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

[EnergyPlus_Support] Zone Mechanical Ventilation reporting variables

Howdy all;

I'm trying to get an idea of the envelope load in one of my projects using a method outlined by Michael Witte in earlier posts in this group, ie:

envelope load =~ total load - internal loads - infiltration load - ventilation load - windows gains/losses

I'm having some trouble determining ventilation load, and I was thinking that the Zone Mechanical Ventilation reporting variables could possibly be of use. However, I've done some test runs and I'm having a hard time understanding them. 

For example, when the zone mean air temperature is about 16.5 C, the setpoint temperature is 15 C, and the ventilation air is getting delivered at 18 C, values appear in the "Zone Mechanical Ventilation No Load Heat Removal" column, which seems strange to me as the ventilation system, in this situation, is adding heat to the zone. (I'm also not sure how the magnitude of this number is calculated, as it's nowhere near the result of a simple q = m * c * deltaT calculation, with deltaT being the difference between the zone mean air and ventilation air temperatures). Similarly, when the zone mean air temperature is 17.5, the setpoint is 17, and the ventilation air is delivered at 18 C, values appear in the "Zone Mechanical Ventilation Heating Load Increase" column, which again seems strange, as the ventilation air seems like it would be decreasing the heating load.

Am I misunderstanding these variables? Or, alternatively: is there a better/different way to determine "ventilation load?" 

Thanks a lot,

Josh



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

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/