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[EnergyPlus_Support] Calculated load different from component sizing summery
Dear E+ users, I provided results to an engineering firm today and they asked a question I am not sure how to search for the answer to in the documentation or archives, and I am hopeful that someone might get me up to speed so I can answer his question-
First the math;
- Calculated Design Load= [Btu/h]3244.06
- Maximum Total Cooling Capacity=
[ton]0.416702 (
0.416702*12,000=[Btu/h]5000.424
- So what is the cooling system size recommended by this E+ run , as there is a difference of
[Btu/h]1756.364/[ton]0.1463636
His questions on the attached HTML results are:
- Design load is 3244btu/hr, system load is 5000 btu/hr (0.416 tons), why such a difference? It seems too much of a difference to be the ventilation load only
- Can you check the space sensible and latent load, the 4000 Btu/h cooling loads I have the system designed to is the total load (sensible + latent), therefore this may further explain the difference, I suspect energyplus is quoting only the sensible load under the calculated design load, this taps into the above question and the system load is likely both, but now this looks too high?
From my understanding latent+sensible is total load, but if that is the case then why would the component sizing be different than the HVAC sizing summery?
Many thanks for any thoughts--
| Calculated Design Load [Btu/h] | User Design Load [Btu/h] | Calculated Design Air Flow [ft3/min] | User Design Air Flow [ft3/min] |
Design Day Name | Date/Time Of Peak | Temperature at Peak [F] | Humidity Ratio at Peak [lbWater/lbAir] |
| BLOCK1:ZONE1 |
3244.06 | 4055.08 | 149.668 | 187.086 | LOS ANGELES INTL ARPT ANN CLG 1% CONDNS DB=>MWB | 8/21 16:35:00 |
79.27 | 0.00955 |
| Maximum Heating Air Flow Rate [ft3/min] | Maximum Cooling Air Flow Rate [ft3/min] | Maximum Total Cooling Capacity [ton] |
|
ZONE1AIR | 32.12 | 187.09 | 0.416702 |
Jeremiah D. Crossett | Senior Analyst | Phase Change Energy Solutions
120 E. Pritchard St. | Asheboro, NC 27203 | Mobile 503-688-8951
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