2. Windows are a notorious path for heat flow into or out of a building. The current windows in this stricter have a U-factor of 0.81 Btu/hrft2F. Look up the U-factor for 3 commercially-available windows that are better than what is in there. Detail the cost assuming all windows in the building are 5' tall x 3' wide double hung. Add 10% to the cost for installation, and make a small table detailing the effect of the 3 window upgrades on UgAg, and on U.A.. As part of the table, include the savings in gas for the months of November-April each year, and the payback period in years. 3. Instead of replacing windows, a homeowner who happens to be a thermal sciences Professor comes up with the idea of simply installing exterior storm windows. Assuming each storm window costs $75, how does this impact UgAg, and on U.A,? Again, what is the savings in gas for the months of November-April each year, and the payback period for storm windows in years. 4. Instead of the current insulation, a homeowner who happens to be a thermal sciences Professor comes up with the idea of tearing out his drywall, removing the R-13 fiberglass insulation, putting in spacers over the studs so that instead of 3 inches the cavities are 4 inches, replacing it with rigid board extruded polystyrene insulation (XPS), and replacing the drywall. Calculate the effect of this upgrade on UwAw, and on UoAo. Look up the cost of the XPS and the drywall and calculate the payback period of this improvement. 5. Repeat #4, but in this case said Professor gets the XPS at a 50% discount and decides to thicker spacers so that he can put in 4 layers 2-inch thick XPS. Again, calculate the effect of this upgrade on UwAw, and on UoAo, including the payback period of this improvement. Are there any additional benefits to having XPS over the fiberglass insulation? 6. If someone were to buy R-13 fiberglass insulation to insulate the basement, what would be the cost and the payback for such an improvement? Would it be worth it to do? 7. From either problem #4 or #5, the Professor proposes to us the old fiberglass insulation ripped out of the walls to add an extra layer onto the attic. What would be the improvement in UaAa by adding an additional 3 inches onto existing attic insulation? 8. Reading through the attached RESNET document in Moodle on air infiltration, detail in a bullet- point list the improvements that can be made in the structure to decrease infiltration. Estimate percentage-wise the decrease in the infiltration rate, mcp (Btu/hrF). 9. If your goal as an owner of this building was to cut down the U.A. value by 50%, detail how you would go about doing it. Your solution can be any combination of the above, or other factors. You can copy the entire Excel page into multiple tabs going through various scenarios. Include cost and payback period in years. 10. Repeat # 9 above, but this time take U.A value down as low as you can. Include all detail and simple payback time in years. ENERGY USAGE HISTORY JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTAL JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TOTAL Usage in KWH 2011 2010 1322 848 1306 1090 1008. 800 2009 2008 2007 2006 2005 2004 Cost 1342 1236 1047 1300 1229 633 1 kW-hr 1335 1380 1085 1028 1343 1048 1185 1363 1119 $0.12 900 1073 1039 817 823 749 926 842 1026 904 799 801 997 807 808 769 732 720 1043 734 971 911 1014 671 873 2025 1244 546 1,397 1794 1705 972 2310 864 1394 666 648 2610 809 1238 1391 907 535 778 1583 1275 791 855 698 1,141 855 1258 995 879 952 774 737 1002 752 863 1136 1152 1224 1,026 1096 1083 1134 4436 13,884 12,538 11,846 11,833 12,415 14,929 11,009 Gas Usage in CCF* 263 2010 2009 2008 2007 2006 2005 388 344 137 335 393 329 388 236 367 260 350 275 283 330 331 298 338 266 119 201 190 128 76 97 34 68 40 24 30 22 28 26 24 34 5 20 35 26 44 102 71 33 123 79 197 150 244 178 185 265 1,383 1,587 1,808 1,783 1,410 1,657 1,862 2011 371 397 264 213 136 215 138 71 74 26 38 46 35 94 78 64 45 37 21 40 96 79 21 27 20 35 2004 Cost 1 CCF $1.02 *-all numbers present are for the month prior The UA, value for the structure, based upon usage data above, comes out to be 1,000 Btu/hr F. Based on that. Using the spreadsheet tool provided, and the one from homework #5, the goal is to decrease UoAo to save on energy cost. 1. Take the data from the "modified usage data" spreadsheet provided in homework # 5, and in addition to pulling out gas usage for water heating and dryer usage, make another take multiplying the remainder by a furnace efficiency of 80%. If you were to replace the 80% efficient furnace with a 95% efficient one, how much money would you save in the months of November-April each year? Looking up the cost of a 200,000 Btu 95% efficient furnace (document this), how many years would it take to pay back the investment?