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NISTIR 88-3801-1 ZIP--The Zip-Code Insulation Program, Version 2.0 Economic Insulation Levels for New and Existing Houses by Three-Digit Zip Code Users' Guide and Reference Manual (Revised edition) Stephen R. Petersen National Institute of Standards and Technology Gaithersburg, Maryland 20899 Sponsored by U.S. Department of Energy Conservation and Renewable Resources Office of Buildings Energy Research Building Systems and Materials Division 1000 Independence Avenue, SW Washington, D.C. 20585 January 1991 Abstract ZIP 2.0 (the ZIP Code Insulation Program) is a computer program developed to support the DOE Insulation Fact Sheet by providing users with estimates of economic R-values for thermal insulation in new or existing single-family houses. The ZIP program currently calculates economic levels of insulation for attics, cathedral ceilings, exterior wood-frame and masonry walls, floors over unheated areas, slab floors, basement and crawlspace walls, ductwork in unconditioned spaces, and water heaters. Site-specific estimates can be made for any location in the United States by entering the first three digits of its ZIP Code. Climate parameters are contained in a file on the ZIP diskette and automatically retrieved when the program is run. The user must designate the type of heating and cooling equipment present in the house. Default energy and insulation price data are also retrieved from the ZIP diskette, but these can be overridden to correspond to local prices. A comprehensive report is displayed with the economic R-values, advisory material, and a list of the user's input assumptions. The program and supporting files are contained on a single 5-1/4 inch diskette for use with microcomputers having an MS-DOS operating system capability. ZIP is intended for use by homeowners, homebuilders, architects, utilities, insulation manufacturers and installers, university extension services, conservation advocacy groups, and government agencies at any level. ii Preface The ZIP computer program was developed to support the calculations and data base used to estimate the economic levels of insulation published in the U.S. Department of Energy's Insulation Fact Sheet (DOE/CE-0180, Technical Information Center, P.O. Box 62, Oak Ridge, TN 37830, 1987). Programmatic direction of this project and the DOE Insulation Fact Sheet has been provided by David McElroy of the Oak Ridge National Laboratory. Sections 1 through 6 of this user's guide are included in a flat (ASCII) file on the ZIP disk under the name ZIP.DOC. The appendices documenting the calculational algorithms in ZIP are available only in the complete report. iii Contents Page Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Calculation of Economic Levels of Insulation. . . . . . . . . . . . 2 3. Program Installation. . . . . . . . . . . . . . . . . . . . . . . . 3 4. Running ZIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1 House and heating/cooling system data. . . . . . . . . . . . 4 4.2 Energy Prices. . . . . . . . . . . . . . . . . . . . . . . . 5 4.3 Selecting insulation systems for analysis . . . . . . . . . 5 4.4 Water heater data. . . . . . . . . . . . . . . . . . . . . . 6 4.5 Existing houses only--Existing levels of insulation. . . . . 7 4.6 Insulation costs . . . . . . . . . . . . . . . . . . . . . . 7 4.7 Duct insulation. . . . . . . . . . . . . . . . . . . . . . . 9 5. ZIP Report Format . . . . . . . . . . . . . . . . . . . . . . . . . 9 6. Finishing Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 List of Screen Illustrations 1. Start-up display. . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Menu for selecting insulation systems of interest . . . . . . . . . 6 3. Selecting existing level of insulation in attic . . . . . . . . . . 7 4. Designating attic insulation costs for selected R-values. . . . . . 8 5. Selecting duct size to be insulated . . . . . . . . . . . . . . . . 9 6. Screen display of results of ZIP analysis (example) . . . . . . . . 11 7. Additional information displayed at the end of a ZIP analysis . . . 12 iv 1. INTRODUCTION ZIP, the Zip Code Insulation Program, determines economic levels of insulation for new and existing houses in any location in the United States, given the first three digits of its Zip code. Economic insulation levels are determined for attics, cathedral ceilings, exterior walls, floors over unheated areas, slab floors, basement and crawlspace walls, and ducts in unconditioned spaces. In addition, ZIP will determine if a water heater insulation jacket is a cost effective investment, based on information supplied by the user. The economic levels computed by ZIP reflect the type and approximate energy efficiency of the heating and cooling systems specified by the user, as well as local energy prices and current installed insulation costs. Local climate data for the three-digit Zip code are retrieved from the ZIP disk. Default energy and insulation price data are also retrieved from the ZIP disk, but it is recommended that users override these latter values with estimates of local energy and insulation prices if available. ZIP is a public domain computer program developed by the National Institute of Standards and Technology (NIST, formerly the National Bureau of Standards) under the sponsorship of the United States Department of Energy (DOE)*. As ZIP is in the public domain, it may be freely copied and distributed. However it is requested that attribution be given to the National Institute of Standards and Technology. ZIP and its supporting data files are provided on a single 5-1/4 inch floppy disk (360K DSDD format) for use with microcomputers having an MS-DOS operating system (typical IBM-PC/XT/AT and compatible systems). This condensed guide to the ZIP program is contained in file ZIP.DOC on the ZIP disk and can be printed directly from the disk. The original ZIP program was written to calculate economic levels of insulation reported by three-digit ZIP Code in the Department of Energy's "Insulation Fact Sheet" (DOE/CE-0180, January 1987). The "Insulation Fact Sheet" provides useful information related to the choice of insulation materials for particular applications and suggestions related to its proper installation. This 12 page publication can be obtained from the U.S. Department of Energy, Technical Information Center, P.O. Box 62, Oak Ridge, TN 37830. The ZIP program has now been expanded and enhanced for more general use, allowing users to obtain more detailed recommendations based on local climate and cost conditions. ZIP is intended for use by any government or private agency (such as a utility company) being asked to provide advice to consumers on economic levels of insulation for new or existing houses. ZIP can also be used by insulation manufacturers, insulation installers, and by homeowners (either on their own personal computer or at some central location such as a home show, utility office, or energy conference). Where local building codes require more insulation than suggested by ZIP, the building codes should take precedence. ------ * Neither NIST nor DOE assumes any liability resulting from the use of the information provided by the ZIP program or from any errors or omissions in the program. 1 2. CALCULATION OF ECONOMIC LEVELS OF INSULATION The economic levels of insulation calculated by ZIP are based on an incremental type of analysis. Successive levels of insulation in each part of the house are evaluated to determine how far it pays to keep adding insulation and when to stop. For example, in an attic an economic analysis is performed at R-0 (no insulation), R-11, R-19, R-22, R-30, R-38, and R-49. As long as the additional insulation needed to increase the total R-value from one level to the next is found to be cost effective, that increment will be included in the recommended insulation level for that application. If it is not cost effective, that increment will not be included. In general, the more severe the climate, the higher the cost of energy, the lower the heating and cooling system efficiencies, and the lower the cost of insulation, the more it pays to add insulation and the higher will be its economic level. Economic calculations in ZIP are based on a reduction in long-term heating and cooling costs. For new houses, a 30-year life is used in calculating the economic level of insulation. That is, the economic level of insulation calculated for a new house will be the level which has the lowest present-value insulation cost plus energy cost over a 30-year period. For existing houses, a 20-year life is used in the calculations. In performing these calculations, a seven percent annual rate of return, over and above general inflation, is used to discount future savings to present value. If inflation is currently five percent, this is approximately equivalent to requiring a minimum 12 percent rate of return on the investment over its life. That is, the last increment of insulation used in each application must earn at least this rate of return to be considered cost effective. Moreover, residential energy savings are not taxed. Thus, for homeowners this 12 percent rate of return is an after-tax rate, significantly higher than most tax-free investments available to homeowners. Note that the first increments of insulation typically return much higher dividends than the last increment. Thus the average rate of return on the entire investment tends to be considerably higher than the minimum acceptable level, especially if there is little insulation to start with. There are other benefits from installing economic levels of insulation in houses. These might include increased occupant comfort, reduced demand for scarce energy resources, reduced peak energy demand, reduced pollution, and even reductions in global warming. However, none of these additional benefits are included in the ZIP analysis of insulation savings. The annual energy savings computed in the ZIP analyses for each level of insulation are not displayed. These calculations are based on an analysis of uniform surface areas (typically one square foot) for each component in a typical house under average operating conditions over a typical weather year. They would not provide any meaningful estimate of savings for the user's own house since the area of each component is unknown. Usually an energy audit of the house to be insulated is needed to make a meaningful estimate of the total savings that can be expected. 2 3. PROGRAM INSTALLATION ZIP 2.0 can be installed on and run from a hard disk or run directly from a floppy disk. To install ZIP on a hard disk, make a subdirectory called ZIP and copy all the files on the ZIP disk to that subdirectory. (If the floppy is in drive A, type COPY A:*.* d:\ZIP , where d: is the drive location of subdirectory ZIP.) If you are going to run ZIP from a floppy drive, you should copy all the files on the original disk to a disk formatted on the drive you intend to run it from. Then run ZIP from the copy, saving the original as a backup. (Take care not to run the original (360 KB) disk in a high density (1.2 MB) disk drive; it will likely be destroyed during the disk write process.) In general, hard disk installation is preferred since ZIP will read and write the supporting data files much faster. The following files are contained on the original ZIP disk. All of these files (except the user's guide file, ZIP.DOC) are needed to run the program. ZIP2.EXE The executable version of ZIP. CLIMATE2.DAT A file of climate data, keyed to three-digit ZIP Codes. INSCOST2.NEW A file of default insulation prices for new houses. INSCOST2.RET A file of default insulation prices for existing houses. ZIPINFO.FIL On-line summary of ZIP program. ENPR90.ASC Gas, oil and LPG (propane) prices by state. ELEC90.ASC Electricity prices (winter and summer) by ZIP code. DOEENPR.NE \ DOEENPR.MW \ DOE projections of energy price escalation rates for the DOEENPR.SE / Four major regions of the U.S. DOEENPR.W / ZIP.DOC This user's guide. 4. RUNNING ZIP To start ZIP, insert the disk into the current disk drive and type 'ZIP2'. If ZIP is run from a hard disk, make the ZIP subdirectory the current directory and type 'ZIP2'. If you have a color monitor, ZIP will automatically detect this and run in color. If you have a monochrome monitor that runs in the color mode, adding "/M" to "ZIP2" may make it easier to read the highlighted characters on the menus (e.g., start by typing ZIP2 /M). Screen 1 shows the initial screen display when ZIP is started. The user can proceed immediately into a ZIP analysis by pressing <Enter>. Further start-up options are provided in the menu bar at the bottom of the ZIP logo. For example, more information on the ZIP program can be displayed, or default input data from a previous run can be retrieved by selecting "Get File" and then selecting a previously saved input data file from the list shown on the screen. (You will be able to save your input data at the end of the ZIP run for later retrieval.) When you retrieve a file, the data in this file serve as the default data for the current run; you can edit this data if desired as you proceed through the data input process. 3 Screen 1. Start-up display ┌────────────────────────────────────────────────────────────────────────────┐ │ │ │ ╔═══════════════════════════════════════════════════════╗ │ │ ║ ▄▄▄▄▄▄▄▄▄▄▄▄ ▄▄▄▄ ▄▄▄▄▄▄▄▄▄ ║ │ │ ║ ▄▄ ▄▄ ▄▄ ▄ ║ │ │ ║ ▄▄ ▄▄ ▄▄ ▄ ║ │ │ ║ ▄▄ ▄▄ ▄▄▄▄▄▄▄▄▄ ║ │ │ ║ ▄▄ ▄▄ ▄▄ ║ │ │ ║ ▄▄ ▄▄ ▄▄ ║ │ │ ║ ▄▄ ▄▄ ▄▄ ║ │ │ ║ ▄▄▄▄▄▄▄▄▄▄▄▄ ▄▄▄▄ ▄▄ ║ │ │ ║ ║ │ │ ║ ──────────────────────────────────────────────── ║ │ │ ║ The Zip-Code Insulation Program, Version 2.0 (1990) ║ │ │ ╚═══════════════════════════════════════════════════════╝ │ │ ╔═══════════════════════════════════════════════════════╗ │ │ ║ Proceed More Info Get File Quit ║ │ │ ╚═══════════════════════════════════════════════════════╝ │ │ Use cursor to highlight choice and press <Enter> │ │ │ │ From the National Institute of Standards and Technology │ │ Sponsored by the U.S. Department of Energy │ │ │ └────────────────────────────────────────────────────────────────────────────┘ When you proceed with the ZIP analysis, the first entry is the postal Zip code for the location of interest. Enter the first three digits of the Zip code and ZIP will respond with the reference location and the corresponding heating degree days (base 65F) and cooling degree hours (base 74F). The reference location is typically the location designated by the U.S. Postal Service as the main post office at the three-digit Zip code level. If the location is acceptable, press <Enter>; otherwise select "Try another Zip Code" and enter another Zip Code as requested. 4.1 House and heating/cooling system data ZIP asks the user to designate whether the analysis is for a new or existing house, the type and approximate efficiency of the heating and cooling systems, and the presence of ductwork in unconditioned spaces. If there is ductwork in unconditioned spaces, ZIP will ask if the house has two or more stories. Note that a default response is always available, and that if the ZIP analysis is repeated, the user's last response for each question will become the default value for the current run. If a new house application is selected, a wider range of insulation options for exterior walls and exterior foundations is allowed than for existing houses. If an existing house analysis is selected, you will be asked to specify the approximate existing level of insulation in the attic, floor, crawlspace walls, and supply ducts after these systems are selected for analysis. 4 Six different heating systems can be selected in ZIP: four furnace types, including natural gas, fuel oil, LPG, and electric resistance; electric baseboard; and electric heat pump. If a heat pump is designated for space heating, it will automatically be assumed to provide space cooling as well, and no cooling questions will be asked. Otherwise, two electric cooling systems can be selected: central and window air conditioners. (An evaporative cooling system can also be selected. However, no cooling savings from insulation are calculated for this latter system.) In addition, the user can specify the approximate operating efficiency of the heating and cooling systems (low, medium, high, or very high). These system specifications are needed to calculate the purchased energy savings corresponding to any given reduction in space heating and cooling loads. If there is ductwork in attics, crawlspaces, or other unconditioned spaces, an adjustment is also made to the equipment efficiency to reflect duct losses (10 percent for one-story houses, 15 percent for houses with two or more stories). 4.2 Energy Prices Current energy prices for heating and cooling, corresponding to the type of systems selected, are then requested in the units shown (e.g., kWh, therms, gallons). Default values are retrieved from data files on the disk. These default values reflect energy prices at the state level (or, in the case of electricity, at a representative location within the state, based on the ZIP code entered for the analysis). However, it is recommended that the user overwrite these default values with energy prices that reflect the utility rates actually encountered at the building site. These prices should include all taxes and fuel adjustment costs (but not kW demand charges, if any). If declining (or increasing) block rates are applicable (for example, kWh prices are often lower for kWh usage above 500 kWh per month than for the first 500 kWh), the energy cost should reflect the cost of the last units purchased each month (during the months of major usage), not the average cost for all units. If there are different prices for summer and winter usage (as is often the case for electricity), the price used for cooling should be based on the summer rate and the price for heating on the winter rate. To change the default prices on the screen, press "Y" (Yes), then type the new prices over the old prices. 4.3 Selecting insulation systems for analysis Screen 2 shows the menu for selecting the insulation applications of interest to the user. Press <F3> to select all systems or use the cursor keys to move from box to box; press the space bar to toggle the selection marker (X) on or off in each box. Only data pertinent to the applications marked with an X will be requested and displayed after this point. Note that for some applications (e.g., cathedral ceilings and crawlspace walls) the analysis of rigid foam sheathing can be separately specified from mineral wool batts or blankets (or loose fill insulation materials of any kind). This is primarily because typical R-values for rigid foam sheathing differ significantly from those of batts/blankets/loose fill insulation materials. 5Since rigid foam sheathing typically costs more than mineral wool/loose fill for a given application, its economic R-value will be lower. However, for some applications rigid foam sheathing may be more suitable. Expert consultation may be needed to determine the appropriate material in specific circumstances. In the case of new wood-frame wall construction, a combination of mineral wool insulation and rigid foam sheathing is assumed for R-values above R-13. 4.4 Water heater data If water heater insulation is checked, four questions are asked about the water heater: its type, its capacity (in gallons), its expected remaining life, and the price of the heating fuel. Six types of water heaters are displayed for selection: gas, oil, and electric, with either mineral wool or foam tank insulation. If the water heating fuel is the same as the space heating fuel, the default unit price will be the same as entered for space heating. If electric water heating is used, the user will be asked to enter both the winter electricity rate and the summer electricity rate. The actual electricity rate used in the analysis will be based on two-thirds (eight months) of the winter rate plus one-third (four months) of the summer rate. The economic analysis of a water heater insulating jacket is limited to the owner's expectation of the water heater's remaining life, with no salvage value credited. The water heater is assumed to be located inside the house. However, potential beneficial heat gain from the tank during heating hours and undesirable heat gain during cooling hours is not considered in the analysis. Screen 2. Menu for selecting insulation systems of interest ┌────────────────────────────────────────────────────────────────────────────┐ │ Select Insulation Systems for Analysis │ │ Press <Space Bar> to Toggle System On [X] or Off [ ]. │ │ F3 = mark all. Use cursor keys to move around screen. │ │╔══════════════════════════════════════════════════════════════════════════╗│ │║ ATTIC: CRAWLSPACE WALLS: ║│ │║ [ ] 1. batt/blanket/loose fill [ ] 1. batt/blanket/loose fill ║│ │║ CATHEDRAL CEILINGS: [ ] 2. rigid foam sheathing ║│ │║ [ ] 1. batt/blanket/loose fill BASEMENT WALLS (HEATED SPACES): ║│ │║ [ ] 2. rigid foam sheathing [ ] 1. Exterior Insul. (rigid foam) ║│ │║ EXTERIOR WALLS (ABOVE GRADE): 2. Interior Insulation: ║│ │║ [ ] 1. Wood Frame (batt/blanket) [ ] a. batt/blanket ║│ │║ 2. Concrete-Masonry: [ ] b. rigid foam sheathing ║│ │║ [ ] a. batt/blanket/loose fill BASEMENT WALLS (UNHEATED SPACES): ║│ │║ [ ] b. rigid foam sheathing [ ] 1. Exterior Insul. (batt/blkt) ║│ │║ FLOORS: 2. Interior Insulation: ║│ │║ [ ] 1. Over unheated spaces (batt) [ ] a. batt/blanket ║│ │║ [ ] 2. Concrete slab (rigid foam) [ ] b. rigid foam sheathing ║│ │║ [ ] DUCT INSULATION [ ] WATER HEATER INSULATION ║│ │╚══════════════════════════════════════════════════════════════════════════╝│ │ Press <PgDn> when finished. │ │ │ └────────────────────────────────────────────────────────────────────────────┘ 6 4.5 Existing houses only--existing levels of insulation If the ZIP analysis is being performed for an existing house, the user is asked to specify the approximate existing level of insulation in the attic, floors over unheated spaces, crawlspace walls, and supply heating ducts if these systems have been selected for analysis. These selections are made from a menu displaying several R-values and the approximate equivalent thickness of insulation in inches. An example of this selection menu is shown in Screen 3 for attic insulation. In most other applications in existing houses (e.g., exterior walls), ZIP asks if there is any existing insulation in the component. If the user indicates that some insulation already exists in such components, ZIP advises that further insulation is generally impractical, since the cost of removing or penetrating wall coverings is often prohibitively costly and the potential savings is significantly reduced. 4.6 Insulation Costs Default insulation costs for each application checked are displayed. For most applications, three to eight different insulation levels are shown along with default estimates of their installed cost. An example of this insulation cost menu is shown in Screen 4 for attic insulation. ZIP will evaluate each of these levels to determine which is the most cost effective in this analysis, using the costs shown. The user can accept these default values; however it is recommended that the user enter values specific to the building site. Screen 3. Selecting existing level of insulation in attic ┌────────────────────────────────────────────────────────────────────────────┐ │ Attic Insulation - Batt/Blanket/Loose Fill │ │ How much insulation is there in your attic now? │ │ ╔═════════════════════════════════════════════════════╗ │ │ ║ Approximate Equivalent in Inches ║ │ │ ║ Existing -------------------------------- ║ │ │ ║ Insulation Fiberglass Cellulosic ║ │ │ ║ Level -------------------- Blown ║ │ │ ║ ------------- Batt Blown ---------- ║ │ │ ║ (0) None 0 ║ │ │ ║ (1) R-7 2.5 2.0 -3.0 2.0-3.0 ║ │ │ ║ (2) R-11 3.5 3.75-5.0 3.0-3.5 ║ │ │ ║ (3) R-19 6.0 6.5 -8.75 5.0-6.0 ║ │ │ ║ (4) R-22 7.0 7.5 -10.0 6.0-7.0 ║ │ │ ║ (5) R-30 9.0 10.25-13.75 8.0-9.5 ║ │ │ ║ (6) R-38 12.0 13.75-18.25 10.3-12.0 ║ │ │ ╚═════════════════════════════════════════════════════╝ │ └────────────────────────────────────────────────────────────────────────────┘ 7 Screen 4. Designating attic insulation costs for selected R-values ┌───────────────────────────────────────────────────────────────────────────┐ │ Attic Insulation Costs (Batt/Blanket/Loose Fill): │ │ (cost per square foot of gross attic area) │ │ ╔═════════════════════════════════════════╗ │ │ ║ R-11 @ $ 0.34 per square foot ║ │ │ ║ R-19 @ $ 0.47 per square foot ║ │ │ ║ R-22 @ $ 0.54 per square foot ║ │ │ ║ R-30 @ $ 0.67 per square foot ║ │ │ ║ R-38 @ $ 0.85 per square foot ║ │ │ ║ R-49 @ $ 1.05 per square foot ║ │ │ ╚═════════════════════════════════════════╝ │ │ │ └───────────────────────────────────────────────────────────────────────────┘ The default insulation costs include contractor installation, except for the water heater jacket, which is assumed to be installed by the homeowner. For do-it-yourselfers, these costs can be modified to reflect materials only or include the labor cost, as desired. In general, the higher the insulation cost, the lower will be the economic level of insulation, and vice versa. Before the insulation costs are requested, ZIP will display guidelines related to appropriate selection and entry of cost data. These guidelines are as follows: o All costs are to be entered in terms of thermal resistance (R) value, not thickness. o All costs are to be entered per square foot or per linear foot for the indicated R-value (as specified). If your cost estimates are for the total job, you must convert them to dollars per square foot or per linear foot of the insulated area (as indicated). o Insulation costs should include both material and labor costs if professionally installed. o If you are doing the job yourself, you can omit labor costs, or include the cost of your time, as you prefer. Economic insulation levels will generally be higher if labor costs are not included. o All insulation costs should include the cost of structural modifications or coverings if these additional costs cannot be justified for other purposes. o Each R-value for any given application is expected to cost more than the previous R-value, never the same or less. o Technically speaking, the difference in cost for each additional increment of insulation relative to the previous increment (e.g., R-19 relative to R-11) is more important than the total cost of that increment. Therefore, take care to make the cost differentials reasonable. 8 Entering a price of $99.99 for any level of insulation will eliminate that level from the economic analysis. (This is useful if a particular level is unavailable or inappropriate for the application of interest.) Note: the cost of each successive level of insulation must be higher than the previous level, unless $99.99 has been entered for the previous level. 4.7 Duct insulation If insulation on supply and return ducts in unconditioned spaces is to be analyzed, the approximate cross-section dimensions must be identified for the most representative sizes. The approximate size for each is selected from a menu of choices, as shown in Screen 5. Insulation costs for ducts are stated in dollars per linear foot of duct. Insulation costs per linear foot are typically higher for larger perimeter ducts than for ducts with small perimeters. Moreover, these costs tend to increase faster with increases in R- value than for other applications. This is because the outside perimeter (and thus the amount of insulation needed to wrap around it) increases with each new level. Both of these factors should be considered when specifying duct insulation costs. If supply ducts are used for air conditioning, the duct insulation should include a vapor barrier on the outside, sealed to prevent moisture from condensing on the ducts and wetting the insulation. Economic insulation levels are computed and reported separately for supply and return ducts in attics, vented crawlspaces, and controlled-ventilation crawlspaces. Screen 5. Selecting duct size to be insulated ┌─────────────────────────────────────────────────────────────────────────┐ │ SUPPLY DUCTS in unconditioned spaces: │ │ What is most typical duct size (approximate size in inches)? │ │ ╔═════════════════════════════════╗ │ │ ║ Round Rectangular ║ │ │ ║ ------- ------------- ║ │ │ ║ (A) 4 (F) 3 x 12 ║ │ │ ║ (B) 6 (G) 6 x 12 ║ │ │ ║ (C) 8 (H) 8 x 14 ║ │ │ ║ (D) 10 (I) 10 x 16 ║ │ │ ║ (E) 12 (J) 12 x 20 ║ │ │ ╚═════════════════════════════════╝ │ │ │ └─────────────────────────────────────────────────────────────────────────┘ 9 5. ZIP REPORT FORMAT The results of the economic analysis for the designated location are displayed directly on the screen as shown in Screen 6. The Zip code and reference location, number of annual heating degree days (base 65F) and cooling degree hours over 74F are shown. Also included at the top of the report are the types of heating and cooling equipment, seasonal energy efficiencies, and the fuel prices used in the analysis. If the ZIP analysis is for a new house, the economic level of insulation is shown for each application. For existing houses, the existing level, amount to be added, and total level for each application are shown. Note that the economic levels of insulation for both floors over crawlspaces and for crawlspace walls are shown if both were selected for analysis. However, only one of these methods would be used in most houses. For crawlspaces that can be safely closed off, it is usually more economical to insulate the walls than the floor above if the wall area is less than the floor area. If the crawlspace cannot be safely closed off (or it is not allowed by the local building code authority), the floor above should be insulated instead. In this latter case, care must be taken to insulate water pipes and any ductwork in the unheated area. Screen 7 shows the additional information displayed at the end of a full ZIP analysis. This information is provided to help the user better interpret and utilize the results of the ZIP analysis. However, it is recommended that the user read the DOE Insulation Fact Sheet or other insulation guidelines, or consult an insulation expert, before selecting the type of insulation to be used and installing it. 6. FINISHING UP While the ZIP output report is displayed on the screen, the following options are available by pressing the designated key, as indicated in the menu bar at the bottom of the screen: P The entire report displayed on the screen is sent to the printer. This report includes the economic levels of insulation for the applications considered in this analysis and the input data specified by the user, including the insulation prices used in the analysis. (Make sure that the printer is turned on and that the paper is properly positioned before selecting this option.) S Start over with another ZIP analysis, using the data input for the previous run as the default choices at every question in the new run. R Save this report as a flat file on your disk, for later retrieval by a word processor. I Save your input data to the disk for retrieval in a later ZIP analysis. You will be asked to enter a file name for this datafile. Use any valid DOS filename (eight character maximum). Do not enter a filename extension; the extension ".ZIP" is automatically tagged to the filename you enter. 10 Q Quit and return to DOS. You cannot back up after the ZIP report is displayed. You must press S and move through the data input screens again. However, you do not need to reenter your data since they are now the default responses to every question. Screen 6. Screen display of results of ZIP analysis (example) ┌────────────────────────────────────────────────────────────────────────────┐ │ Economic Insulation Levels for Zip 111XX -- New House │ │ Reference Location: Queens, NY │ │ Heating Degree Days(65F)=approx. 5000 Cooling Degree Hrs(74F)=approx. 9000│ │╔══════════════════════════════════════════════════════════════════════════╗│ │║ Heating Equipment: Natural Gas Cooling Equipment: Central- Electric ║│ │║ Seasonal Efficiency: 65% SEER (seasonal eff.): 8.0 Btu/Wh ║│ │║ Unit Fuel Cost: $0.650/therm Unit Fuel Cost: $0.140/kWh ║│ │╚══════════════════════════════════════════════════════════════════════════╝│ │ │ │ Attic Insulation R-38 │ │ Cathedral Ceiling Insulation │ │ Batt/Blanket R-30 │ │ Rigid Foam R-16 │ │ Wood-Frame Wall Insulation R-23 │ │ Masonry Wall Insulation │ │ Batt/Blanket R-19 │ │ Rigid Foam R-12 │ │ Floors over Crawlspace (If crawlspace walls uninsulated) │ │ Batt/Blanket R-19 │ │ Crawlspace Wall Insulation (If floor above is uninsulated) │ │ Batt/Blanket R-11 │ │ Crawlspace Wall Insulation (If floor above is uninsulated) │ │ Rigid Foam R- 5 │ │ Slab-Edge Insulation (Rigid Foam) R- 5 │ │ Insulation of Basement Walls: │ │ Exterior Insul. for Heated Basement (RF) R-10 │ │ Interior Insul. for Heated Basement │ │ Batt/Blanket R-19 │ │ Rigid Foam R-12 │ │ Exterior Insul. for Unheated Basement(RF) R- 0 │ │ Interior Insul. for Unheated Basement │ │ Batt/Blanket R- 3 │ │ Rigid Foam R- 6 │ │ Insulation of Supply Ducts in Unconditioned Spaces: │ │ Ducts in Attics: R- 8 │ │ Ducts in Vented Crawlspaces: R- 8 │ │ Ducts in Unvented Crawlspaces: R- 6 │ │ Insulation of Return Ducts in Unconditioned Spaces: │ │ Ducts in Attics: R- 6 │ │ Ducts in Vented Crawlspaces: R- 4 │ │ Ducts in Unvented Crawlspaces: R- 4 │ │ Water Heater Insulation Yes │ │ │ └────────────────────────────────────────────────────────────────────────────┘ 11 Screen 7. Additional information displayed at the end of a ZIP analysis ┌────────────────────────────────────────────────────────────────────────────┐ │ Additional information: │ │ │ │ Always specify insulation by R-value, not by thickness. If loose-fill │ │ materials are used, make sure that they are installed according to weight │ │ (e.g., pounds per square foot) or bag count and not simply to a target │ │ depth, as significant settling may occur after installation is completed. │ │ │ │ ALL insulation products should be kept away from unprotected heat sources. │ │ │ │ Insulate the floor over the crawlspace or the crawlspace walls, not both. │ │ Crawlspace walls should only be insulated if the crawlspace is closed off, │ │ unventilated, and dry all year. The ground should be covered with a vapor │ │ barrier (e.g., 4- or 6-mil polyethylene sheeting) to minimize moisture │ │ migration into the crawlspace. Note: some building codes may not allow │ │ unventilated crawlspaces. If radon gas is a problem at the building site, │ │ closing off the crawlspace may not be advisable. │ │ │ │ If insulating floors over crawlspaces or other unheated areas, make sure │ │ that exposed water pipes are freeze-protected and ductwork is properly │ │ insulated in those areas. │ │ │ │ Before insulating ducts, loosen any existing insulation at all joints and │ │ tape all joints to minimize air leakage. A non-flammable vapor barrier │ │ should cover the insulation on any supply ducts used for air conditioning. │ │ │ │ The water heater jacket should not cover combustion air inlets (if any), │ │ pipes, controls, relief valves, or the flue at the top of the heater. │ └────────────────────────────────────────────────────────────────────────────┘ 12