5 2.0 2.0 2.5 2.5 2.5 3.0

3 & 1.5 1.5 2.0 2.0 2.5 2.5 3.0 3.0 3.0

4 6c 2 1.5 2.0 2.5 2.5 2.5 3.0 3.0 3.0

5 6c 2.5 2.0 2.0 2.5 2.5 3.0 3.0 3.0 3.0

6 & 3 2.0 2.0 2.5 2.5 3.0 3.0 3.0 3.5

8 6c 4 2.0 2.5 2.5 3.0 3.5 3.5 3.5 4.0

10 6c 6 2.0 2.5 3.0 3.0 3.5 3.5 4.0 4.0

12 6c 6

' 2.0 2.5 3.0 3.5 3.5 4.0 4.0 4.5

14 6c 8 2.0 2.5 3.0 3.5 3.5 4.0 4.5 5.0

16 6c 8 2.0 2.5 3.5 3.5 4.0 4.5 4.5 5.0

18 6c 10 2.5 3.0 3.5 3.5 4.0 4.5 4.5 5.0

Note: Energy Cost = $6.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-5.a

Maximum Allowable Heat Losses (Btu/h’ft) from the Supply

P ipe ( S) and the Return Pipe ( R) for Energy Cost of $7/MBtu

Pipe

Size

Process Fluid Temnerature (F)

Pipe

Cinch) IXES. UQ. 200 250 300 350 400 450 500

2 S 25.3 31 .5 42.4 47 .4 58.5 70.1 74.0 85.0

1 R 17.4 14.8 14.5 12.9 12 .7 12.5 11 .4 11 .2

3 S 32.8 40.3 47 .1 60.1 66.3 79.4 92.8 106 .6

1 .5 R 21 .5 17.9 15.7 15.4 13.9 13 .6 13.4 13 .1

4 S 39.1 47 .8 55.5 71 .0 77 .7 93 .1 108.8 113 .5 2 R 24.5 20.3 17 .6 17.2 15.5 15.2 14.8 13 .6

5 S 37.3 47 .6 64.3 72.6 89.5 107 .3 125.3 130.2

2.5 R 23 .2 20.0 19.6 17 .4 17 .0 16.6 16 .2 14.9

6 S . 42.4 54.0 72.9 82.0 101 .1 121 .1 127 .4 146 .6 3 R 26.3 22.5 21 .9 19.4 19.0 18.5 16.8 16.4

8 S 44.0 65.6 88.7 99.3 109.7 131.4 139.9 160.9

4 R 26.9 26.2 25.5 22.4 20.1 19.6 18.0 17.5

10 S 51 .8 67 .7 91 .6 104.6 129.0 140.3 163 .9 173 .6

6 R 35.1 30.4 29.6 26.3 25.6 23 .2 22.6 20.8

12 S 59.4 77 .5 104.7 119.3 133.2 146 .1 170 .7 182 .0

6 R 34.8 30.1 29.2 25.9 23 .4 21 .4 20.8 19.1

14 S 63.7 83 .2 100.0 128.0 142.6 156 .4 169.0 181 .6 8 R 42.4 36.4 32 .0 31 .0 27 .8 25.2 23 .1 21 .4

16 S 71 ,1 92 .4 110.9 128.0 144.3 172.9 186.6 200 .3 8 R 42 .0 35.9 31 .4 28.1 25.4 24.6 22.6 20.9

18 S 67 .2 89.5 121 .2 140 .0 157 .7 189.0 203.8 218.7

10 R 43.3 37 .8 36.5 32.4 29.2 28.2 25.8 23.8

Note: Energy Cost = $7 .00/MBtu

Return Pipe Temperature = 150 F
TABLE B-5.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $7/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 1.5 2.0 2.0 2.5 2.5 2.5 3.0 3.0

3 6c 1.5 1.5 2.0 2.5 2.5 3.0 3.0 3.0 3.0

4 6c 2 1.5 2.0 2.5 2.5 3.0 3.0 3.0 3.5

5 6c 2.5 2.0 2.5 2.5 3.0 3.0 3.0 3.0 3.5

6 6c 3 2.0 2.5 2.5 3.0 3.0 3.0 3.5 3.5

8 6c 4 2.5 2.5 2.5 3.0 3.5 3.5 4.0 4.0

10 & 6 2.5 3.0 3.0 3.5 3.5 4.0 4.0 4.5

12 6c 6 '2.5 3.0 3.0 3.5 4.0 4.5 4.5 5.0

14 5c 8 2.5 3.0 3.5 3.5 4.0 4.5 5.0 5.5

16 6c 8 2.5 3.0 3.5 4.0 4.5 4.5 5.0 5.5

18 6c 10 3.0 3.5 3.5 4.0 4.5 4.5 5.0 5.5

Note: Energy Cost = $7.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-6.a

Maximum Allowable Heat Losses (Btu/h*ft) from the Supply

Pipe ( S) and the Return Pipe (R) for Energy Cost of $8/MEtu

Pipe

Size

Process Fluid Temnerature (F)

Pipe

(inch) IXES. UQ. 200 250 300 3^0 400 450 500

2 S 25.3 31 .5 37 .2 47 .4 58.5 6T3 .3 74.0 85.0

1 R 17 .4 14.8 13.1 12.9 12.7 11 .6 11.4 11 .2

3 S 27 .1 40.3 47 .1 • 60.1 66.3 79.4 92.8 106 .6

1 .5 R 18.2 17.9 15.7 15.4 13.9 13 .6 13.4 13 .1

4 S 32.1 41 .2 55.5 71 .0 77 .7 93 .1 98.7 113 .5 2 R 20.7 18.0 17 .6 17 .2 15.5 15.2 13.9 13 .6

5 S 37.3 47 .6 64.3 72.6 89.5 107 .3 113 .2 130.2

2.5 R 23 .2 20.0 19.6 17 .4 17 .0 16.6 15.2 14.9

6 S 42.4 54.0 64.2 82.0 101 .1 109.0 127 .4 134.1

3 R 26 .3 22.5 19,9 19.4 19.0 17 .2 16.8 15.5

8 S 44.0 65.6 77 .7 89.0 109.7 119.7 139.9 148.4

4 R 26.9 26.2 23 .0 20.6 20.1 18.4 18.0 16.7

10 S 51.8 67 .7 81 .8 104.6 117 .1 140.3 150.8 173 .6

6 R 35.1 30.4 27 .0 26 .3 23.8 23 .2 21 .4 20,8

12 S 59.4 77 .5 93.3 108.0 122.0 146 .1 158.1 182 .0

6 R 34.8 30.1 26.7 24.1 21 .9 21 .4 19.7 19.1

14 S 63 .7 83 .2 100.0 115.6 130.5 156 .4 169.0 181 .6 8 . R 42.4 36.4 32.0 28.6 25.9 25.2 23 .1 21 .4

16 S 61 .7 82,0 110.1 117 .1 144.3 172.9 186.6 200.3

8 R 37 .0 32.4 28.9 26.2 25.4 24.6 22 .6 20.9

18 S 67 .2 89.5 109.4 127 .9 157 .7 174.5 189.7 218.7

10 R 43 .3 37 .8 33.5 30.2 29.2 26.7 24.6 23.8

Note: Energy Cost = $8.00/MEtu

Return Pipe Temperature = 150 F
TABLE B-6.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $8/MBtu

Pipe Process Fluid Temnerature^ (F)

Size

( inch) 150 200 250 300 350 400 450. 500

2 & 1 1.5 2.0 2.5 2.5 2.5 3.0 3.0 3.0

3 & 1.5 2.0 2.0 2.5 2.5 3.0

/ 3.0 3.0 3.0

4 & 2 2.0 2.5 2.5 2.5 3.0 3.0 3.5 3.5

5 & 2.5 2.0 2.5 2.5 3.0 3.0 3.0 3.5 3.5

6 & 3 2.0 2.5 3.0 3.0 3.0 3.5 3.5 4.0

8 & 4 2.5 2.5 3.0 3.5 3.5 4.0 4.0 4.5

10 & 6 2.5 3.0 3.5 3.5 4.0 4.0 4.5 4.5

12 & 6 2.5 3.0 3.5 4.0 4.5 4.5 5.0 5.0

14 & 8 2.5 3.0 • 3.5 4.0 4.5 4.5 5.0 5.5

16 & 8 3.0 3.5 4.0 4.5 4.5 4.5 5.0 5.5

18 & 10 3.0 3.5 4.0 4.5 4.5 5.0 5.5 5.5

Note: Energy Cost = $8.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-7.a

Maximum Allowable Heat Losses (Btu/h’ft) from the Supply

Pipe (S) and the Return Pipe (R) for Energy Cost of $9/MBtu

Pipe Process Fluid Temperature CF') Size Pipe

( inch) Tvne 150 200 250 300 350 400 450 500

2 S 21,.2 27,.6 37,.2 47,.4 58..5 63,,3 74,.0 85,,0

1 R 15,.0 13..3 13,.1 12,.9 12,.7 11,,6 11,,4 11,.2

3 S 27,,1 34,.9 47 . 1 53,.8 66

.

.3 79,,4 92..8 97,,3

1.5 R 18,,2 15,.9 15 .7 14,.1 13,,9 13,.6 13,.4 12,.3

4 S 32,,1 41,.2 5'5 .5 63 .0 77,.7 84,. 5 98,.7 113,.5

2 R 20,.7 18,.0 17 .6 15 .8 15 .5 14,.2 13 .9 13 .6

5 S 37,.3 47 .6 56 .9 72 .6 89,.5 96 .9 113 .2 119 .5 2.5 R 23,.2 20 .0 17 .8 17 .4 17,.0 15,.5 15 .2 14 . 1

6 S 36,,2 54,.0 64 .2 82 .0 91,.0 109,.0 116,.6 124 .2

3 R 23,.0 22 .5 19 .9 19 .4 17,.6 17,.2 15,.8 14 .7

8 S 38,.6 57,.5 77 .7 89 .0 109,.7 119,.7 129,.1 138,.3 4 R 24,,1 23,.5 23 .0 20,.6 20,.1 18,.4 17,,0 • 15,,9

10 S 45..4 60,,6 81,.8 104,.6 117,.1 129,,1 150,.8 161,.0

6 R 31,,2 27,,6 27,.0 26,.3 23,,8 21,,9 21,.4 19,.7

12 S 51.,9 69,,1 93..3 108,.0 122,.0 135..3 158,.1 169.,9 6 R 30.,9 27,.4 26,,7 24,.1 21.,9 20.,2 19,, 7 18,.3

14 S 55.,6 74.,0 90.,4 105.,8 130. 5 144. 7 157. 7 181.,6 8 R 37. 4 32.,9 29.,4 26. 6 25. 9 23. 8 22. 0 21. 4

16 S 61. 7 82. 0 100. 1 117. 1 144. 3 159. 8 173. 9 200. 3 8 R 37. 0 32. 4 28. 9 -26. 2 25. 4 23. 3 21. 5 20. 9

18 S 59. 8 89. 5 109. 4 127. 9 157. 7 174. 5 189. 7 205. 0

10 R 39. 0 37. 8 33. 5 30. 2 29. 2 26. 7 24. 6 22. 8

Note: Energy Cost = $9.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-7.b

Economic Insulation Thickness (inch) for Steam Supply

and Re turn Pipes for Energy Cost of $9/MBtu

Pipe Process Fluid Temnerature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 2.0 2.5 2.5 2.5 2.5 3.0 3.0 3.0

3 & 1.5 2.0 2.5 2.5 3.0 3.0 3.0 3.0 3.5

4 & 2 2.0 2.5 2.5 3.0 3.0 3.5 3. .5 3.5

5 & 2.5 2.0 2.5 3.0 3.0 3.0 3.5 3.5 4.0

6 & 3 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.5

8 & 4 3.0 3.0 3.0 3.5 3.5 4.0 4.5 5.0

10 & 6 3.0 3.5 3.5 3.5 4.0 4.5 4.5 5.0

12 & 6 3.0 3.5 3.5 4.0 4.5 5.0 5.0 5.5

14 & 8 3.0 3.5 4.0 4.5 4.5 5.0 5.5 5.5

16 & 8 3.0 3.5 4.0 4.5 4.5 5.0 5.5 5.5

18 & 10 3.5 3.5 4.0 4.5 4.5 5.0 5.5 6.0

Note: Energy Cost = $9.00/NBtu

Return Pipe Temperature = 150 F
TABLE B-8.a

Maximum Allowable Heat Losses (Btu/h*ft) from the Supply

Pipe (S) and the Return Pipe ( R) for Energy Cost of $10/MBtu

Pipe

Size

(inch)

Process Fluid Temnerature (F)

Pipe

Uil 200 250 300 150 400 450 500

2 S ' 21 .2 27 .6 37 .2 47.4 52.8 63.3 74.0 78.2

1 R 15.0 13.3 13 .1 12.9 11 .7 11 .6 11 .4 10.6

3 S 27.1 34.9 47 .1 53 .8 66,3 79.4 84.7 97 .3

1 .5 R 18.2 15.9 15.7 14.1 13.9 13 .6 12 .6 12 .3

4 S 27 .7 41 .2 55.5 63 .0 77 .7 84.5 98.7 113 .5

2 R 18.3 18.0 17 .6 15.8 15.5 14.2 13.9 13 .6

5 S 32.0 47 .6 56.9 72.6 89.5 96.9 113.2 119.5

2.5 R 20.4 20.0 17.8 17.4 17 .0 15.5 15.2 14.1

6 S 36.2 54.0 64.2 82.0 91 .0 109.0 116 .6 124.2

3 R 23 .0 22.5 19.9 19.4 17.6 17.2 15.8 14.7

8 S 38.6 57.5 69.6 89.0 99.9 110.5 129.1 138.3

4 R 24.1 23 .5 21 .1 20.6 18.8 17.4 17 .0 15.9

10 S 45.4 60 .6 81 .8 95.0 107 .8 129.1 140 .0 150 .6

6 R 31 .2 27 .6 27 .0 24.4 22.4 21.9 20.2 18.8

12 S 51.9 69.1 84.5 98.9 112.9 135,3 147 .6 159.7

6 R 30.9 27.4 24.7 22.5 20.7 20.2 18.8 17.5

14 S 55.6 74.0 90.4 105.8 120.7 135.0 157 .7 170 .5 8 R 37 .4 32.9 29.4 26 .6 24.4 22.6 22.0 20.5

16 S 54.9 74.0 91 .5 117 .1 133.4 148.9 173.9 187 .9

8 R 33 .4 29.8 26.9 26 .2 24.0 22.1 21 .5 20.0

18 S 59.8 80.8 99.9 127 .9 145.6 162 .4 177.9 205.0

10 R 39.0 34.6 31 .2 30.2 27 .2 25.4 23 .5 22.8

Note: Energy Cost = $10.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-8.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $10/MBtu

Pipe Process Fluid Temnerature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 2.0 2.5 2.5 2.5 3.0 3.0 3.0 3.5

3 & A-5 2.0 2.5 2.5 3.0 3.0 3.0 3.5 3.5

4 & 2 2.5 2.5 2.5 3.0 3.0 3.5 3.5 3.5

5 6c 2.5 2.5 2.5 3.0 3.0 3.0 3.5 3.5 4.0

6 6c 3 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.5

8 6c 4 3.0 3.0 3.5 3.5 4.0 4.5 4.5 5.0

10 6c 6 3.0 3.5 3.5 4.0 4.5 4.5 5.0 5.5

12 6c 6 '3.0 3.5 4.0 4.5 5.0 5.0 5.5 6.0

14 6c 8 3.0 3.5 4.0 4.5 5.0 5.5 5.5 6.0

16 6c 8 3.5 4.0 4.5 4.5 5.0 5.5 5.5 6.0

18 6c 10 3.5 4.0 4.5 4.5 5.0 5.5 6.0 6.0

Note: Energy Cost = $10.00/NBtu

Return Pipe Temperature = 150 F
TABLE B-9.a

Maximum Allowable Heat Losses (Btu/h’ft) from the Supply

Pipe (S) and the Return Pipe ( R) for Energy Cost of $ll/MBtu

Pipe

Size

(inch)

Process Fluid Temnerature (F)

Pipe

UQ. 200 250 300 350 400 450 500

2 S 18.6 27 .6 37 .2 42.8 52.8 63 .3 68,1 78.2

1 R 13.4 13.3 13 .1 11 .9 11 .7 11 .6 10 .7 10.6

3 S 23.5 34.9 42.1 53 .8 66.3 72.5 84.7 97 .3

1 .5 R 18.2 15.9 14.4 14.1 13.9 12.8 12 .6 12.3

4 S 27 .7 41 .2 49.4 63.0 70 .6 84.5 98.7 113.5

2 R 18.3 18.0 16.1 15.8 14.4 14.2 13.9 13 .6

5 S 32.0 42.2 56.9 72.6 80.9 96.9 104.0 119.5

2.5 R 20.4 18.1 17 .8 17.4 15.8 15.5 14.4 14.1

6 S 36.2 47 .6 64.2 73.8 91 .0 99.8 108.1 116.2

3 R 23 .0 20.3 19.9 17.9 17 .6 16.2 15.0 14.1

8 S 38.6 57.5 69.6 89.0 99.9 110.5 120.3 129.9

4 R 24.1 23.5 21 .1 20.6 18.8 17.4 16.2 15.3

10 S 45.4 60.6 74.3 95.0 107 .8 119.8 140 .0 150 .6 6 R 31 .2 27 .6 25.0 24.4 22.4 20.6 20.2 18.8

12 S 46 .4 69.1 84.5 98.9 112,9 126 .3 147 .6 159.7

6 R 28.0 27 .4 24.7 22.5 20.7 19.2 18.8 17.5

14 S 49.5 74.0 90.4 105.8 120.7 135.0 157 .7 170 .5 8 R 33 .7 32.9 29.4 26 .6 24.4 22.6 22 .0 20.5

16 S 54.9 74.0 91 .5 117 .1 133.4 148.9 163.2 187 .9

8 R 33.4 29.8 26.9 26 .2 24.0 22.1 20 .6 20.0

18 S 59.8 80.8 99.9 118.1 135.6 162 .4 177.9 205.0

10 R 39.0 34.6 31 .2 28.4 26.1 25.4 23 .5 22.8

Note: Energy Cost = $11.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-9.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $ll/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 2.5 2.5 2.5 3.0 3.0 3.0 3.5 3.5

3 & 1.5 2.5 2.5 3.0 3.0 3.0 3.5 3.5 3.5

4 & 2 2.5 2.5 3.0 3.0 3.5 3.5 3.5 3.5

5 & 2.5 2.5 3.0 3.0 3.0 3.5 3.5 4.0 4.0

6 & 3 2.5 3.0 3.0 3-5 3.5 4.0 4.5 5.0

8 6c 4 3.0 3.0 3.5 3.5 4.0 4.5 5.0 5.5

10 6c 6 3.0 3.5 4.0 4.0 4.5 5.0 5.0 5.5

12 6c 6 '3.5 3.5 4.0 4.5 5.0 5.5 5.5 6.0

14 6c 8 3.5 3.5 4.0 4.5 5.0 5.5 5.5 6.0

16 6c 8 3.5 4.0 4.5 4.5 5.0 5.5 6.0 6.0

18 6c 10 3.5 4.0 4.5 5.0 5.5 5.5 6.0 6.0

Note: Energy Cost = $11.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-lO.a

Maximum Allowable Heat Losses (Btu/h'ft) from the Supply

Pipe (S) and the Return Pipe ( R) for Energy Cost of $12/MBtu

Pipe

Size

Cinch)

Process Fluid Temnerature (F)

Pipe

Tjp-q lid 200 250 300 350 400 450 500

2 S 18.6 27 .6 37 .2 42.8 52.8 63 .3 68.1 78.2

1 R 13.4 13 .3 13.1 11 .9 11 .7 11 .6 10.7 10.6

3 S 23.5 34.9 42.1 53 .8 66.3 72.5 .84.7 90 .1

1 .5 R 16.2 15.9 14.4 14.1 13.9 12.8 12 .6 11.7

4 S 27 .7 41 .2 49.4 63 .0 70 .6 84.5 98.7 104.6

2 R 18.3 18.0 16 .1 15.8 14.4 14.2 13.9 12.9

5 S 32.0 42.2 56.9 72.6 80.9 96.9 104.0 119.5

2.5 R 20.4 18.1 17.8 17.4 15.8 15.5 14.4 14.1

6 S

' 36.2 47 .6 64.2 73.8 91 .0 99.8 108.1 116.2

3 R 23.0 20.3 19.9 17.9 17 .6 16.2 15.0 14.1

8 S 34.7 51 .6 69.6 81 .1 92.2 102.9 120.3 129.9

4 R 22.0 21 .5 21 .1 19.2 17 .8 16.6 16.2 15.3

10 S 40 .6 60 .6 74.3 87 .4 107 .8 119.8 131 .0 150 .6

6 R 28.2 27 .6 25.0 22.8 22.4 20.6 19.2 18.8

12 S 46.4 62.6 77.4 91 .6 112.9 126 .3 138.8 159.7

6 R 28.0 25.3 23 .0 21 .2 20.7 19.2 18.0 17.5

14 S 49.5 66.9 82 .8 97 .9 112.7 135.0 148.2 170 .5

8 R 33.7 30.1 27 .3 25.0 23 .1 22.6 21 .0 20.5

16 S 54.9 74.0 91 .5 108.1 124.3 148.9 163.2 187 .9

8 R 33.4 29.8 26.9 24.6 22.7 22.1 20.6 20.0

18 S 59.8 80.8 99.9 118.1 135.6 152.3 177.9 205.0

10 R 39.0 34.6 31 .2 28.4 26.1 24.2 23.5 22.8

Note: Energy Cost = $12.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-lO.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $12/MBtu

Pipe ____ Size

(inch) 150

Process Fluid

200

2 & 1 2.5 2.5

3 & 1.5 2.5 2.5

4 & 2

CM in 2.5

5 & 2.5 2.5 3.0

6 & 3 2.5 3.0

8 & 4 3.5 3.5

10 & 6 3.5 3.5

12 & 6 '3.5 4.0

14 & 8 3.5 4.0

16 & 8 3.5 4.0

18 & 10 3.5 4.0

250 300 350

2.5 3.0 3.0

3.0 3.0 3.0

3.0 3.0 3.5

3.0 3.0 3.5

3.0 3.5 3.5

3.5 4.0 4.5

4.0 4.5 4.5

4.5 5.0 5.0

4.5 5.0 5.5

4.5 5.0 5.5

4.5 5.0 5.5

400 450 500

3.0 3.5 3.5

3.5 3.5 4.0

3.5 3.5 4.0

3.5 4.0 4.0

4.0 4.5 5.0

5.0 5.0 5.5

5.0 5.5 5.5

5.5 6.0 6.0

5.5 6.0 6.0

5.5 6.0 6.0

6.0 6.0 6.0

Note: Energy Cost = $12.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-11 .a

Maximum Allowable Heat Losses (Btu/h’ft) from the Supply

Pipe (S) and the Return Pipe ( R) for Energy Cost of $13/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

(inch) TxP-Q UQ. 200 250

2 S 18.6 27 .6 33.6

1 R 13.4 13 .3 12 .1

3 S 23.5 31 .3 42,1

1 ,5 R 16.2 14,6 14.4

4 S 27 .7 36.6 49.4

2 R 18.3 16.3 16.1

5 S 32.0 42.2 56.9

2.5 R 20.4 18.1 17.8

6 S 32.0 47 .6 57.8

3 R 20.7 20.3 18.3

8 S 3U.7 51 .6 69.6

4 R 22.0 21 .5 21 .1

10 S 40.6 60.6 74.3

6 R 28.2 27 .6 25.0

12 S 46.4 62.6 77 .4

6 R 28.0 25.3 23 .0

14 S 49.5 66.9 82.8

8 R 33.7 30.1 27 .3

16 S 49.6 67 .7 91 .5

8 R 30.5 27 .6 26.9

18 S 54.0 73.9 92.3

10 R 35.5 32.0 29.2

300 350 400 450 500

42.8

11 .9

52.8

11 ,7

58.3

10.9

68.1

10.7

78.2

10.6

53 .8

14.1

60.5

13.0

72.5

12.8

84.7

12.6

90.1

11.7

57 .2

14.7

70 .6 14.4

84.5

14.2

98.7

13.9

104.6

12.9

65.6

16.1

80.9

15.8

96.9

15.5

104.0

14.4

119.5

14.1

73.8

17.9

83.3

16.5

99.8

16.2

108.1

15.0

116.2

14.1

81 .1 19.2

92,2

17 .8

102.9

16 .6 113.015.6

129.9

15.3

87 .4

22.8

100.0

21 .1 112.1

19.6

131 .0 19.2141 .9

18.0

91 .6

21 .2

105.5

19.6

118.8

18.4

138.8

18.0

159.7

17 .5

97 .9

25.0

112.7

23 .1 126.821 .5 148.2

21 .0

170 .5 20.5

108.1

24.6

124.3

22.7

139.7

21 .2 163.2

20 .6 187 .9

20.0

109.9

26.8

127 .1 24.9152.3

24.2

177.9

23 .5 205.022.8

Note: Energy Cost = $13 .00/MEtu

Return Pipe Temperature = 150 F
TABLE B-ll.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $13/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 2.5 2.5 3.0 3.0 3.0 3.5 3.5 3.5

3 & 1.5 2.5 3.0 3.0 3.0 3.5 3.5 3.5 4.0

4 & 2 2.5 3.0 3.0 3.5 3.5 3.5 3.5 4.0

5 & 2.5 2.5 3.0 3.0 3.5 3.5 3.5 4.0 4.0

6 & 3 3.0 3.0 3.5 3.5 4.0 4.0 4.5 5.0

8 & 4 3.5 3.5 3.5 4.0 4.5 5.0 5.5 5.5

10 & 6 3.5 3.5 4.0 4.5 5.0 5.5 5.5 6.0

12 & 6 -3.5 4.0 4.5 5.0 5.5 6.0 6.0 6.0

14 & 8 3.5 4.0 4.5 5.0 5.5 6.0 6.0 6.0

16 & 8 4.0 4.5 4.5 5.0 5.5 6.0 6.0 6.0

18 & 10 4.0 4.5 5.0 5.5 6.0 6.0 6.0 6.0

Note: Energy Cost = $13.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-12.a

Maximum Allowable Heat Losses (Btu/h'ft) from the Supply

Pipe (S) and the Return Pipe ( R) for Energy Cost of $14/MBtu

Pipe

Size

(Jjgh)

Process Fluid Temnerature (F)

Pipe

Type UQ. 200 250 350 400 450 500

2 S 18.6 27 .6 33.6 42.8 52.8 58.3 68.1 78.2

1 R 13 .4 13.3 12.1 11.9 11 .7 10.9 10.7 10.6

3 S 21 .1 31 .3 42.1 53.8 60.5 72.5 78.5 90 .1

1 .5 R 14.8 14.6 14.4 14.1 13 .0 12.8 11 .9 11.7

4 S 27 .7 36.6 49.4 . 57 .2 70 .6 84.5 91 .0 104.6

2 R 18.3 16.3 16 .1 14.7 14.4 14.2 13 .1 12.9

5 S 32.0 42.2 56.9 65.6 80.9 89.0 104.0 119.5

2.5 R 20.4 18.1 17.8 16.1 15.8 14.6 14.4 14.1

6 s

- 32.0 47 .6 57 .8 73.8 83.3 92.5 101 .1 109.5

3 R 20.7 20.3 18.3 17.9 16.5 15.3 14.4 13 .6

8 S 34.7 51 .6 69.6 81 .1 92.2 102.9 113.0 122 .7 4 R 22.0 21 .5 21 .1 19.2 17 .8 16.6 15.6 14.7

10 S 40.6 55.1 68.4 87 .4 100.0 112.1 123 .4 141 .9

6 R 28.2 25.5 23.3 22.8 21 .1 19.6 18.3 18.0

12 S 46.4 62.6 77 .4 91 .6 105.5 118.8 138.8 159.7

6 R 28.0 25.3 23 .0 21 .2 19.6 18.4 18.0 17.5

14 S 49.5 66.9 82.8 91 .3 112.7 126.8 148.2 170 .5 8 R 33 .7 30.1 27.3 23 .6 23 .1 21 .5 21 .0 20.5

16 S 49.6 67 .7 91 .5 100.8 116.6 139.7 163.2 187 .9

8 R 30.5 27 .6 26.9 23.3 21 .7 21 .2 20.6 20.0

18 S 54.0 73.9 92.3 109.9 127 .1 152.3 177.9 205.0

10 R 35.5 32.0 29.2 26.8 24.9 24.2 23 .5 22.8

Note: Energy Cost = $14.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-12.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $14/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 150 200 250 300 350 400 450 500

2 & 1 2.5 2.5 3.0 3.0 3.0 3.5 3.5 3.5

3 & 1.5 3.0 3.0 3.0 3.0 3.5 3.5 4.0 4.0

4 & 2 2.5 3.0 3.0 3.5 3.5 3.5 4.0 4.0

5 & 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.0 4.0

6 & 3 3.0 3.0 3.5 3.5 4.0 4.5 5.0 5 .

5

8 & 4 3.5 3.5 3.5 4.0 4.5 5.0 5.5 6.0

10 & 6 3.5 4.0 4.5 4.5 5.0 5.5 6.0 6.0

12 & 6 '3.5 4.0 4.5 5.0 5.5 6.0 6.0 6.0

14 & 8 3.5 4.0 4.5 5.5 5.5 6.0 6.0 6.0

16 & 8 4.0 4.5 4.5 5.5 6.0 6.0 6.0 6.0

18 & 10 4.0 4.5 5.0 5.5 6.0 6.0 6.0 6.0

Note: Energy Cost = $14.00/MBtu

Return Pipe Temperature = 150 F
TABLE B-13.a

Maximum Allowable Heat Losses (Btu/h*ft) from the Supply

Pipe ( S) and the Return Pipe ( R) for Energy Cost of $15/KBtu

Pipe

Size

(inch)

Process Fluid Temnerature (F)

Pipe

Ty££ UQ. 200 250 300 350 400 450 lOQ

2 S 18.6 27 .6 33 .6 42.8 52.8 58.3 68.1 78.2

1 R 13.4 13.3 12.1 11.9 11 .7 10.9 10.7 10.6

3 S 21 .1 31 .3 42.1 53 .8 60.5 72.5 78.5 90.1

1 .5 R 14.8 14.6 14.4 14.1 13 .0 12.8 11.9 11.7

4 S 27 .7 36.6 49.4 57 .2 70 .6 84.5 91 .0 104.6

2 R 18.3 16.3 16.1 14.7 14.4 14.2 13 .1 12.9

5 S 32.0 42.2 56.9 65.6 80.9 89.0 104.0 119.5

2.5 R 20.4 18.1 17 .8 16.1 15.8 14.6 14.4 14.1

6 S 32.0 47 .6 57 .8 67.6 77.2 86.5 95.3 103.9

3 R 20.7 20.3 18.3 16 .8 15.6 14.6 13.8 13.1

8 S 34.7 51 .6 69.6 81 .1 92.2 102.9 113.0 122.7

4 R 22.0 21 .5 21 .1 19.2 17 .8 16.6 15.6 14.7

• 10 S 40.6 55.1 68.4 87 .4 100.0 112.1 123 .4 141 .9

6 R 28.2 25.5 23 .3 22.8 21 .1 19.6 18.3 18.0

12 S 46.4 62.6 77 .4 91 .6 105.5 118.8 138.8 159.7

6 R 28.0 25.3 23 .0 21 .2 19.6 18.4 18.0 17.5

14 S 49.5 66.9 82.8 91 .3 112.7 126 .8 148.2 170 .5

8 R 33 .7 30.1 27 .3 23 .6 23 .1 21 .5 21 .0 20.5

16 S 49.6 67,7 91 .5 100.8 116.6 139.7 163 .2 187 .9

8 R 30.5 27 .6 26.9 23 .3 21 .7 21 .2 20.6 20.0

18 S 54.0 73.9 92.3 109.9 127 .1 152.3 177.9 205.0

10 R 35.5 32.0 29.2 26.8 24.9 24.2 23.5 22.8

Note: Energy Cost = $15.00/MBtu

Return Pipe Temperature = 150 F
TABLE B

- 13 .b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $15/MBtu

Pipe

Size

( inch)

Process Fluid Temoerature (F)

150 200 250 300 350 400 450 500

2 6e 1 2.5 2.5 3.0 3.0 3.0 3.5 3.5 3.5

3 & 1.5 3.0 3.0 3.0 3.0 3.5 3.5 4.0 4.0

4 & 2 2.5 3.0 3.0 3.5 3.5 3.5 4.0 4.0

5 & 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.0 4.0

6 6c 3 3.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0

8 6c 4 3.5 3.5 3.5 4.0 4.5 5.0 5.5 6.0

10 6c 6 3.5 4.0 4.5 4.5 5.0 5.5 6.0 6.0

12 6c 6

' 3.5 4.0 4.5 5.0 5.5 6.0 6.0 6.0

14 6c 8 3.5 4.0 4.5 5.5 5.5 6.0 6.0 6.0

16 6c 8 4.0 4.5 4.5 5.5 6.0 6.0 6.0 6.0

18 & 10 4.0 4.5 5.0 5.5 6.0 6.0 6.0 6.0

Note: Energy Cost = $15.00/MBtu

Return Pipe Temperature = 150 F
TABLE C-l.a

Maximum Allowable Heat Losses (Btu/h-ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $3/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Tvne 250 300 350 400 450 500

1 S 34. 8 44,.6 55,,1 66. 1 77. 3 89..1 R 34. 8 34,.5 34,,3 34. 0 33. 7 33.,4

2 S 49. 6 53,,4 65.,9 69. 5 81. 3 93..6 R 49. 6 41,.3 40.,9 35. 8 35. 5 35.,2

3 S 53. 1 68,,2 84. 3 87. 9 92. 1 106,,0

R 53. 1 52,,6 52.,0 45 . 0 40. 2 39,.8

4 S 62. 9 69,,8 86.,3 103. 6 107. 8 124,, 3 R 62. 9 53,,9 53.,3 52. 8 46. 8 46,.3

5 S 73. 0 80,.7 99.,8 119. 8 124. 1 143,.1 R 73. 0 62,,1 61.,4 60. 7 53. 6 53,,0

6 S 82. 8 91,,3 112.,9 135. 6 140. 0 161,,5

R 82. 8 70,,2 69..3 68. 4 60. 1 59,.4

8 S 100. 7 110,.7 137.,1 144. 6 151.,8 175,.3 R 100. 7 84,.8 73,,0 66.,3 65.,3 64 .5

10 S 101. 5 130,.9 141

,9 170. 5 178. 5 206,.2

R 101. 5 100,.0 86,,8 85.,6 76. 2 75,.1

12 S 115. 7 149,,5 161,,8 194. 5 202. 8 234,.4

R 115. 7 113,,8 98..6 97. 1 85. 9 84,.6

14 S 124. 7 161

,2 173.,5 208. 7 217. 4 251,,5

R 124. 7 122,,6 105. 4 103. 6 91. 5 90,,0

16 S 137. 3 154,,8 191. 8 205. 3 240. 5 251. 4

R 137. 3 117.,9 115. 8 102. 1 100. 3 90. 0

18 S 149. 7 169. 2 186. 7 224. 6 263. 2 275. 2‘ R 149. 7 128. 5 113. 0 110. 9 108. 8 97. 6

Note; Energy Cost = $3.00/MBtu

Return Pipe Temperature = 250 F
TABLE B-13.b

Economic Insulation Thickness (inch) for Steam Supply

and Return Pipes for Energy Cost of $15/MBtu

Pipe

Size

( inch)

Process Fluid Temoerature (F)

150 200 250 300 350 400 450 500

2 & 1 2.5 2.5 3.0 3.0 3.0 3.5 3.5 3.5

3 & 1.5 3.0 3.0 3.0 3.0 3.5 3.5 4.0 4.0

4 & 2 2.5 3.0 3.0 3.5 3.5 3.5 4.0 4.0

5 & 2.5 2.5 3.0 3.0 3.5 3.5 4.0 4.0 4.0

6 & 3 3.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0

8 & 4 3.5 3.5 3.5 4.0 4.5 5.0 5.5 6.0

10 & 6 3.5 4.0 4.5 4.5 5.0 5.5 6.0 6.0

12 & 6 3.5 4.0 4.5 5.0 5.5 6.0 6.0 6.0

14 & 8 3.5 4.0 4.5 5.5 5.5 6.0 6.0 6.0

16 & 8 4.0 4.5 4.5 5.5 6.0 6.0 6.0 6.0

18 & 10 4.0 4.5 5.0 5.5 6.0 6.0 6.0 6.0

Note: Energy Cost = $15.00/NBtu

Return Pipe Temperature = 150 F
TABLE C-l.a

Maximum Allowable Heat Losses (Btu/h’ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $3/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Type 250 300 350 400 450 500

1 S 34. 8 44. 6 55.,1 66. 1 77. 3 89. 1 R 34. 8 34.,5 34.,3 34. 0 33. 7 33. 4

2 S 49. 6 53. 4 65. 9 69. 5 81. 3 93. 6 R 49. 6 41. 3 40.,9 35. 8 35. 5 35. 2

3 S 53. 1 68. 2 84. 3 87. 9 92. 1 106. 0

R 53. 1 52. 6 52.,0 45. 0 40. 2 39. 8

4 S 62. 9 69. 8 86.,3 103. 6 107. 8 124. 3 R 62. 9 53. 9 53.,3 52. 8 46. 8 46. 3

5 S 73. 0 80.,7 99, 8 119. 8 124. 1 143.,1

R 73. 0 62.,1 61,,4 60. 7 53. 6 53.,0

6 S 82. 8 91.,3 112,,9 135. 6 140. 0 161.,5

R 82. 8 70.,2 69,,3 68. 4 60. 1 59.,4

8 S 100. 7 110.,7 137,, 1 144. 6 151. 8 175,,3

R 100..7 84,,8 73,,0 66

3 65. 3 64,,5

10 S 101.,5 130.,9 141,,9 170. 5 178. 5 206,,2

R 101.,5 100,.0 86,,8 85. 6 76. 2 75,, 1

12 S 115.,7 149.,5 161,,8 194. 5 202. 8 234,,4

R 115.J 113,,8 98,,6 97. 1 85. 9 84,,6

14 S 124. 7 161.,2 173,,5 208. 7 217. 4 251. 5 R 124. 7 122. 6 105.,4 103. 6 91. 5 90. 0

16 S 137. 3 154. 8 191. 8 205. 3 240. 5 251. 4

R 137. 3 117. 9 115. 8 102. 1 100. 3 90. 0

18 S 149. 7 169. 2 186. 7 224. 6 263. 2 275. 2' R 149. 7 128. 5 113. 0 110. 9 108. 8 97. 6

Note: Energy Cost = $3.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-l.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $3/MBtu

Pipe Process Fluid Temperature (F)

Size

(inch) 250 300 350 400 450 500

1 1.5 1.5 1.5 1.5 1.5 1.5

2 1.5 2.0 2.0 2.5 2.5 2.5

3 2.0 2.0 2.0 2.5 3.0 3.0

4 2.0 2.5 2.5 2.5 3.0 3.0

5 2.0 2.5 2.5 2.5 3.0 3.0

6 2.0 2.5 2.5 2.5 3.0 3.0

8 2.0 2.5 2.5 3.0 3.5 3.5

10 2.5 2.5 3.0 3.0 3.5 3.5

12 2.5 2.5 3.0 3.0 3.5 3.5

14 2.5 2.5 3.0 3.0 3.5 3.5

16 2.5 3.0 3.0 ,3.5 3.5 4.0

18 2.5 3.0 3.0 3.5 3.5 4.0

Note: Energy Cost = $3.00/NBtu

Return Pipe Temperature = 250 F
TABLE C-2.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $4/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Type 250 300 350 400 450 500

1 S 34.8 44.6 55.1 56,, 7 66.3 76.3

R 34.8 34.5 34.3 29,,3 29.1 28.8

2 S 41.6 53.4 65.9 69,,5 81.3 93.6

R 41.6 41.3 40.9 35.,8 35.5 35.2

3 S 53.1 68.2 84.3 87. 9 92.1 106.0

R 53.1 52.6 52.0 45. 0 40.2 39.8

4 S 54.4 69.8 86.3 103. 6 107.8 124.3

R 54.4 53.9 53.3 52. 8 46.8 46.3

5 S 62.8 80.7 99.8 119. 8 124.1 143.1

R 62.8 62.1 61.4 60. 7 53.6 53.0

6 S 71.0 91.3 112.9 135. 6 140.0 161.5

R 71.0 70.2 69.3 68. 4 60.1 59.4

8 S 86.0 110.7 120.4 144. 6 151.8 175.3

R 86.0 84.8 74.0 73. 0 65.3 64.5

10 S 101.5 130.9 141.9 152. 5 178.5 187.3

R 101.5 100.0 86.8 77.21 76.2 69.0

12 S 115.7 130.7 144.2 173. 3 183.6 212.1

R 115.7 100.0 88.3 87. 1 78.3 77.3

14 S 124.7 140.2 154.5 185. 7 196.7 227.4

R 124.7 107.1 94.3 92. 9 83.5 82.2

16 S 119.9 154.8 170.7 185. 7 217.4 230.1

R 119.9 117.9 103.8 93. 0 91.6 83.2

18 S 130.8 150.7 186.7 203. 0 237.8 251.6

R 130.8 114.9 113.0 101. 1 99.4 90.2

Note: Energy Cost = $4.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-2.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $4/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 250 300 350 400 450 500

1 1.5 1.5 1.5 2.0 2.0 2.0

2 2.0 2.0 2.0 2.5 2.5 2,5

3 2.0 2.0 2.0 2.5 3.0 3.0

4 2.5 2.5 2.5 2.5 3.0 3.0

5 2.5 2.5 2.5 2.5 3.0 3.0

6 2.5 2.5 2.5 2.5 3.0 3.0

8 2.5 2.5 3.0 3.0 3.5 3.5

MO 2.5 2.5 3.0 3.5 3.5 4.0

12 2.5 3.0 3.5 3.5 4.0 4.0

14 2.5 3.0 3.5 3.5 4.0 4.0

16 3.0 3.0 3.5 4.0 4.0 4.5

18 3.0 3.5 3.5 4.0 4.0 4.5

Note; Energy Cost = $4.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-3.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $5/MBtu

Pipe

Size Pipe

Proc

( inch) Type 250 300

1 S 34.8 38.3

R 34.8 29.7

2 S 41.6 46.9

R 41.6 36.3

3 S 53.1 59.3

R 53.1 45.8

4 S 54.4 69.8

R 54.4 53.9

5 S 62.8 80.7

R 62.8 62.1

6 S 71.0 91.3

R 71.0 70.2

8 S 75.7 97.3

R 75.7 74.9

10 S 89.1 114.7

R 89.1 88.0

12 S 101.4 116.6

R 101.4 89.5

14 S 108.6 124.8

R 108.6 95.7

16 S 106.9 137.9

R 106.9 105.4

18 S 116.7 150.7

R 116.7 114.9

ss Fluid Temperature (F)

350 400 450 500

47 .3 56 .7 66 .3 68 .2

29 .5 29 .3 29 .1 25 .9

57 .9 69 .5 81 .3 84 .5

36 .1 35 .8 35 .5 32 .0

73 .3 78 .7 92 . 1 106 .0

45 .4 40 .5 40 .2 39 .8

86 .3 92 .2 107 .8 124 .3

53 .3 47 .2 46 .8 46 .3

99 .8 106 .1 124 .1 143 .1

61 .4 54 .1 53 .6 53 .0

112,.9 119 .6 126 .2 145 .5

69,.3 60,.8 54 .6 54 . 1

120,.4 129,.8 138 .5 159 .7 74,.0 66,.0 59,.9 59 .3

127,,0 152,.5 162,,5 172..1 78,,1 77.,2 6Q,,8 63.,8

144. 2 156. 9 183,,6 194.,5

88. 3 79. 3 78. 3 71

.

,4

154. 5 168. 1 196. 7 208. 3 94, 3 84. 7 83. 5 76. 0

154. 5 170. 1 199. 1 230. 1 94. 3 85. 6 84. 5 83. 2

168. 8 185. 8 217. 5 232. 4

102. 7 93. 1 91. 7 84. 1

Note; Energy Cost = $5.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-3.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $5/MBtu

Pipe Process Fluid Temnerature (F)

Size

( inch) 250 300 350 400 450 500

1 1.5 2.0 2.0 2.0 2.0 2.5

2 2.0 2.5 2.5 2.5 2.5 3.0

3 2.0 2.5 2.5 3.0 3.0 3.0

4 2.5 2.5 2.5 3.0 3.0 3.0

5 2.5 2.5 2.5 3.0 3.0 3.0

6 2.5 2.5 2.5 3.0 3.5 3.5

8 3.0 3.0 3.0 3.5 4.0 4.0

TLO 3.0 3.0 3.5 3.5 4.0 4.5

12 3.0 3.5 3.5 4.0 4.0 4.5

14 3.0 3.5 3.5 4.0 4.0 4.5

16 3.5 3.5 4.0 4.5 4.5 4.5

18 3.5 3.5 4.0 4.5 4.5 5.0

Note: Energy Cost = $5.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-4.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water SupplyPipe (S) and Return Pipe (R) for Energy Cost of $6/MBtu

Pipe Process Fluid Temneirature (F)

Size Pipe - (inch), Typ.e 250 300 350 40C) 450 500

1 S 29. 9 38. 3 47. 3 50. 7 59 .3 68. 2 R 29. 9 29. 7 29. 5 26. 3 26 .1 25. 9

2 S 36. 6 46. 9 57. 9 62. 8 73 . 5 84. 5 R 36. 6 36. 3 36. 1 32. 5 32 .3 32. 0

3 S 46. 2 59. 3 65. 6 78. 7 92 .1 106. 0

R 46. 2 45. 8 40. 8 40. 5 40 .2 39. 8

4 S 54. 4 69. 8 76. 8 92. 2 107 .a 112. 8

R 54. 4 53. 9 47. 7 47. 2 46 .8 42. 4

5 S 62. 8 71. 5 88. 4 106. 1 124 .1 129. 4

R 62. 8 55. 2 54. 7 54. 1 53 .6 48. 3

6 S 71. 0 80. 6 99. 7 119. 6 126 .2 145. 1 R 71. 0 62. 2 61. 5 60. 8 54 .6 54. 1

8 S 75. 1 87. 4 108. 1 129. 8 138 .5 159. 7 R 75. 7 67. 4 66. 7 66. 0 59 .9 59. 3

10 S 89. 1 102. 7 127. 0 138. 7 149 .2 172. 1 R 89. 1 79. 0 78. 1 70. 6 64 .5 63. 8

12 S 90. 6 116. 6 130. 7 156. 9 168 .5 180. 2 R 90. 6 89. 5 80. 3 79. 3 72 .3 66. 6

14 S 96. 9 124. 8 139. 9 168. 1 180 .3 192. 8

R 96. 9 95. 7 85. 8 84. 7 77 .0 70. 9

16 S 106. 9 124. 8 141. 6 170. 1 199 . 1 212. 7 R 106. 9 95. 7 86. 8 85. 6 84 .5 77. 6

18 S 116. 7 136. 4 154. 6 171

.

8 201 .1 216. 5 R 116. 7 104. 3 94. 5 86. 5 85,.4 78. 9

Note: Energy Cost = $6.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-4.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $6/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 250 300 350 400 450 500

1 2.0 2.0 2.0 2.5 2.5 2.5

2 2.5 2.5 2.5 3.0 3.0 3.0

3 2.5 2.5 3.0 3.0 3.0 3.0

4 2.5 2.5 3.0 3.0 3.0 3.5

5 2.5 3.0 3.0 3.0 3.0 3.5

6 2.5 3.0 3.0 3.0 3.5 3.5

8 3.0 3.5 3.5 3.5 4.0 4.0

-10 3.0 3.5 3.5 4.0 4.5 4.5

12 3.5 3.5 4.0 4.0 4.5 5.0

14 3.5 3.5 4.0 4.0 4.5 5.0

16 3.5 4.0 4.5 4.5 4.5 5.0

18 3.5 4.0 4.5 5.0 5.0 5.5

Note: Energy Cost = $6.00/NBtu

Return Pipe Temperature = 250 F
TABLE C-5.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $7/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Type 250 300 350 400 450 500

1 S 29 .9 38 .3 47.3 50 .7 59 .3 68 .2

R 29 .9 29 .7 29.5 26 .3 26 .1 25 .9

2 S 36 .6 46 .9 57.9 62 .8 73 .5 84 .5

R 36 .6 36 .3 36.1 32 .5 32 .3 32 .0

3 S 46 .2 53 .1 65.6 78 .7 92 . 1 106 .0

R 46 .2 41 .1 40.8 40 .5 40 .2 39 .8

4 S 54 .4 62 .2 76.8 92 .2 98 .0 112 .8

R 54 .4 48 .1 47.7 47 .2 42 .8 42 .4

5 S 62 .8 71 .5 88.4 106 .1 112 .3 129 .4

R 62 .8 55 .2 54.7 54 .1 48 .8 48 .3

6 S 71,.0 80 .6 99.7 107,.9 115 .6 133 .2

R 71,.0 62 .2 6-1.5 55,.2 50..3 49 .9

8 S 75..7 87,.4 108.1 118,.4 127,.9 147,.4

R 75,.7 67,.4 66.7 66,.5 55,.7 55,.1

10 S 79,,9 102,,7 115.5 127,.6 149,.2 159,.7 R 79.,9 79,.0 71.4 65,,2 64,,5 59.,5

12 S 82.,1 105,,6 130.7 144.,0 156.,2 168.,4

R 82. 1 81.,3 80.3 73. 1 67. 3 62.,5

14 S 87. 9 113. 1 139.9 154. 1 167. 0 180. 0

R 87. 9 86. 9 85.8 78. 0 71. 7 66. 5

16 S 96. 9 114. 4 141.6 170. 1 184. 1 198. 4

R 96. 9 87. 9 86.8 85. 6 78. 6 72. 8

18 S 105. 7 124. 9 143.0 171. 8 187. 4 216. 5 R 105. 7 95. 8 87.7 86. 5 80. 0 78. 9

Note; Energy Cost = $7.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-5.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $7/MBtu

Pipe Process Fluid Temnerature (F)

Size

linch) 250 300 350 400 450 500

1 2.0 2.0 2.0 2.5 2.5 2.5

2 2.5 2.5 2.5 3.0 3.0 3.0

3 2.5 3.0 3.0 3.0 3.0 3.0

4 2.5 3.0 3.0 3.0 3.5 3.5

5 2.5 3.0 3.0 3.0 3.5 3.5

6 2.5 3.0 3.0 3.5 4.0 4.0

8 3.0 3.5 3.5 4.0 4.5 4.5

-10 3.5 3.5 4.0 4.5 4.5 5.0

12 4.0 4.0 4.0 4,5 5.0 5.5

14 4.0 4.0 4.0 4.5 5.0 5.5

16 4.0 4.5 4.5 4.5 5.0 5.5

18 4.0 4.5 5.0 5.0 5.5 5.5

Note; Energy Cost = $7.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-6.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $8/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Type 250 300 350 400 450 500

1 S 29..9 34. 2 42. 3 50,,7 59,,3 62. 5 R 29,.9 26.,6 26. 4 26,.3 26., 1 23. 9

2 S 36.,6 42. 4 52. 4 62.,8 73,,5 84. 5 R 36,,6 32.,9 32. 7 32.,5 32.,3 32. 0

3 S 41..4 53.,1 65. 6 78..7 92.,1 106. 0

R 41,,4 41,, 1 40. 8 40,.5 40,.2 39. 8

4 S 48..5 62,.2 69. 8 83,.8 98 .0 112. 8 R 48,.5 48,, 1 43.,5 43,.1 42 .8 42.,4

5 S 55,.7 71.,5 80.,0 96,.0 112 .3 118.,8

R 55,.7 55..2 49.,7 49 .2 48 .8 44.,7

6 S 62,.8 72..7 89.,9 107,.9 115 .6 133.,2

R 62 .8 56,,2 55.,7 55,.2 50 .3 49.,9

8 S 68 .1 79,,8 98.,7 118 .4 127 .9 147.,4

R 68 .1 61,,7 61..1 60 .5 55 .7 55.,1

10 S 79,.9 93,,5 106.,3 127,.6 149 .2 159.,7

R 79,.9 72.,1 65.,8 65,.2 64 .5 59.,5

12 S 82.. 1 105,.6 119. 9 133..5 156,.2 168. 4

R 82.,1 81..3 74. 0 68..0 67,.3 62. 5

14 S 87,.9 113.,1 128. 3 142,,8 156,,0 180. 0

R 87,.9 86. 9 78. 9 72.,6 67.,3 66. 5

16 S 88.,9 114. 4 131. 0 157. 4 171.,8 186. 2 R 88. 9 87. 9 80. 6 79. 6 73. 7 68. 7

18 S 97. 0 115. 6 133. 3 160. 1 187. 4 203. 0

R 97. 0 88. 8 82. 0 81. 0 80. 0 74. 5

Note: Energy Cost = $8.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-6.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $8/MBtu

Pipe Process Fluid Temneraturei (F)

Size

( inch) 250 300 350 400 450 500

1 2.0 2.5 2.5 2.5 2.5 3.0

2 2.5 3.0 3.0 3.0 3.0 3.0

3 3.0 3.0 3.0 3.0 3.0 3.0

4 3.0 3.0 3.5 3.5 3.5 3.5

5 3.0 3.0 3.5 3.5 3.5 4.0

6 3.0 3.5 3.5 3.5 4.0 4.0

8 3.5 4.0 4.0 4.0 4.5 4.5

-10 3.5 4.0 4.5 4.5 4.5 5.0

12 4.0 4.0 4.5 5.0 5.0 5.5

14 4.0 4.0 4.5 5.0 5.5 5.5

16 4.5 4.5 5.0 5.0 5.5 6.0

18 4.5 5.0 5.5 5.5 5.5 6.0

Note: Energy Cost = $8.00/MBtu

Return Pipe Temperature = 250 F
TABLE- C-7 .a

Maximum Allowable Heat Losses (Btu/h’ft) from Hot Water SupplyPipe (S) and Return Pipe (R) for Energy Cost of $9/MBtu

Pipe Process Fluid Tem-perature CF)

Size Pipe

( inch) Typ_e 250 300 350 400 450 500

1 S 26 .8 34.2 42 .3 46 .5 54 .4 62 .5

R 26 .8 26.6 26 .4 24 .2 24 .0 23 .9

2 S 36 .6 42.4 52 .4 62 .8 73 .5 84 .5

R 36 .6 32.9 32 .7 32 .5 32 .3 32 .0

3 S 41 .4 53.1 65 .6 78 .7 84 . 1 96 .8

R 41,.4 41.1 40 .8 40 .5 36 .9 36 .6

4 S 48 .5 62.2 69 .8 83 .8 98 .0 112 .8

R 48,.5 48.1 43 .5 43 .1 42 .8 42 .4

5 S 55,,7 71.5 80,.0 96,.0 103,.2 118 .8

R 55..7 55.2 49,.7 49,.2 45,.1 44,.7

6 S 62..8 72.7 89,.9 107,,9 115,.6 123.,5

R 62..8 56.2 55,.7 55,.2 50,.3 46..5

8 S 68.,1 79.8 98,,7 109,,4 127.,9 137,,4

R 68., 1 61.7 61,.1 56,,2 55,.7 55,,7

10 S 72.,8 93.5 106.,3 127..6 138.,6 149.,5

R 72. 8 72.1 65.,8 65.,2 60. 1 55.,9

12 S 82. 1 97.0 111. 2 133. 5 146. 0 168. 4

R 82. 1 74.7 68. 7 68. 0 63. 2 62. 5

14 S 87. 9 103.7 118. 9 133. 4 156. 0 169. 2 R 87. 9 79.8 73. 4 68. 0 67. 3 62. 8

16 S 88. 9 114.4 131. 0 146. 8 171. 8 186. 2 R 88. 9 87.9 80. 6 74. 6 73. 7 68. 7

18 S 97. 0 115.6 133. 3 160. 1 187. 4 203. 0

R 97. 0 88.8 82. 0 81. 0 80. 0 74. 5

Note: Energy Cost = $9.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-7.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $9/MBtu

Pipe Process Fluid Temnerature: (F)

Size

( inch) 250 300 350 400 450 500

1 2.5 2.5 2.5 3.0 3.0 3.0

2 2.5 3.0 3.0 3.0 3.0 3.0

3 3.0 3.0 3.0 3.0 3.5 3.5

4 3.0 3.0 3.5 3.5 3.5 3.5

5 3.0 3.0 3.5 3.5 4,0 4.0

6 3.0 3.5 3.5 3.5 4.0 4.5

8 3.5 4.0 4.0 4.5 4.5 5.0

-10 4.0 4.0 4.5 4.5 5.0 5.5

12 4.0 4.5 5.0 5.0 5.5 5.5

14 4.0 4.5 5.0 5.5 5.5 6.0

16 4.5 4.5 5.0 5.5 5.5 6.0

18 4.5 5.0 5.5 5.5 5.5 6.0

Note: Energy Cost = $9.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-8.a

Maximum Allowable Heat Losses (Btu/h-ft) from Hot Water SupplyPipe (S) and Return Pipe (R) for Energy Cost of $10/MBtu

Pipe Process Fluid Temperature (F)

Size Pipe

( inch) Ty^e 250 300 350 400 450 500

1 S 26 .8 34 .2 38 .8 46 .5 54 .4 62 .5

R 26 .8 26 .6 24 .3 24 .2 24 .0 23 .9

2 S 36 .6 42 .4 52 .4 62 .8 73 .5 77 .9

R 36 .6 32 .9 32 .7 32 .5 32 .3 29 .7

3 S 41 .4 53 .1 65 .6 78 .7 84 .1 96 .8

R 41 .4 41 .1 40 .8 40 .5 36 .9 36 .6

4 S 48 .5 56 .5 69 .8 83 .8 98 .0 112 .8

R 48 .5 43 .8 43 .5 43 .1 42 .8 42 .4

5 S 55 .7 64 .7 80 .0 88 .2 103 .2 118 .8

R 55 .7 50 .1 49 .7 45 .4 45 .1 44 .7

6 S 56 .7 72 .7 89 .9 98 .9 107 .3 123 .5

R 56 .7 56 .2 55 .7 50 .•8 46 .9 46 .5.

8 S 62 .2 73,.8 91 .2 109,.4 119,.3 137 .4

R 62,.2 57,.1 56,.6 56,.2 52,.1 51 .7

10 S 72,.8 86,.0 98,.7 118,.5 129,.8 149,.5 R 72..8 66,,4 61,,2 60,,7 56,.5 55,,9

12 S 75,,5 97,,0 111,.2 124.,8 146,,0 158,,4

R 75,,5 74.,7 68.,7 63.,8 63,,2 59,,1

14 S 80. 7 103. 7 118.,9 133. 4 156. 0 169. 2 R 80. 7 79. 8 73. 4 68. 0 67. 3 62. 8

16 S 88. 9 114. 4 131. 0 146. 8 161. 3 186. 2 R 88. 9 87. 9 80. 6 74. 6 69. 5 68. 7

18 S 89. 8 115. 6 133. 3 150. 3 175. 8 203. 0

R 89. 8 88. 8 82. 0 76. 3 75. 4 74. 5

Note; Energy Cost = $10.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-8.b

Economic Insulation Thickness (inch) for Supplyand Re turn Pipes for Energy Cost of $ 10/MB tu

Pipe Process Fluid Temoerature (F)

Size

( inch) 250 300 350 400 450 500

1 2.5 2.5 3.0 3.0 3.0 3.0

2 2.5 3.0 3.0 3.0 3.0 3.5

3 3.0 3.0 3.0 3.0 3.5 3.5

4 3.0 3.5 3.5 3.5 3.5 3.5

5 3.0 3.5 3.5 4.0 . 4.0 4.0

6 3.5 3.5 3.5 4.0 4.5 4.5

8 4.0 4.5 4.5 4.5 5.0 5.0

-10 4.0 4.5 5.0 5.0 5.5 5.5

12 4.5 4.5 5.-0 5.5 5.5 6.0

14 4.5 4.5 5.0 5.5 5.5 6.0

16 4.5 4.5 5.0 5.5 6.0 6.0

18 5.0 5.5 5.5 6.0 6.0 6.0

Note: Energy Cost = $10.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-9.a

Maximum Allowabie Heat Losses (Btu/h-ft) from Hot Water SupplyPipe (S) and Return Pipe (R) for Energy Cost of $ll/MBtu

Pipe Process; Fluid Tempesrature (F)

Size Pipe

( inch) TyP-e 250 300 350 400 450 500

1 S 26 .8 34.2 38 .8 46,.5 54 .4 62,.5 R 26 .8 26.6 24 .3 24,,2 24 .0 23,.9

2 S 33 .1 42.4 52 .4 62,,8 67 .7 77,.9 R 33,.1 32.9 32 .7 32.,5 29 .9 29,.7

3 S 41.,4 53.1 65 .6 78,,7 84 .1 96,,8

R 41,.4 41.1 40 .8 40.,5 36 .9 36,,6

4 S 44,, 1 56.5 69 .8 83. 8 92 .8 112.,8

R 44,,1 43.8 43 .5 43. 1 42 .8 42,,4

5 S 50.,5 64.7 73 .5 88, 2 103 .2 118,.8 R 50,,5 50.1 45 .8 45. 4 45 .1 44,,7

6 S 56.,7 72.7 82 .4 98. 9 107 .3 123..5 R 56,,7 56.2 51 .2 50. 8 46 .9 46,,5

8 S 62.,2 73.8 91 .2 102. 0 119 .3 129,,0

R 62.,2 57.1 56 .6 52.,5 52 . 1 48,,7

10 S 72,,8 86.0 98 .7 110.,9 129 .8 140,,9

R 72..8 66.4 61 .2 57.,0 56 .5 52,.9

12 S 75,.5 90.0 104 .0 124. 8 137 .4 158,.4

R 75,,5 69.4 64 .4 63.,8 59 .7 59,,1

14 S 80..7 96.2 111 .1 133,,4 146 .7 169,,2

R 80,,7 74.1 68 J 68. 0 63 .5 62,,8

16 S 82..4 105.9 122 .3 137. 9 161 .3 186,.2 R 82,,4 81.5 75 .4 70. 3 69 .5 68.,7

18 S 83..8 107.8 133 .3 150. 3 175 .8 203.,0

R 83,,8 82.9 82 .0 76. 3 75 .4 • 74. 5

Note: Energy Cost = $11.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-9.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $ll/MBtu

Pipe Process Fluid Temperature (F)

Size

(inch) 250 300 350 400 450 500

1 2,5 2.5 3,0 3.0 3.0 3.0

2 3.0 3.0 3.0 3.0 3.5 3.5

3 3.0 3.0 3.0 3.0 3.5 3.5

4 3.5 3.5 3.5 3.5 3.5 3.5

5 3.5 3.5 4.0 4.0 4.0 4.0

6 3.5 3.5 4.0 4.0 4.5 4.5

8 4.0 4.5 4.5 5.0 5.0 5.5

-10 4.0 4.5 5.0 5.5 5.5 6.0

12 4.5 5.0 5.5 5.5 6.0 6.0

14 4.5 5.0 5.5 5.5 6.0 6.0

16 5.0 5.0 5.5 6.0 6.0 6.0

18 5.5 5.5 5.5 6.0 6.0 6.0

Note; Energy Cost = $11.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-lO.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $12/MBtu

Pipe Process> Fluid Temti(srature (F)

Size Pipe

( inch) Type 250 300 350 400 450 500

1 S 24.6 31 .4 38 .8 46 .5 54 .4 62 .5

R 24.6 24 .4 24 .3 24 .2 24 .0 23 .9

2 S 33.1 42 .4 52 .4 57 .9 67 .7 77 .9

R 33.1 32 .9 32 .7 30 .0 29 .9 29 .7

3 S 41.4 53,.1 65 .6 71,.9 84 .1 89 .7 R 41.4 41,,1 40 .8 37,.2 36 .9 34 .1

4 S 44.1 56,.5 69 .8 83 .8 98 .0 104,,0

R 44.1 43.,8 43,.5 43,.1 42 .8 39,.3

5 S 50.5 64..7 73,.5 88,,2 103 .2 118,.8 R 50.5 50.,1 45,,8 45,,4 45 .1 44,,7

6 S 56.7 66.,7 82,,4 91.,7 107 .3 115,,6

R 56.7 51. 6 51,,2 47.,3 46 .9 43,,7

8 S 62.2 73. 8 91..2 • 102.,0 119 .3 129,,0

R 62.2 57. 1 56.,6 52.,5 52 .1 48,,7

10 S 67.0 79. 9 98.,7 110. 9 129 .8 140.,9

R 67.0 61. 8 61.,2 57. 0 56 .5 52. 9

12 S 70.1 90. 0 104.,0 117. 5 137 .4 158.,4

R 70.1 69. 4 64.,4 60. 2 59 .7 59. 1

14 S 74.8 96. 2 111.,1 125. 4 146 .7 169. 2 R 74.8 74. 1 68.,7 64. 1 63 .5 62. 8

16 S 82.4 98. 9 122. 3 137. 9 161,.3 186. 2 R 82.4 76. 2 75. 4 70. 3 69 .5 68. 7

18 S 83.8 107. 8 133. 3 150. 3 175,.8 203. 0

R 83.8 82. 9 82. 0 76. 3 75,.4 74. 5

Note: Energy Cost = $12.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-lO.b

Note

:

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $12/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 250 300 350 400 450 500

1 3.0 3.0 3.0 3.0 3.0 3.0

2 3.0 3.0 3.0 3.5 3.5 3.5

3 3.0 3.0 3.0 3.5 3.5 4.0

4 3.5 3.5 3.5 3.5 3.5 4.0

5 3.5 3.5 4.0 4.0 4.0 4.0

6 3.5 4.0 4.0 4.5 4.5 5.0

8 4.0 4.5 4.5 5.0 5.0 5.5

10 4.5 5.0 5.0 5.5 5.5 6.0

12 5.0 5.0 5.5 6.0 6.0 6.0

14 5.0 5.0- 5.5 6.0 6.0 6.0

16 5.0 5.5 5.5 6.0 6.0 6.0

18 5.5 5.5 5.5 6.0 6.0 6.0

Energy Cost = $12.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-ll,a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $13/MBtu

Pipe Process; Fluid Temnerature (F)

Size Pipe

C inch) Tvne 250 300 350 400 450 500

1 S 24 .6 31.4 38,.8 46,.5 54 .4 62,,5

R 24 .6 24.4 24,.3 24,.2 24 .0 23,.9

2 S 33 .1 42.4 52,.4 57,.9 67 .7 77,.9 R 33 .1 32.9 32,.7 30 .0 29 .9 29,.7

3 S 41,.4 53.1 65,.6 71,.9 84 .1 89 .7 R 41 .4 41.1 40,.8 37,.2 36 .9 34 . 1

4 S 44 . 1 56.5 69 .8 83 .8 98 .0 104 .0

R 44 .1 43.8 43,.5 43 . 1 42 .8 39 .3

5 S 50 .5 59.5 73,.5 88 .2 103 .2 118 .8

R 50 .5 46.1 45,.8 45 .4 45 .1 44 .7

6 S 56 .7 66.7 76,.4 91 .7 107 .3 115 .6

R 56 .7 51.6 47,.6 47 .3 46 .9 43 .7

8

' S 62 .2 73.8 85,.1 102 .0 112 . 1 129 .0

R 62,.2 57.1 53,.0 52 .5 49 .1 48 .7

10 S 67,.0 79.9 92,.5 110,.9 122 .3 140 .9

R 67,.0 61.8 57,.4 57,.0 53 .4 52,.9

12 S 70..1 84.1 104,,0 117,.5 137 .4 158,.4

R 70.,1 65.0 64,,4 60,,2 59 .7 59,. 1

14 S 74,,8 89.8 104. 5 125.,4 146 .7 169.,2

R 74.,8 69.3 64. 7 64. 1 63 .5 62. 8

16 S 76. 9 98.9 114. 9 137. 9 161,.3 186. 2 R 76. 9 76.2 71. 0 70. 3 69,,5 68. 7

18 S 83. 8 107.8 125. 1 150. 3 175.,8 203. 0

R • 83. 8 82.9 77. 1 76. 3 75.,4 74. 5

Note: Energy Cost = $13.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-ll.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $13/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 250 300 350 400 450 500

1 3.0 3.0 3.0 3.0 3.0 3.0

2 3.0 3.0 3.0 3.5 3.5 3.5

3 3.0 3.0 3.0 3.5 3.5 4.0

4 3.5 3.5 3.5 3.5 3.5 4.0

5 3.5 4.0 4.0 4.0 4.0 4.0

6 3.5 4.0 4.5 4.5 4.5 5.0

8 4.0 4.5 5.0 5.0 5.5 5.5

10 4.5 5.0 5.5 5.5 6.0 6.0

12 5.0 5.5 5.5 6.0 6.0 6.0

14 5.0 5.5 6.0 6.0 6.0 6.0

16 5.5 5.5 6.0 6.0 6.0 6.0

18 5.5 5.5 6.0 6.0 6.0 6.0

Note: Energy Cost = $13.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-12.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water SupplyPipe (S) and Return Pipe (R) for Energy Cost of $14/MBtu

Pipe Process, Fluid Temoerature (F)

Size Pipe

{ inch) Type 250 300 350 400 450 500

1 S 24,.6 31,,4 38,.8 46..5 54 .4 62,,5

R 24,.6 24,.4 24,.3 24.,2 24 .0 23,,9

2 S 33,,1 42,,4 48,.3 57,,9 67 .7 77.,9

R 33,,1 32.,9 30,.2 30,,0 29 .9 29. 7

3 S 41,,4 53.,1 60.,0 66,,7 78 .0 89.,7

R 41.,4 41. 1 37.,4 34.,6 34 .3 34.,1

4 S 44.,1 56. 5 69..8 77.,3 90 .4 104. 0

R 44,,1 43. 8 43.,5 39.,9 39 .6 39.,3

5 S 50.,5 59. 5 73.,5 88.,2 103 .2 118. 8 R 50.,5 46. 1 45,,8 45.,4 45 .1 44.,7

6 S 52,,0 61. 9 76,,4 91..7 107 .3 115.,6

. R 52.,0 48.,0 47,,6 47..3 46 .9 43.,7

8 S 57,,5 68.,8 85,.1 95.,8 112 . 1 121.,9

R 57,,5 53.,4 53.,0 49.,5 49 . 1 46,,1

10 S 62,,3 74.,8 92,,5 104.,6 122 .3 140,,9

R 62,,3 57.,9 57,.4 53,.8 53 .4 52.,9

12 S 65,,5 84.,1 97..9 117,,5 137 .4 158,,4

R 65,,5 65.,0 60,.7 60,,2 59 .7 59., 1

14 S 70,,0 89. 8 104,,5 125.,4 146 .7 169.,2

R 70.,0 69. 3 64,,7 64.,1 63 .5 62. 8

16 S 76.,9 98. 9 114,,9 137.,9 161 .3 186. 2 R 76.,9 76. 2 71.,0 70. 3 69 .5 68. 7

18 S 83. 8 107. 8 125.,1 150. 3 175 .8 203. 0

R 83. 8 82. 9 77. 1 76. 3 75 .4 74. 5

Note: Energy Cost = $14.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-12.b

Note

:

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $14/MBtu

Pipe Process Fluid Temperature (F)

Size

( inch) 250 300 350 400 450 500

1 3.0 3.0 3.0 3.0 3.0 3.0

2 3.0 3.0 3.5 3.5 3.5 3.5

3 3.0 3.0 3.5 4.0 4.0 4.0

4 3.5 3.5 3.5 4.0 4.0 4.0

5 3.5 4.0 4.0 4.0 4.0 4.0

6 4.0 4.5 4.5 4.5 4.5 5.0

8 4.5 5.0 5.0 5.5 5.5 6.0

-10 5.0 5.5 5.5 6.0 6.0 6.0

12 5.5 5.5 6.0 6.0 6.0 6.0

14 5.5 5.5 6;0 6.0 6.0 6.0

16 5.5 5.5 6.0 6.0 6.0 6.0

18 5.5 5.5 6.0 6.0 6.0 6.0

Energy Cost = $14.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-13.a

Maximum Allowable Heat Losses (Btu/h'ft) from Hot Water Supply

Pipe (S) and Return Pipe (R) for Energy Cost of $15/MBtu

Pipe Process Fluid Temptsrature (F)

Size Pipe

( inch) Tvne 250 300 350 400 450 500

1 S 24 .6 31 .4 38 .8 46 .5 54 .4 62 .5

R 24 .6 24 .4 24 .3 24 .2 24 .0 23 .9

2 S 33 .1 42 .4 48 .3 57 .9 67 .7 77 .9

R 33 . 1 32 .9 30 .2 30 .0 29 .9 29 . 7

3 S 41,.4 53 .1 60 .0 66 .7 78 .0 89 . 7 R 41,.4 41 .1 37 .4 34 .6 34 .3 34 . 1

4 S 44.. 1 56 .5 69 .8 77,.3 90 .4 104 .0

R 44., 1 43,.8 43,.5 39,.9 39 .6 39 .3

5 S 50,.5 59,.5 73,,5 88,.2 103 .2 118,.8 R 50.,5 46,,1 45,,8 45,,4 45 .1 44,.7

6 S 52. 0 61,,9 76.,4 91..7 107 .3 115,,6

R 52. 0 48.,0 47.,6 47.,3 46 .9 43..7

8 S 57. 5 68.,8 85. 1 95. 8 112,.1 121.,9

R 57. 5 53. 4 53. 0 49. 5 49,.1 46., 1

10 S 62. 3 74. 8 92. 5 104. 6 122,.3 140. 9 R 62. 3 57. 9 57. 4 53. 8 53..4 52. 9

12 S 65. 5 84. 1 97. 9 117. 5 137.,4 158. 4

R 65. 5 65. 0 60. 7 60. 2 59,.7 59. 1

14 S 70. 0 89. 8 104. 5 125. 4 146.,7 169. 2 R 70. 0 69. 3 64. 7 64. 1 63.,5 62. 8

16 S 76. 9 92. 9 114. 9 137. 9 161.,3 186. 2 R 76. 9 71. 7 71. 0 70. 3 69. 5 68. 7

18 S 83. 8 101. 2 125. 1 150. 3 175. 8 203. 0

R 83. 8 78. 0 77. 1 76. 3 75. 4 74. 5

Note: Energy Cost = $15.00/MBtu

Return Pipe Temperature = 250 F
TABLE C-13.b

Economic Insulation Thickness (inch) for Supply

and Return Pipes for Energy Cost of $15/MBtu

Pipe Process Fluid Temperature! (F)

Size

Cinch) 250 300 350 400 450 500

1 3.0 3.0 3.0 3.0 3.0 3.0

2 3.0 3.0 3.5 3.5 3.5 3.5

3 3.0 3.0 3.5 4.0 4.0 4.0

4 3.5 3.5 3.5 4.0 4.0 4.0

5 3.5 4.0 4.0 4.0 4.0 4.0

6 4.0 4.5 4.5 4.5 4.5 5.0

8 4.5 5.0 5.0 5.5 5.5 6.0

-10 5.0 5.5 5.5 6.0 6.0 6.0

12 5.5 5.5 6.0 6.0 6.0 6.0

14 5.5 5.5 6.0 6.0 6.0 6.0

16 5.5 6.0 6.0 6.0 6.0 6.0

18 5.5 6.0 6.0 6.0 6.0 6.0

Note: Energy Cost = $15.00/MBtu

Return Pipe Temperature = 250 F
NBS-114A (REV. 2-8C)

1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publication Date NBSIR 87 3617

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See instructions)

4. TITLE and subtitle

Calculations of Maximum Allowable Heat Losses for Various

Shallow Trench Heat Distribution Systems

5. AUTHOR(S)

Jin B. Fang

S. PERFORMING ORGANIZATION (If joint or other than NBS. see in struction s)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No,

8. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State. ZIP)

Tri-Service Building Materials Committee

Headquarters, U.S. Army Corps of Engineers

Washington, DC 20314-1000

10. supplementary notes

Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11. abstract (A 200-word or less factual summary of most si gnifi cant information. If document includes a si gn i fi cant

bi bliography or literature survey, mention it here) The calculation of heat losses for shallow trench underground heat distribution

systems was performed using a finite element computer program. The finite element

analysis solved a two.-dimensional steady-state heat transfer problem for two insulated

pipes in a rectangular trench with surrounding soil. A life-cycle cost analysis was performed to determine the cost of construction and annual energy cost associated with

pipe heat loss for underground concrete trench systems of different trench dimensions

and insulated pipe sizes. Procedures for determining the pipe heat losses associated

with the minimum life-cycle cost and the corresponding optimum insulation thickness

for shallow trench distribution systems are presented. Based on the results of the

economic analysis, the maximum allowable heat losses and the insulation thickness for

underground pipes were determined and tabulated for a range of pipe sizes and fluid

temperatures, various levels of fuel costs, and for a known undisturbed earth temperature and soil thermal conductivity.

12. key words (S/x to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) district heating and cooling; finite element method; fuel energy cost; heat loss;

life-cycle cost analysis; pipe insulation thickness; shallow trench; underground heat

distribution system.

13. availability

Unl united For Official Distribution. Do Not Release to NTIS

Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

118

15. Pr $18.95

USCOMM-OC 6043-P80
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