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Re: [EnergyPlus_Support] Lighting Control.



Hello again,

I have assigned stepped dimming control for the electric lights assigned to the building. Because of which the electric light power consumption follows the stepped control depending on the illuminance values. For the given ratio of 0.4 : 0.6 for the two reference points assigned in DAYLIGHTING: DETAILED and following the calculation that the electric lights consumption is given by =(Total Max power X The fraction assigned to the reference point X The fraction of power corresponding to the illuminance value) the calculations are fine for 6/21, but for 3/21 and 12/21 there are some mistakes (eg. on  3/21 values at 10am. and 5 pm. should be the same, and they do not match my hand calculations. Same thing for 12/21 at 10 am. and 5 p.m. for example.)  I am attaching the Idf file as well as the excel sheet in the files section . The name of the file would be 2008.06.17 LIGHTING CONTROL.

The values obtained vary  slightly from the expected output.
I would like to know if Energy Plus has any other Method of calculating the Electric power consumption from Lights ?

Thank you




----- Original Message ----
From: Rob Hitchcock <RJHitchcock@xxxxxxx>
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Sent: Friday, June 13, 2008 8:22:52 PM
Subject: Re: [EnergyPlus_Support] Lighting Control.

I have responded directly to you with several problems that I found in
your IDF. However, one of the problems is somewhat subtle and relevant
to others on this list who may be doing daylighting analysis, so I
repeat it here.

In the LIGHTS input object, Fraction Replaceable must be set to 1.0 in
order for electric light dimming due to daylight to take effect. This
is documented in the I/O reference (see comment below), and also a
warning is generated in the ERR file. However, this is not always
obvious to users.

/Field: Fraction Replaceable

This field defines the daylighting control for the LIGHTS object.

If DAYLIGHTING: DETAILED or DAYLIGHTING: DElight is specified for the
zone, this field is used as an on/off flag for dimming controls. If set
to 0.0, the LIGHTS are not dimmed by the daylighting controls. If set to
1.0, the LIGHTS are allowed to be dimmed by the daylighting controls.
/==========
Deepak Gv wrote:

>
>
> Hello Dr Hitchcock,
> Thanx for the prompt reply.I have made the changes to the reference
> points as you had suggested before. I have also run the file with the
> Electric lighting dimming control
> "continuous" (1), But I don't observe any changed in the Lighting
> Electric Power Consumption. I think it is not able connect the
> lighting consumption with the illuminance values at the two reference
> points.
>
> I am not able to figure out the exact problem. Is there any connection
> between lighting control and lighting electric consumption that I am
> not aware of ?
>
> Thank you again.
>
> ----- Original Message ----
> From: Rob Hitchcock <RJHitchcock@ lbl.gov <mailto:RJHitchcock %40lbl.gov> >
> To: EnergyPlus_Support@ yahoogroups. com
> <mailto:EnergyPlus_ Support%40yahoog roups.com>
> Sent: Friday, June 13, 2008 6:21:58 PM
> Subject: Re: [EnergyPlus_ Support] Lighting Control.
>
> You cannot send attachments through this email list.
>
> Have you checked the location of your daylighting reference points as I
> suggested after looking at your previous input file? They were
> positioned at the ceiling at the back of a deep and narrow zone where
> they would not receive any daylight from the window, causing no
> reduction in your electric lighting power.
>
> Also, you might want to change your electric lighting dimming control to
> "continuous" (1) for your initial runs.
>
> Rob
>
> Deepak Gv wrote:
>
> > Hello Everyone,
> >
> > I am involved in the simulation of Window blinds. I have been
> > performing some simulations for simple blinds system. I am having a
> > 6'X6' window on an 10' X 11' wall. From the output results that I am
> > getting, I am trying to obtain illuminance values at two reference
> > points. I have set the lighting control in DAYLIGHTING: DETAILED to 2.
> > According to the Input output reference manual the electric power
> > input and light output vary in discrete, equally spaced steps. I have
> > set then umber of steps to three. The illuminance setpoint at both the
> > reference points is set to 500 lux.
> >
> > After running the simulation I observe that the Electric lighting
> > output does not change with the increase in the illuminance value. It
> > remains at the constant value that it is set to according to the
> > Schedule.
> > I am attaching the Idf file named LIGHTING CONTROL-06.12 in the files
> > section. I would like to know the possible reason for these results.
> >
> > Thank you.
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
>

--

Robert J. Hitchcock, Ph.D.
Lawrence Berkeley National Laboratory
1 Cyclotron Road, Mailstop 90-3111
Berkeley, CA 94720

RJHitchcock@ lbl.gov
530.295.9433 (telecommute office)

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


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