FIGURE I Heating Load Hours (HLH) for the United States and Territories This map is reasonably accurate for most parts of the United States but is necessarily highly generalized FIGURE 3 Average Outdoor Air Temperature vs. Balance Point Temperature for 50 50 TOA (Reduced input 45 40 35 30 30 25 TOA. BALANCE POINT TEMPERATURE TC (°F) This figure is based on 5200 degree-days and 5°F outdoor design temperature. FIGURE 4 Fraction of Total Annual Heating Load Applicable to Reduced Operating FRACTION OF TOTAL ANNUAL HEATING LOAD APPLICABLE TO REDUCED OPERATING MODE (X1) FRACTION OF TOTAL ANNUAL HEATING LOAD APPLICABLE TO MAXIMUM OPERATING MODE OR MODULATING MODE (X2) BALANCE POINT TEMPERATURE TC (°F) This figure is based on 5200 degree-days and 5°F outdoor design temperature. [49 FR 12159, Mar. 28, 1984, as amemded at 54 FR 6076, Feb. 7, 1989; 64 FR 11320, Mar. 17, 1989] |