JUMP

Appendix

Test Results

Most tests of radiant barriers have measured the reduction in heat flow through the ceiling caused by adding a radiant barrier. The test results are usually expressed in terms of a percentage ceiling heat flow reduction. Table A1 gives a summary of measured ceiling heat flow reductions for summer conditions when radiant barriers were added in various locations to existing R-19 conventional insulation. Table A2 gives a summary for winter conditions. Table A1 shows that, while there are some variations in the summer data, there is also a good amount of consistency. For winter conditions, there are wider variations in the data and less consistency, but the percentage reductions for winter are less than for summer. Tests by the Tennessee Valley Authority and the Mineral Insulation Manufacturers Association show that increasing the insulation level from R-19 to R-30 instead of installing a radiant barrier reduces the ceiling heat flow by 27 to 33 percent. REMEMBER THAT THE NUMBERS GIVEN IN THE TABLES ARE PERCENTAGE REDUCTIONS FOR THE HEAT FLOW THROUGH THE CEILING; THEY ARE NOT PERCENTAGE REDUCTIONS FOR TOTAL ENERGY USED BY THE AIR-CONDITIONING OR HEATING EQUIPMENT.

Energy Savings Worksheet

If you want a more accurate estimate of your energy savings than the ones given in Tables 3-6, you may use the Worksheet given in this Appendix. Step-by-step instructions are as follows:

  1. Examine air-conditioning unit, determine SEER (for a key to abbreviations, see page 24). Divide SEER by 3.413 to obtain efficiency or COP and enter result in Box A. Typical efficiencies are given in Table X. If SEER is unknown, enter 2.3 in Box A.

  2. Examine heating equipment. Determine whether it is a gas furnace, oil furnace, heat pump, electric furnace, or electric baseboard heating. Determine efficiency, and enter in Box B. Typical efficiencies are given in Table X. If efficiency is unknown, enter 0.65 in Box B.

  3. Obtain cost of electricity, either by examining your electric bills or by contacting your utility. Multiply the cost in cents per kilowatt-hour by 2.93 and enter result in Box C.

  4. Obtain cost of heating fuel, either by examining your fuel bills or by contacting your utility.
    If you heat with gas, multiply the cost in dollars per CCF (or therm) by 10 and enter result in Box D.
    If you heat with oil, multiply the cost in dollars per gallon by 7.15 and enter result in Box D.
    If you heat with electricity (including a heat pump), multiply the cost in cents per kilowatt-hour by 2.93 and enter result in Box D.

  5. Divide the value in Box C by the value in Box A and enter result in Box E.

  6. Divide the value in Box D by the value in Box B and enter result in Box F.

  7. Inspect your attic to determine the type and level of conventional attic insulation, the area of the ceiling, and whether or not the cooling ducts run through the attic.

    The level of insulation may be estimated with the following chart for insulation thickness (in inches) as a function of insulation type and level:

    Type of Insulation R-11 R-19 R-30 R-38
    Fiberglass batts
    Loose-fill fiberglass
    Loose-fill cellulose    		 3.5"
    4.75"
    3.75"    		 6.25"
    8.25"
    6.50"    		 9.75"
    12.75"
    10.50"    		 12.5"
    16"
    13"

    The area of the ceiling is determined by estimating the length and width (in feet) of the ceiling and multiplying these two values together. Enter this value in Box 1.

  8. a. If you plan to install a radiant barrier (RB)
    Go to Table Y1. Locate a city that is near your location and then read off the value for that city for the level of insulation in your attic. Then multiply this value by one of the following factors depending upon the type of radiant barrier you plan to install, and enter the result in Box 2:
    Radiant Barrier Description Configuration Factor
    For low range of values for dusty attic floor RB 0.16
    For high range of values for dusty attic floor RB 0.65
    For RB attached to rafter bottoms, and with no ducts in attic 0.78
    For RB attached to rafter bottoms, and with ducts in attic,
    - and with R-11 conventional attic insulation 0.98
    - or with R-19 conventional attic insulation 1.07
    - or with R-30 conventional attic insulation 1.15
    - or with R-38 conventional attic insulation 1.22
    For RB draped over tops of rafters or attached to roof deck,
    - and with no ducts in attic 0.68
    For RB draped over tops of rafters or attached to roof deck, and with ducts in attic,
    - and with R-11 conventional attic insulation 0.86
    - or with R-19 conventional attic insulation 0.93
    - or with R-30 conventional attic insulation 1.01
    - or with R-38 conventional attic insulation 1.07

    b. If you plan to install more insulation.
    Go to Table Y3. Locate a city near your location and read off the value for that city and for the initial and final levels of attic insulation. Note that values in the table may be added in steps. For example, if you start with R-11 insulation and want to go to the R-38 level, add the values for going from R-11 to R-19, for R-19 to R-30, and for R-30 to R-38. Enter the value in Box 2.

  9. a. If you plan to install a radiant barrier.
    Go to Table Y2. Locate the same city that you used for Step 8a and read off the value for that city for the level of insulation in your attic. Then multiply this value by one of the following factors depending upon the type of radiant barrier you plan to install, and enter the result in Box 3:
    RAdiant Barrier Description Configuration Factor
    For low range of values for dusty attic floor RB 0.24
    For high range of values for dusty attic floor RB 0.61
    For RB attached to rafter bottoms 0.88
    For RB draped over tops of rafters or attached to roof deck 0.82

    b. If you plan to install more insulation.
    Go to Table Y4. Locate the same city that you used for Step 8b and read off the value for that city and for the initial and final levels of attic insulation. Note that values in the table may be added in steps. For example, if you start with R-11 insulation and want to go to the R-38 level, add the values for going from R-11 to R-19, for R-19 to R-30, and for R-30 to R-38. Enter the value in Box 3.

  10. Multiply the values in Boxes 1, 2, and E together, and divide the result by 1,000,000. Enter the result in Box 4.

  11. Multiply the values in Boxes 1, 3, and F together, and divide the result by 1,000,000. Enter the result in Box 5.

  12. Add the values in Boxes 4 and 5 together, and enter the result in Box 6. This is the expected savings per year due to adding a radiant barrier or additional attic insulation.

  13. a. If you plan to install a radiant barrier
    Determine the estimated cost for installing a radiant barrier in your home. This may be from a quote, or you may estimate the cost by using the values in Table 1 along with your estimate of the ceiling area. Note that for radiant barriers installed on the rafters or on the roof deck, you will have to estimate the area of the roof and the areas of the gable ends. Enter the estimated cost in Box 7.

    b. If you plan to install additional attic insulation.
    Determine the estimated cost for installing more insulation in your home. This may be from a quote, or you may estimate the cost by using the values in Table 2 along with your estimate of the ceiling area. Enter the estimated cost in Box 7.

  14. Go to Table Z. Locate the census region where you live and read off the value for electricity. Enter this value in Box 8.

  15. Go to Table Z. Locate the census region where you live and read off the value for either electricity, oil, or natural gas, depending upon your heating fuel type. Enter this value in Box 9.

  16. Multiply the value in Box 4 by the value in Box 8. Enter the result in Box 10.

  17. Multiply the value in Box 5 by the value in Box 9. Enter the result in Box 11.

  18. Add the value in Box 10 to the value in Box 11 and enter the result in Box 12.

  19. Compare the value in Box 12 with the value in Box 7. If the value in Box 12 is greater than or equal to the value in Box 7, then the radiant barrier or additional insulation is an economical investment. If the value in Box 12 is less than the value in Box 7, then the radiant barrier or additional insulation is not an economical investment.

  20. A simple payback period may also be determined by dividing the value in Box 7 by the value in Box 6. The result will be the number of years that it takes for the energy savings with the radiant barrier or additional insulation to pay back its initial cost. Note that this procedure is not applicable to the radiant barrier on the attic floor, because the energy savings changes from year to year.

Note: If you are planning to install a radiant barrier on the attic floor on top of the existing attic insulation, you should go through the worksheet twice, using the two factors that are given in Steps 8a and 9a to obtain an estimate of the expected range of energy savings.

Example of Use of Worksheet

I live in Orlando, Florida in a one-level 1800 square foot house. I have a heat pump system that has medium efficiency. My electricity costs 8 cents per kilowatt hour. I have 3.5 inches of fiberglass batt insulation (R-11) in my attic and the air-conditioning ducts are in the attic. A contractor has quoted a price for a radiant barrier installed on the bottoms of my rafters and on the gable ends for $400. Would this be a good investment?

Following the steps outlined in the instructions, the worksheet is filled out. The total present value of energy savings given in Box 12 is $533.14. This value exceeds the quoted cost of the radiant barrier of $400, and thus this would be a good investment.

EXAMPLE

ENERGY SAVINGS ESTIMATE FOR RADIANT
BARRIERS OR ATTIC INSULATION
WORKSHEET

COST OF ENERGY FOR HEATING AND COOLING
Code: (A) (B) (C) (D) (E) (F)
Cooling Equipment Efficiency
(From Table X)		 Heating Equipment Efficiency
(From Table X)		 Cooling Fuel Price
$/Million BTU		 Heating Fuel Price
$/Million BTU		 Cooling Energy Cost
$/Million BTU
[C÷A]		 Heating Energy Cost
$/Million BTU
[D÷B]
2.6 1.9 8x2.93=
23.44		 8x2.93=
23.44		 9.02 12.34

For fuel prices:

Electricity: $/million BTU = ¢/KWH x 2.93
Natural Gas: $/million BTU = ($/therm or $/CCF) x 10
Fuel Oil: $/million BTU = $/gal. x 7.15

ESTIMATED ENERGY SAVINGS

Code: (1) (2) (3) (4) (5) (6) (7)
Ceiling Area, Square Feet Cooling Load Factor
(From Table Y)		 Heating Load Factor
(From Table Y)		 Annual Cooling Savings, $/yr
[(1) x (2) x E] ÷ 1,000,000		 Annual Heating Savings, $/yr
[(1) x (3) x F]÷ 1,000,000		 Total Energy Savings, $/yr
[(4)+(5)]		 Cost for RB or Insulation, $
1800 2575x0.98=
2524		 275x0.88=
242		 40.98 5.38 46.36 400

ESTIMATED LIFE CYCLE PRESENT VALUE SAVINGS
Code: (8) (9) (10) (11) (12)
Cooling Discount Factor
(From Table Z)		 Heating Discount Factor
(From Table Z)		 Present Value Cooling Savings, $
[(4) x (8)]		 Present Value Heating Savings, $
[(5) x (9)]		 Total Present Value Energy Savings, $
[(10) + (11)]
11.50 11.50 471.27 61.87 533.14

Other Sections

Effect of Radiant Barrier on Heating and Cooling Bills
Important Non-Energy Considerations
Installation Procedures
Appendix
Key to Abbreviations
Information Services
About This Fact Sheet

Table 1

Costs for Radiant Barriers Installed by Contractors

Costs per Square Foot of Material*
Type of Application New Construction Existing Home
Attic Floor $0.15 - 0.30 $0.15 - 0.30
Roof: stapled to bottom or faces of rafters $0.15 - 0.30 $0.20 - 0.45
Roof: draped over rafters $0.12 - 0.35 ----
Roof: underside of roof deck $0.12 - 0.30 ----

*The cost figures in this table are the costs per square foot of radiant barrier. Since the total area of the roof and gables is larger than the area of the ceiling, roof applications will require about 7 to 50 percent more material than an attic floor application, depending upon the shape of the roof.

Source: Reflective Insulation Manufacturers Association.

Table 2

Costs for Conventional Attic Insulation Installed by Contractors

R-Value Cost per Square Foot
R-11 $0.27 - 0.30
R-19 $0.38 - 0.47
R-22 $0.48 - 0.51
R-30 $0.54 - 0.68
R-38 $0.68 - 0.95

Note: The higher the R-value, the greater the insulating power.

Source: Residential Construction and Utility Cost data base, developed by NAHB National Research Center, 1986.

Table 3

Present Value Savings for Dusty Radiant Barrier on Attic Floor

(Note: R-11, R-19, R-30, and R-38 refer to the existing level of conventional insulation.)

City Present Value Savings, Dollars per Square Foot of Attic Floor
R-11 R-19 R-30 R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		0.04-0.13
0.05-0.18
0.05-0.17
0.05-0.14
0.04-0.13
0.05-0.15
0.04-0.15
0.05-0.19
0.05-0.17
0.07-0.24
0.03-0.08
0.05-0.18
0.06-0.23
0.04-0.13
0.05-0.21
0.08-0.29
0.04-0.10
0.04-0.11
0.05-0.16
0.06-0.21
0.05-0.18
0.05-0.16
0.05-0.16
0.03-0.08
0.05-0.17
0.06-0.21
0.05-0.15 		0.02-0.06
0.03-0.10
0.02-0.08
0.02-0.06
0.02-0.06
0.02-0.07
0.02-0.07
0.03-0.10
0.02-0.08
0.03-0.12
0.02-0.05
0.02-0.09
0.03-0.12
0.02-0.06
0.03-0.10
0.04-0.14
0.02-0.04
0.02-0.05
0.02-0.08
0.03-0.10
0.03-0.09
0.02-0.08
0.02-0.08
0.01-0.03
0.02-0.09
0.03-0.10
0.02-0.07 		0.01-0.03
0.02-0.06
0.01-0.05
0.01-0.04
0.01-0.04
0.01-0.05
0.01-0.05
0.02-0.06
0.02-0.05
0.02-0.07
0.01-0.03
0.01-0.05
0.02-0.07
0.01-0.03
0.02-0.07
0.02-0.08
0.01-0.02
0.01-0.03
0.01-0.05
0.02-0.06
0.02-0.06
0.01-0.05
0.01-0.05
0.01-0.02
0.02-0.05
0.02-0.06
0.01-0.04 		0.01-0.03
0.01-0.05
0.01-0.04
0.01-0.03
0.01-0.03
0.01-0.04
0.01-0.04
0.01-0.04
0.01-0.04
0.02-0.06
0.01-0.02
0.01-0.04
0.01-0.06
0.01-0.03
0.01-0.05
0.02-0.07
0.01-0.02
0.01-0.02
0.01-0.04
0.01-0.05
0.01-0.05
0.01-0.04
0.01-0.04
0.00-0.01
0.01-0.04
0.01-0.05
0.01-0.04

Note: Values represent range of savings due to variations in rate of dusting and to uncertainties in effect of dust on heat flows. This level of degradation would be typical over 25 years of exposure.

Figures in table are based on a radiant barrier that had an emissivity of 0.05 or less when clean. Savings are for a 25 year period.

Table 4

Present Value Savings for Radiant Barrier Attached to Bottoms of Rafters

(Note: R-11, R-19, R-30, and R-38 refer to the existing level of conventional insulation.)

City Present Value Savings, Dollars per Square Foot of Attic Floor
R-11 R-19 R-30 R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		0.17-0.19
0.24-0.27
0.21-0.25
0.18-0.20
0.17-0.19
0.19-0.22
0.19-0.22
0.23-0.28
0.22-0.25
0.30-0.36
0.11-0.12
0.23-0.27
0.28-0.36
0.18-0.19
0.26-0.32
0.36-0.43
0.14-0.15
0.14-0.16
0.20-0.24
0.27-0.37
0.23-0.26
0.21-0.24
0.21-0.24
0.11-0.12
0.22-0.26
0.26-0.31
0.20-0.23 		0.08-0.09
0.12-0.15
0.10-0.13
0.09-0.10
0.08-0.10
0.10-0.12
0.10-0.12
0.12-0.15
0.11-0.13
0.15-0.19
0.06-0.07
0.11-0.14
0.15-0.20
0.08-0.10
0.13-0.17
0.17-0.23
0.06-0.06
0.07-0.08
0.10-0.12
0.13-0.17
0.12-0.14
0.10-0.12
0.10-0.13
0.05-0.05
0.11-0.13
0.13-0.17
0.09-0.12 		0.04-0.05
0.08-0.10
0.06-0.08
0.05-0.06
0.05-0.06
0.06-0.08
0.06-0.08
0.07-0.10
0.07-0.09
0.09-0.12
0.04-0.05
0.07-0.09
0.09-0.13
0.05-0.06
0.08-0.12
0.10-0.14
0.03-0.04
0.04-0.05
0.06-0.08
0.07-0.10
0.07-0.10
0.06-0.08
0.06-0.08
0.03-0.03
0.07-0.09
0.08-0.11
0.06-0.07		 0.03-0.04
0.06-0.08
0.05-0.07
0.04-0.05
0.04-0.05
0.05-0.07
0.05-0.07
0.05-0.08
0.05-0.07
0.07-0.10
0.03-0.04
0.06-0.08
0.07-0.10
0.03-0.04
0.07-0.10
0.08-0.12
0.03-0.03
0.03-0.04
0.05-0.07
0.06-0.08
0.06-0.08
0.05-0.07
0.05-0.07
0.02-0.02
0.05-0.07
0.06-0.09
0.05-0.06

Note: First value applies to houses with no air-conditioning ducts in attics. Second value appliesto houses with air-conditioning ducts in attics.

Figures in table are based on a radiant barrier with an emissivity of 0.05 or less, with the radiant barrier covering the insides of the gables. Savings are for a 25 year period.

Table 5

Present Value Savings for Radiant Barrier Draped over Tops of Rafters or Attached to Roof Deck

(Note: R-11, R-19, R-30, and R-38 refer to the existing level of conventional insulation.)

City Present Value Savings, Dollars per Square Foot of Attic Floor
R-11 R-19 R-30 R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		0.16-0.17
0.21-0.24
0.19-0.22
0.17-0.18
0.15-0.17
0.17-0.19
0.17-0.20
0.20-0.25
0.19-0.22
0.27-0.32
0.10-0.11
0.20-0.24
0.25-0.31
0.16-0.18
0.23-0.28
0.31-0.38
0.13-0.13
0.13-0.14
0.18-0.21
0.24-0.33
0.20-0.23
0.19-0.21
0.18-0.21
0.10-0.11
0.20-0.23
0.23-0.28
0.18-0.21 		0.07-0.08
0.11-0.14
0.09-0.12
0.08-0.09
0.07-0.09
0.09-0.10
0.09-0.10
0.10-0.14
0.10-0.12
0.14-0.17
0.06-0.06
0.10-0.13
0.13-0.18
0.07-0.09
0.11-0.15
0.15-0.20
0.06-0.06
0.06-0.07
0.09-0.11
0.11-0.15
0.10-0.13
0.09-0.11
0.09-0.11
0.04-0.05
0.10-0.12
0.11-0.15
0.08-0.10 		0.04-0.05
0.07-0.09
0.06-0.07
0.05-0.06
0.04-0.05
0.05-0.07
0.05-0.07
0.06-0.09
0.06-0.08
0.08-0.11
0.03-0.04
0.06-0.08
0.08-0.11
0.04-0.05
0.07-0.10
0.09-0.13
0.03-0.03
0.04-0.04
0.06-0.07
0.07-0.09
0.06-0.08
0.05-0.07
0.05-0.07
0.02-0.03
0.06-0.08
0.07-0.09
0.05-0.06 		0.03-0.04
0.06-0.07
0.04-0.06
0.03-0.04
0.03-0.04
0.05-0.06
0.05-0.06
0.05-0.07
0.05-0.07
0.06-0.09
0.03-0.04
0.05-0.07
0.06-0.09
0.03-0.04
0.06-0.09
0.07-0.11
0.02-0.03
0.03-0.04
0.04-0.06
0.05-0.07
0.06-0.07
0.04-0.06
0.04-0.06
0.02-0.02
0.05-0.06
0.05-0.08
0.04-0.05

Note: First value applies to houses with no air-conditioning ducts in attics. Second value applies to houses with air-conditioning ducts in attics.

Figures in table are based on a radiant barrier with an emissivity of 0.05 or less, with the radiant barrier covering the insides of the gables. Savings are for a 25 year period.

Table 6

Present Value Savings for Additional Insulation

City Present Value Savings, Dollars per Square Foot of Attic Floor
R-11 + R-8* R-11 + R-19 R-19 + R-11 R-19 + R-19
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C.		 0.76
0.53
0.50
0.90
0.69
0.64
0.33
0.31
0.53
0.47
0.22
0.52
0.22
0.80
0.25
0.53
0.73
0.50
0.50
0.49
0.44
0.65
0.63
0.52
0.61
0.41
0.60 		1.10
0.80
0.71
1.35
1.02
0.96
0.48
0.49
0.78
0.70
0.33
0.74
0.34
1.21
0.37
0.77
1.09
0.77
0.72
0.70
0.65
0.97
0.92
0.80
0.92
0.62
0.88 		0.35
0.28
0.21
0.45
0.33
0.32
0.15
0.18
0.24
0.23
0.11
0.22
0.11
0.42
0.12
0.24
0.37
0.27
0.22
0.21
0.22
0.32
0.29
0.28
0.31
0.21
0.28 		0.48
0.37
0.29
0.61
0.45
0.44
0.20
0.24
0.34
0.32
0.15
0.31
0.15
0.57
0.17
0.33
0.50
0.36
0.31
0.29
0.29
0.44
0.40
0.37
0.42
0.28
0.38

*Denotes existing level of conventional attic insulation (for example, R-11), and additional amount (for example, R-8). Savings are for a 25 year period.

Table A1

Average Reductions In Ceiling Heat Flow Due To Addition of Radiant Barrier to R-19 Attic Floor Insulation

SUMMER COOLING CONDITIONS

Radiant Barrier Location Whole House Tests Test Cell Tests
MIMA ORNL FSEC* TVA
Roof: attached to roof deck ---- ---- 36 - 42% 16%
Roof: draped over rafters 20%** ---- ---- ----
Roof: stapled between rafters ---- ---- 38 - 43% ----
Roof: stapled under rafters 24% 25 - 30% ---- 23 - 30%
Attic Floor*** 35% 32 - 35% 38 - 44% 40 -42%

*Tested at attic air space ventilation rate of five air changes per hour. Typical average ventilation rates are somewhat lower.

**Test was a simulation of draped configuration. The radiant barrier did not extend over the rafters, but was stapled near the joints between the rafters and the roof deck.

***Values are for new and undusted radiant barrier installations; percentages will be lower for aged radiant barriers.

Table A2

Average Reductions in Ceiling Heat Flow Due to Addition of Radiant Barrier to R-19 Insulation

WINTER HEATING CONDITIONS

Radiant Barrier Location Whole House Tests (ORNL) Test Cell Tests (TVA)
Roof: attached to roof deck ---- 4%
Roof: draped over rafters ---- ----
Roof: stapled between rafters ---- ----
Roof: stapled under rafters 5% to 8% 8%
Attic Floor 1% to 19% 15%

Notes for Tables A1 and A2:

Caution: These % values do not represent utility bill savings and cannot be represented as such.

NOTE: All measurements represent average heat flows through the insulation path, and do not include effects of heat flow through framing.

Key to Abbreviations:
FSEC: Florida Solar Energy Center
ORNL: Oak Ridge National Laboratory
MIMA: Mineral Insulation Manufacturers Association
TVA: Tennessee Valley Authority

Table X

Equipment Efficiencies

Low Medium High Very High
Gas Furnace (AFUE) 0.50 0.65 0.80 0.90
Oil Furnace (AFUE) 0.50 0.65 0.80 0.90
Heat Pump (COP)
Heating/Cooling		 1.6/2.1 1.9/2.6 2.2/3.1 2.5/3.4
Air Conditioner (COP) 1.8 2.3 2.9 3.5
Electric Furnace 1.0 1.0 1.0 1.0
Electric Baseboard Heating 1.0 1.0 1.0 1.0

Table Y1

Cooling Load Factors for Radiant Barriers

(Note: R-11, R-19, R-30, and R-38 refer to the existing level of conventional insulation.)

City R-11 R-19 R-30 R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		876
1598
1673
706
960
1020
1232
2162
1597
2535
429
1832
3090
769
2575
3308
297
551
1440
1999
1592
1286
1466
223
1523
2371
1221 		409
851
832
388
475
550
636
1120
823
1210
256
907
1631
418
1299
1595
120
299
738
931
849
651
757
119
790
1175
622 		259
522
516
245
284
357
405
672
517
703
168
555
938
257
832
942
82
178
460
556
542
409
479
80
512
713
386 		211
426
405
191
229
294
351
521
411
539
148
440
727
204
662
738
62
147
359
448
445
332
369
65
397
552
301

Figures in table are based on a radiant barrier with an emissivity of 0.05 or less when clean.

Table Y2

Heating Load Factors for Radiant Barriers

(Note: R-11, R-19, R-30, and R-38 refer to the existing level of conventional insulation.)

City R-11 R-19 R-30 R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		929
931
605
1192
842
989
792
387
725
774
738
630
99
1062
275
606
1112
937
741
892
821
906
738
904
868
477
912 		400
476
282
513
377
473
378
182
337
438
390
304
47
447
130
321
490
427
342
422
397
415
324
364
379
225
386 		193
299
163
293
210
277
242
108
206
277
227
180
28
223
77
191
253
238
219
248
236
223
169
197
219
138
212 		140
238
137
206
144
236
197
80
164
227
188
164
26
154
62
162
194
186
162
189
192
187
136
133
176
119
182

Figures in table are based on a radiant barrier with an emissivity of 0.05 or less when clean.

Table Y3

Cooling Load Factors for Additional Insulation (Note: R-11, R-19, R-30, and R-38 refer to the existing and addition levels of conventional insulation.)

City R-11 to R-19 R-19 to R-30 R-30 to R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		1171
1100
1649
695
1061
715
854
1310
1476
1960
214
1797
1694
471
1435
3175
392
368
1375
1983
1145
966
1482
169
991
1606
1210 		258
689
508
226
293
344
384
945
527
997
122
584
883
259
691
1334
66
316
434
713
582
462
444
73
465
819
392 		87
189
184
84
99
117
123
247
193
369
25
219
315
90
284
488
27
60
153
241
194
159
186
23
193
317
138

Table Y4

Heating Load Factors for Additional Insulation(Note: R-11, R-19, R-30, and R-38 refer to the existing and addition levels of conventional insulation.)

City R-11 to R-19 R-19 to R-30 R-30 to R-38
Albany, NY
Albuquerque, NM
Atlanta, GA
Bismarck, ND
Chicago, IL
Denver, CO
El Toro, CA
Houston, TX
Knoxville, TN
Las Vegas, NV
Los Angeles, CA
Memphis, TN
Miami, FL
Minneapolis, MN
Orlando, FL
Phoenix, AZ
Portland, ME
Portland, OR
Raleigh, NC
Riverside, CA
Sacramento, CA
Salt Lake City, UT
St. Louis, MO
Seattle, WA
Topeka, KS
Waco, TX
Washington, D.C. 		5358
3460
2660
7072
4923
4765
1977
1358
3145
2114
1706
2711
254
6399
712
1444
5870
3980
2977
2302
2651
4623
4010
4328
4297
1966
3999 		2751
1697
1332
3610
2569
2450
923
632
1584
1042
814
1359
121
3323
390
744
3096
1992
1489
1121
1294
2321
2038
2295
2199
968
2014 		1030
626
497
1369
952
872
336
242
599
375
295
489
38
1239
125
318
1137
738
606
406
467
858
759
831
802
353
731

Table Z

Discount Factors Adjusted for Average Fuel Price Escalation (Based on 7 percent discount rate and 25 year life.)

Census Region Electricity Fuel Oil Natural Gas
1
2
3
4

U. S. Average

11.68
11.37
11.50
12.12

11.56

15.33
15.56
15.33
15.58

15.41

13.85
14.42
14.36
4.46

14.33

Region 1: Maine, New Hampshire, Vermont, Massachusetts, Connecticut, Rhode Island, New York, New Jersey, Pennsylvania

Region 2: Ohio, Indiana, Illinois, Michigan, Wisconsin, Minnesota, Iowa, Missouri, North Dakota, South Dakota, Nebraska, Kansas

Region 3: Delaware, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida, Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, Oklahoma, Texas

Region 4: Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, Hawaii

Source: "Energy Prices and Discount Factors for Life-Cycle Cost Analysis 1988," NISTIR 85-3273-3, U. S. Department of Commerce, November 1988.

Worksheet

ENERGY SAVINGS ESTIMATE FOR RADIANT BARRIERS OR ATTIC INSULATION WORKSHEET

COST OF ENERGY FOR HEATING AND COOLING

Code: (A) (B) (C) (D) (E) (F)
Cooling Equipment Efficiency
(From Table X)		 Heating Equipment Efficiency
(From Table X)		 Cooling Fuel Price
$/Million BTU		 Heating Fuel Price
$/Million BTU		 Cooling Energy Cost
$/Million BTU
[C÷A]		 Heating Energy Cost
$/Million BTU
[D÷B]






For fuel prices:

Electricity: $/million BTU = ¢/KWH x 2.93
Natural Gas: $/million BTU = ($/therm or $/CCF) x 10
Fuel Oil: $/million BTU = $/gal. x 7.15

ESTIMATED ENERGY SAVINGS

Code: (1) (2) (3) (4) (5) (6) (7)
Ceiling Area, Square Feet Cooling Load Factor
(From Table Y)		 Heating Load Factor
(From Table Y)		 Annual Cooling Savings, $/yr
[(1) x (2) x E] ÷ 1,000,000		 Annual Heating Savings, $/yr
[(1) x (3) x F]÷ 1,000,000		 Total Energy Savings, $/yr
[(4)+(5)]		 Cost for RB or Insulation, $







ESTIMATED LIFE CYCLE PRESENT VALUE SAVINGS

Code: (8) (9) (10) (11) (12)
Cooling Discount Factor
(From Table Z)		 Heating Discount Factor
(From Table Z)		 Present Value Cooling Savings, $
[(4) x (8)]		 Present Value Heating Savings, $
[(5) x (9)]		 Total Present Value Energy Savings, $
[(10) + (11)]





Oak Ridge National Laboratory is managed by UT-Battelle for the Department of Energy