Is there a way to modify day schedules using global parameters. For example, say I want to compare the difference between having a setback start at 6 pm instead of 10 pm. I know how to create two different schedules and change them in the parametric run to get the difference.
However, let's say I want to use a single schedule to save time if I want to run many different parametric runs. In pseudo code, I would say something like-
Global parameter - Setback Hour (6 pm or 10 pm)
If time < "Setback Hour", then cooling setpoint is 72, else cooling setpoint is 80
There would be a similar code to bring the setpoint back to occupied.
Is it at all possible to create a User expression in the schedules that would to this? I could not find a keyword that corresponds to a time of day, so I think this all may be in vain.
Thanks,
Todd Lagus, EIT
Todd,
One way to do this is to set up a global parameter value for the hours
between 6 & 10 and change those parametrically. So you wouldn't be
varying the setback hour, but rather the temperatures at the time
between those hours. Not the cleanest way to do it, but it works.
Vikram Sami, LEED AP
Todd,
This may be more than you bargained for but here is some sample INP code
that will achieve what you're looking for:
**
$ ---------------------------------------------------------
$ Global Parameters
$ ---------------------------------------------------------
PARAMETER
"setback_hr" = 6 ..
$ ---------------------------------------------------------
$ Day Schedules
$ ---------------------------------------------------------
" Sample_Cool_SB" = DAY-SCHEDULE-PD
TYPE = TEMPERATURE
VALUES = (
{if(0> parameter("setback_hr")) then 72 else 80 endif},
{if(1> parameter("setback_hr")) then 72 else 80 endif},
{if(2> parameter("setback_hr")) then 72 else 80 endif},
{if(3> parameter("setback_hr")) then 72 else 80 endif},
{if(4> parameter("setback_hr")) then 72 else 80 endif},
{if(5> parameter("setback_hr")) then 72 else 80 endif},
{if(6> parameter("setback_hr")) then 72 else 80 endif},
{if(7> parameter("setback_hr")) then 72 else 80 endif},
{if(8> parameter("setback_hr")) then 72 else 80 endif},
{if(9> parameter("setback_hr")) then 72 else 80 endif},
{if(10> parameter("setback_hr")) then 72 else 80 endif},
{if(11> parameter("setback_hr")) then 72 else 80 endif},
{if(12> parameter("setback_hr")) then 72 else 80 endif},
{if(13> parameter("setback_hr")) then 72 else 80 endif},
{if(14> parameter("setback_hr")) then 72 else 80 endif},
{if(15> parameter("setback_hr")) then 72 else 80 endif},
{if(16> parameter("setback_hr")) then 72 else 80 endif},
{if(17> parameter("setback_hr")) then 72 else 80 endif},
{if(18> parameter("setback_hr")) then 72 else 80 endif},
{if(19> parameter("setback_hr")) then 72 else 80 endif},
{if(20> parameter("setback_hr")) then 72 else 80 endif},
{if(21> parameter("setback_hr")) then 72 else 80 endif},
{if(22> parameter("setback_hr")) then 72 else 80 endif},
{if(23> parameter("setback_hr")) then 72 else 80 endif} )
..
This allows the schedule "Sample_Cool_SB" to be linked to whatever week and
annual schedule and it sets the daily hours less than 6am to be 80F and the
daily hours greater than 6am to be 72F.
To add an ending condition (reset back to 80 at 8pm), you would need a
second parameter and a second if loop for each hour to achieve this.
*Note - if you don't feel like touching the *.inp file, manually add the
parameter and then add each if statement to the respective hours in the day
schedule you want to change.
Cheers,
Joel Travis, LEED AP
Does anyone know of a good way to model a system with coils that don't
have any control valves on them? It seems like the only two ways to
model a system are with either two-way or three-way valves on them.
Thanks.
Landon Streed