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KWTON is the efficiency of the entire Chilled Water plant (DX Units).23.6937=5.5454 BTU/lb of dry air) -n. (29.2391ENTHALPHY is the difference in enthalpy of Mixed Air (76F db, 50%
<br /> RH) and Discharge Air (55F db, Saturated). 1240 ft elevatio HEATCOST is the rate of heating BTU. peak hours.-ELECCOST is the rate of electricity during offMeasured KW is the addition
<br /> of Supply Fan and Return Fan energy. 5 4 3 2 1
<br />
<br />EXHIBIT D
<br />FACILITY OPERATING PARAMETERS &
<br />UTILITY SAVINGS CALCULATION METHODS
<br />Library
<br />
<br />VFD - Control with VAV Boxes
<br />Elk River Library
<br />
<br />Energy Calculations - Variable Frequency Drives Optimization
<br />BASELINE PROPOSED SAVINGS
<br />HVACHRS
<br />
<br />Proposed Proposed Proposed Fan Energy Ventilation Cooling Fan Energy Ventilation Cooling Fan Energy Ventilation Cooling
<br />SUPPLY O.A. Measured Baseline Affected Proposed Baseline
<br />
<br />AHU # AREA SERVED CFM CFM KW Hrs/Wk Hrs/Wk Hrs/Wk % Flow S.F. CFM O.A. CFM % Flow kWh KWH kWh KWH kWh
<br />KWH KWH KWH KWH
<br />
<br />AHU-1 OA 2,055 0 4.66 75.50 76 60 70% 1,719 0 70% 6,279 0 0 4,990 0 0 1,289 0 0
<br />
<br />AHU-2 Library 12,905 1635 15.01 75.50 76 60 70% 10,797 1,635 70% 20,217 13,539 5,888 16,067 10,759 4,679 4,151 2,780 1,209
<br />
<br />AHU-3 Community Room 4,270 700 6.15 75.50 76 60 70% 4,270 700 70% 8,288 5,797 2,521 6,586 4,606 2,003 1,701 1,190 518
<br />
<br />TOTAL 34,783 19,336 8,409 27,643 15,366 6,683 7,141 3,970 1,726
<br />
<br />
<br />
<br />Assumptions
<br />
<br />VARIABLES CALCULATIONS
<br />See Table Above ...PRESENT HRS/WK OF SYSTEM OPERATION (HVACHRS) PROPOSED O.A. CFM
<br />0 ...HRS/WK OF SCHEDULED FOR WARMUP/COOLDOWN (WUCD) Fan Law #2: S.P.n/S.P.o = (CFMn/CFMo)^2
<br />52 ...WKS/YR OF AIR SYSTEM OPERATION (WPY) therfore: CFMn = CFMo * SQRT(S.P.n/S.P.o)
<br />See Table Above …Measured KW / Data Logger KW (FANKW) PROPOSED KW
<br />...ELECTRICITY UNIT ($) COST/KWHR (ELECCOST) Fan Law #3 BHPn/BHPo = (CFMn/CFMo)^3 (BHP is proportionate to KW); CFMn=CFMo * (S.P.n / S.P.o)
<br />4977 ...HEATING HRS/YR FROM WEATHER DATA (HHPY)
<br />therfore: (CFMn/CFMo)^3 = KWn/Kwo
<br />See Table Above ...TOTAL SUPPLY FAN CFM (CFM) FAN ENERGY (KWH/YR.)
<br />See Table Above …TOTAL OA CFM (OACFM) Basseline = (WINTER KW * HVACHRS * (HHPY/168)) + (SUMMER KW * HVACHRS * (52-(HHPY/168)))
<br />62 ...UNOCCUPIED HRS. SPACE HEATING SETPOINT (HTSPUNOC) Proposed = (PROPOSED WINTER KW * HVACHRS * (HHPY/168)) + (PROPOSED SUMMER KW * HVACHRS * (52-(HHPY/168)))
<br />27.9 ...AVERAGE O.A. TEMP. DURING HEATING SEASON (AVEDBT)
<br />FAN ENERGY COST ($/YR.)
<br />...$/BTU COST OF HEATING ENERGY (HEATCOST)
<br />= FAN ENERGY * ELECCOST
<br />0.9 …BOILER EFFICIENCY (BTU)
<br />VENTILATION (BTU/YR.)
<br />1.4 …CHILLER EFFICIENCY IN KW/TON (KWTON)
<br />Basseline = ((BIN-DELTA T-HRS) * OACFM * 1.08) + (0.4 * (BIN-DELTA T-HRS) * TOTAL-CFM * 1.08)
<br />2462 ...COOLING HRS/YR FROM WEATHER DATA (CHPY)
<br />Proposed = ((BIN-DELTA T-HRS) * PROPOSED OACFM * 1.08) + (0.4 * (BIN-DELTA T-HRS) * PROPOSED TOTAL-CFM * 1.08)
<br />14.7 ...COOLING WEEKS PER YEAR (CWPY) = (CHPY/168)
<br />VENTILATION COST ($/YR.)
<br />6.2 …COOLING ENTHALPY DELTA (ENTHALPY) 55
<br />= VENTILATION COST * HEATCOST
<br />…MIXED AIR TEMPERATURE SETPOINT (MAT)
<br />COOLING (KWH/YR.)
<br />
<br />Basseline = (HVACHRS * CWPY * OACFM * 4.5 * ENTHALPY / 12,000) * KWTON
<br />Proposed = (HVACHRS * CWPY * PROPOSED OACFM * 4.5 * ENTHALPY / 12,000) * KWTON
<br />COOLING COST ($/YR.)
<br />= COOLING COST * ELECCOST
<br />
<br />
<br />
<br />
<br />Public Safety
<br />
<br />BAS Start Stop
<br />
<br />
<br />Energy Calculations - Optimum and Schedule Start/Stop Strategy
<br />HVACHRS HRSOCC BASELINE PROPOSED SAVINGS
<br />
<br />SUPPLY O.A. Measured Baseline Proposed Savings Fan Energy Ventilation Cooling Fan Energy Ventilation Cooling Fan Energy Ventilation Cooling
<br />
<br />AHU # AREA SERVED
<br />CFM CFM KW Hrs/Wk Hrs/Wk Hrs/Wk KWH Therms KWH KWH Therms KWH KWH Therms KWH
<br />
<br />MAU-1 Offices 6000 6,000 2.98 80.5 70.0 11 12,491 6,587 31,550 10,862 5,728 27,434 1,629 859 4,115
<br />
<br />
<br />TOTAL 12491 6587 31550 10862 5728 27434 1629 859 4115
<br />Assumptions
<br />
<br />
<br />VARIABLES CALCULATIONS
<br />See Table Above ...PRESENT HRS/WK OF SYSTEM OPERATION (HVACHRS)
<br />FAN ENERGY (KWH/YR.)
<br />See Table Above ...HRS/WK OF ACTUAL BUILDING OCCUPANCY (HRSOCC)
<br />= FANKW * HVACHRS * WPY
<br />0 ...HRS/WK OF SCHEDULED FOR WARMUP/COOLDOWN (WUCD)
<br />
<br />52 ...WKS/YR OF AIR SYSTEM OPERATION (WPY)
<br />FAN ENERGY COST ($/YR.)
<br />See Table Above …Measured KW / Data Logger KW (FANKW)
<br />= FAN ENERGY * ELECCOST
<br />...ELECTRICITY UNIT ($) COST/KWHR (ELECCOST)
<br />
<br />4977 ...HEATING HRS/YR FROM WEATHER DATA (HHPY)
<br />VENTILATION (BTU/YR.)
<br />See Table Above ...TOTAL SUPPLY FAN CFM (CFM)
<br />= HVACHRS * (HHPY/168) * OACFM * 1.08 * (HTSPUNOC-AVEDBT)
<br />See Table Above …TOTAL OA CFM (OACFM)
<br />
<br />62 ...UNOCCUPIED HRS. SPACE HEATING SETPOINT (HTSPUNOC)
<br />VENTILATION COST ($/YR.)
<br />27.9 ...AVERAGE O.A. TEMP. DURING HEATING SEASON (AVEDBT)
<br />= VENTILATION COST * HEATCOST
<br />80% Heating Eff
<br />
<br />1.4 …CHILLER EFFICIENCY IN KW/TON (KWTON)
<br />COOLING (KWH/YR.)
<br />2462 ...COOLING HRS/YR FROM WEATHER DATA (CHPY)
<br />= (HVACHRS * CWPY * OACFM * 4.5 * ENTHALPY / 12,000) * KWTON
<br />14.65 ...COOLING WEEKS PER YEAR (CWPY) = (CHPY/168)
<br />
<br />8.49 …COOLING ENTHALPY DELTA (ENTHALPY)
<br />COOLING COST ($/YR.)
<br />
<br />= COOLING COST * ELECCOST
<br />
<br />EXHIBIT D Page 21 of 27
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