Hi all! I have a problem with water coil sizing. I set the following parameters for cooling and heating:
Coil:Cooling:Water,
AHU%A%01 AHU Cooling Coil, ! - Component name
Cooling Coil, ! - Availability schedule
0.001700, ! - Design Water Volume Flow Rate of Coil (m3/s)
6.580000, ! - Design Air Flow Rate of Coil (m3/s)
18.00, ! - Design Inlet Water Temperature (C)
28.20, ! - Design Inlet Air Temperature (C)
24.00, ! - Design Outlet Air Temperature (C)
0.008, ! - Design Inlet Air Humidity Ratio
0.008, ! - Design Outlet Air Humidity Ratio
Coil:Heating:Water,
AHU_A_01 AHU Heating Coil 1, ! - Component name
Heating Coil, ! - Availability schedule
autosize, ! - U-factor times area value of coil (W/K)
autosize, ! - Max water flow rate of coil (m3/s)
AHU_A_01 AHU Heating Coil 1 Water Inlet Node, ! - Water inlet node name
AHU_A_01 AHU Heating Coil 1 Water Outlet Node, ! - Water outlet node name
AHU_A_01 AHU Steam Humidifier Air Outlet Node, ! - Air inlet node name
AHU_A_01 AHU Heating Coil 1 Air Outlet Node, ! - Air outlet node name
NominalCapacity, ! - Coil performance input method
59500.00, ! - Rated capacity (W)
45, ! - Rated inlet water temperature (C)
16.8, ! - Rated inlet air temperature (C)
40, ! - Rated outlet water temperature (C)
24, ! - Rated outlet air temperature (C)
0.50; ! - Rated ratio for air and water convection
But in the HTML I find this for Cooling:
AHU%A%01 AHU Cooling Coil: Nominal Total Capacity = 119722.30 [W]
And this for Heating:
AHU_A_01 AHU Heating Coil 1: Nominal Total Capacity = 138443.99 [W]
How is it possible? Where did I make the mistake?
Francesco Passerini
R2M Solution Srl16 thumbs up
March 7, 2018 - 12:23 pm
This question is related to the specific software.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 7, 2018 - 12:33 pm
Looks like EnergyPlus? You might have better luck here - https://energyplus.net/support
Giuseppina Amorusi
Artelia Italia2 thumbs up
March 8, 2018 - 4:33 am
Thank you Marcus.
The software we use is Design Builder. I put correct inputs in Design Builder: the same data reported in technical sheets for coils cooling and coils heating.
After annual simulation The Nominal Capacity reported in html outputs in Design Builder is a values greater than value entered in.
How it is possible?
I have investigated on web, but it seems that it is a problem of software. (We have also called Software house and they told us the same).
So I hope that with this explanation USGBC clarifications are ok.
But if you have any suggestions please let me know.
Thank you so much.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
March 8, 2018 - 9:50 am
Design Builder runs on the EnergyPlus engine.
I have no idea how this is possible. I would recommend that you ask the Energy Plus help desk.
The disparity on the heating capacity could potential be a red flag for the reviewer so I would recommend that you find out what is going on before submitting for LEED.