[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[EnergyPlus_Support] Question: Radaint cooling slab and configuraion

Hi, All:
I have several questions for modelling a practical building.
The building is a seven-story university building. The building system has the following features:
1. VAV reheat system (Four primary air loops);
2. Radiant slab colling system for controlling part of the building(Including three loops, two loops serve the perimeter zones and one loop serves the core zone);
3. Radiant heating panel for heating in perimeter zones.
4. The heating and cooling source from university chilled and hot water net.
So could you help me with the following questions?
1. The radiant cooling slab supply water is the mixture of chilled water supply, return water from cooling coil and exit water from 
radiant slab. And the propotion of water mixture maybe is diffrent in three water loops. How can I set up this HVAC configuration? I mean the supply and demand side.
For my model right now. I just set up a chilled water loop for the cooling coils and three other chilled water loops for the three radiant cooling slab. All these use the PURCHASED COOLING. Is it an acceptable method?
2. For my model, I just run the simulation and get the result from the .bnd and HVAC schematic file. From these files, it shows the air loops configuration is correct. And there is no error report for the water supply and demand side braches (chilled water for the cooling coils and chilled water for the radiant slabs). But the .svg file (HVAC schematic file) cannot display until I delete all the supply and demand side braches for the radiant slab system ,even the file size is normal. 
The abnormal thing is that the reslut from the file without radiant slab system (Normal VAV system) is almost the same with the result from the file with radiant slab system. I checkd the source location temperature. In the same, the chilled water flow for the radaint slab is zero. But from the zone and system sizing, it shows the water flow. So is it possible that the 
branches is not linked correctly? 
What should be the correct zone equipment priority? I set the radaint system as the priority 1 and Air Unit as the last, and this is 
different from the example file. Is it correct?
 I just run the simulation on January 1 in a cold weather and it only takes few minutes but when I run it only on July 21, it takes more 
than 10 hours. I do not know what is up. If the radiant slab system does not work in Jan, it should be the same for the cooling coil. 

Thanks a lot for helping me out!
Best regards,
David Tian 

Do you Yahoo!?
Yahoo! Photos: High-quality 4x6 digital prints for 25¢

[Non-text portions of this message have been removed]

------------------------ Yahoo! Groups Sponsor ---------------------~-->
Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark
Printer at MyInks.com.  Free s/h on orders $50 or more to the US & Canada.

The primary EnergyPlus web site is found at:

The group web site is:

Attachments are not allowed -- please post any files to the appropriate folder in the Files area of the Support Web Site.
Yahoo! Groups Links

<*> To visit your group on the web, go to:

<*> To unsubscribe from this group, send an email to:

<*> Your use of Yahoo! Groups is subject to: