[EnergyPlus_Support] UFAD Vs MIXED + purchased air

["marziasedino" <marziasedino@xxxxxxxx>]

Hi all,

I am comparing a UFAD system with a traditional overhead one (MIXED) 
in order to assess difference in terms of energy performance and 
comfort for a tropical climate (no heating required).
As ouptut I would expect to see a higher value of "Purchased Air 
Sensible Cooling Energy" in the UFAD scenario to the MIXED one, but 
in my model this is not happening: sensible Cooling Energy is about 
the same in both cases even if the supply air temperature is 
considerably different.

My model is a middle floor within a tall building (adiabatic ceiling 
and floor) with about 70% WWR.
I simplified the two scenarios as follows:
1) UFAD: purchased air with UCSD UFAD INTERIOR MODEL CONTROLS,
T supply = 18 C
2)MIXED: purchased air without any roomair model (as it is mixed as 
default), T supply = 15 C.
Both scenarios include people, light and electric equipment heat 
gains.

Am I missing something? Do I need to use COMPACT HVAC to have a 
better evaluation?

Also,
I ran some sensitivity analysis on the "PurchAirTable" example file 
and I figured out that changing Tsupply of the Purchased Air the 
Sensible Energy Ouptut doesn't seem to vary, and so does not the 
total number of cooling/heating hours.
Is it right?

Thanks a lot for your help.
ciao

Marzia


------------------------------------

The primary EnergyPlus web site is found at:
http://www.energyplus.gov

The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/

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

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/join
    (Yahoo! ID required)

<*> To change settings via email:
    mailto:EnergyPlus_Support-digest@xxxxxxxxxxxxxxx 
    mailto:EnergyPlus_Support-fullfeatured@xxxxxxxxxxxxxxx

<*> To unsubscribe from this group, send an email to:
    EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/