Thank you very much for your help and suggestion.
Best.
Tilak
On Thursday, November 26, 2015 4:51 PM, "Jean Marais jeannieboef@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Your friend is touching on an interesting point. If you are only concerned with annual energy usage and you have the relevant data for your kind of building and climate, you could lump ventilation and infiltration. This value is then an equivalent value that reflects the increase in annual energy consumption due to these two factors. It is a very valid approach. In fact, it is more accurate than guessing window opening and closing schedules and infiltration rates.
The hard way to model this is to model both infiltration and window ventilation explicitly. This becomes important for thermal comfort assessment. The first method does not capture discomfort, especially for short window opening events in winter and high CO2 levels.
If you are interested in the hard way, check the AirflowNetwork objects including occupant comfort driven window ventilation.
Good luck,
Jean
On 26 Nov 2015 1:00 pm, "Jim Dirkes jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Tilak,I think that you are correct: infiltration is unintended and uncontrolled. Ventilation is intended and controlled.Within EnergyPlus, infiltration can be specified as a constant value, but it can also be specified to vary with wind speed or occupancy. Inherently, the heating / cooling load from infiltration is a zone load.Ventilation, on the other hand, is delivered through an air loop and dependent on the air loop's function. Inherently, the heating / cooling load from ventilation is a system load.On Thu, Nov 26, 2015 at 4:08 AM, fati_tilak@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:Hi, Would you please help me to understand the different between ventilation and infiltration.in my case study, I want to model one residential zone which has some windows with an opening schedule for being open or closed. I think for simple modeling the effects of outdoor air flow , I should fill" Zone infiltration: design flow rate" or " Zone infiltration: Effective Leakage Area" and "Zone Ventilation: Design flow rate". Am I right?I am a little confused since one of my friend advised me to fill just "Zone infiltration: design flow rate" and increase the amount of ACH.As far as I understand Infiltration is for considering the effects of unintended flow and Ventilation is for considering the effects of purposeful flow from outside ( to provide non-mechanical cooling). So I think for considering the effects of purposeful windows opening , I should fill Ventilation object. But I am not sure.Thanks in advance for your time and great help.Tilak--James V Dirkes II, PE, BEMP, LEED AP
CEO/President
The Building Performance Team Inc.
1631 Acacia Dr, GR, Mi 49504
Direct: 616.450.8653
jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Website l LinkedInLove is the bridge over which Truth travels
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