DOE2
- Hourly Return Air Absolute Humidity in grains/lbm-dry air
- Return Air Relative Humidity Scatter Plot
- 25 standard HVAC systems available
- Coil and equipment default characteristics can be adjusted
- Proven and accepted tool
- Combines hourly load analysis with simulation
- Requires conversion of weather data file format
Example DOE2 space relative humidity output (raw):
SS-N - Relative Humidity Scatter Plot
In this scatter plot, the ordinate, appearing in the left column, shows relative humidity bins. The abscissa, shown at the top, gives hours of the day. Entered in each cell of the plot is the number of hours during the RUN-PERIOD for which the relative humidity of the system return air was in the particular relative humidity bin for this particular hour of the day. Only hours for which the fans are on are counted in this plot. The column at the far right is the sum of the entries in each row. It shows the frequency of relative humidity values for the RUN-PERIOD. (Because the relative humidity counts are made only for hours when the fans are on, summing the totals column will not sum to the number of hours in the run.)
Note: If fans are on due to NIGHT-CYCLE-CTRL, the hours will not be counted in the plot.
REPORT- SS-N RELATIVE HUMIDITY SCATTER PLOT FOR PVAVS2 WEATHER FILE- CZ01RV2 WYEC2
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TOTAL HOURS AT RELATIVE HUMIDITY LEVEL AND TIME OF DAY
HOUR 1AM 2 3 4 5 6 7 8 9 10 11 12 1PM 2 3 4 5 6 7 8 9 10 11 12 TOTAL
--- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- -----
90-100 0 0 0 0 0 0 1 0 1 2 2 1 2 2 2 1 1 0 0 0 0 0 0 0 15
80-89 20 20 19 17 16 18 17 27 34 39 35 34 36 35 32 33 35 25 21 17 14 12 17 16 589
70-79 141 148 155 147 158 169 169 188 180 187 189 181 181 165 163 184 172 154 149 129 149 154 148 146 3906
60-69 152 147 132 143 136 124 127 107 112 111 121 137 132 145 153 129 134 153 154 165 148 141 137 145 3285
50-59 48 46 54 53 50 49 42 36 34 22 15 9 13 16 12 15 20 28 34 45 45 47 54 49 836
40-49 4 4 5 5 5 5 9 6 3 3 2 3 1 2 3 3 3 5 7 9 9 9 8 9 122
30-39 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 2 1 0 7
20-29 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
10-19 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0-09 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
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EXCEL BASED HOURLY SIMULATION
- Hourly Return Air Relative Humidity based on iterated hourly difference [Latent Load – Latent Capacity]
- Iterations: as space %rh rises ® coil latent capacity increases ® causes space %rh to decrease ¿
- Return Air Relative Humidity Histograms from standard Excel functions
- HVAC system is modeled using regression analysis of manufacturer’s published performance data
- Can begin as very simple with virtually unlimited flexibility by increasing complexity …including sorbtion
- Requires programming of hourly loads or use of an external hourly load analysis
- Hourly weather data is needed in spreadsheet column format as 8,760 rows