A Problem regarding to Energy Plus to evelute the effect of PMV & PPD by verying the Air Velocity along with the effect of air

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Dear all,
I am doing an exercise on energy plus to simulate the effect of
Thermal comfort (PMV/PPD) and Energy consumption by varying the Air velocity
from .2 m/s to 2 m/s.

I have done some exercises to change the Air velocity from .2 m/s to 2
m/s and found that the effect on PMV/PPD. But the energy consuption
remains same at differene air velocity.
can anyone here help me find out the problems,

JAWAN RAWAT's picture
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Joined: 2011-10-02
Reputation: 0

Hi Jawan,

I think increasing the air velocity will surely show the effect on PMV/PDD,
but in energy-plus the air velocity is not not associated with the power of
equipment (it is only defined as a schedule with a particular value in m/s)
therefore it will not show any effect on the energy consumption.

Regards

|------------> | From: |
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|JAWAN RAWAT |
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|bldg-sim at lists.onebuilding.org |
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|09/29/2011 09:46 AM |
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|[Bldg-sim] A Problem regarding to Energy Plus to evelute the effect of PMV & PPD by verying the Air Velocity along with the effect of air velocity|
|on energy consumption of same zone. |
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Dear all,
? ? ? ? ? ?I am doing an exercise on energy plus to simulate the effect of
Thermal?comfort (PMV/PPD) and Energy consumption by varying the Air
velocity from .2 m/s to 2 m/s.

??I have done some exercises??to change the Air velocity from .2 m/s to 2
m/s and found that??the effect on??PMV/PPD. But the energy consuption
remains same at differene air velocity.
can anyone here help me find out the problems,

Deepak Tewari2's picture
Offline
Joined: 2011-10-02
Reputation: 0

As you know, there is no direct link between the comfort velocity and the air system flow rate but this can be accomplished in EnergyPlus using EMS. You would need to formulate your own model for the air velocity experienced by the occupants as a function of dynamic flow rate leaving the VAV air terminal unit. This model would depend on the distribution and nature of the supply air terminals. The general problem here is very complex and would probably require CFD to do accurately. But a simple engineering model could be developed for a specific zone by scaling from the air terminal flow rate (m3/s) divided by an appropriate zone hydraulic diameter or cross section (m2). This custom model would then be programmed in the EnergyPlus Runtime Language and included in the input file. You would set up a Sensor for flow rate leaving the air terminal and an Actuator on the schedule used for the air velocity in the People object. See the Application Guide for EMS.

Griffith, Brent2's picture
Joined: 2011-10-02
Reputation: 0