FILTER RESULTS FOR OCCUPIED HOURS ONLY

[iainsavage]

Is there a way of filtering results to only analyse occupied periods (number of people is greater than zero) e.g. by using custom variables, formulae etc? Btw I am aware of the ability to do this in the range test, but this only gives total hours above/below etc, I'm looking for more functionality such as peak temperature or minimum macroflo ventilation rate during only the occupied periods. Tried using the "IF" function but just kept getting syntax errors and finally gave up.

[bbrannon4]

Depending on your end goals and the specific variables you are looking at, you could use the sign() function, combined with some other math to make sure it always returns a positive number, on the occupant number which would give you either a 0 or a 1, which could be multiplied by the variable of interest. But if zero's are important to you and you want to get N/A's or something when unoccupied, I would have done the same thing as you with if statements. Something like: if (occupancy>0,variable_of_interest,NAN). I'm not sure why that wouldn't work. Maybe post some of your attempts and we might be able to troubleshoot your syntax errors.

[Complex Potential]

I normally just export all 8760 hours to Excel and include the people sensible gain variable as a column. It's then an easy task to create a new column which filters out the unwanted bits:

If temperature is in column C and people gain in column D then the filter cell in the first row would look like this (the filter column could be E for example):

=if(D1>0,C1,"")

You can then do a min or max function on the resulting column.

CP

[iainsavage]

In reply to Complex Potential, I had already tried to do some additional editing in Excel but I'm no expert on this. We have to do room-by-room analysis for a secondary school - can your method be easily adapted to filter results in this way for each room?

In response to Bbrannon4, the variables we are trying to analyse are (independantly, NOT coincidentally) maximum dry resultant temperature and minimum macroflo external ventilation rate but only when the rooms are occupied.

A simple step-by-step process would be much appreciated since I have tried using the Vistapro "Custom Variables Expressions" guide and Excel help and got totally lost.

[Complex Potential]

If you are not confident in using Excel I would highly recommend you invest some time in getting to grips with it. IES can generate vast quantities of data and sometimes you need the flexibility of a spreadsheet to deal with it all.

To answer your question, you can export up to I think 30 (ish) rooms on a single variable in one go for all hours in a year. If you have more than that limit in rooms you would need to export to excel multiple times.

Assuming all of the classrooms are on the same occupancy profile, then you only need to export one classroom with the people gains as a control for filtering unoccupied hours. The method I posted earlier can be scaled up for multiple rooms but it may take a bit of trial and error on your part I suspect.

Since the resulting sheet will be quite full you will then probably need to create the calculations on another sheet within the same document.

CP

[RossThompson87]

Hi,

I have created a spreadsheet for doing the excel calculations on multiple rooms.

It takes a bit of excel knowledge though, because IES exports the table in variable order not room order. So if you change the number of rooms you want to look at it gets messy.

I may be able to issue it but I'd need permission.

As Complex Potential suggests there is a limit to how much data IES can export, this is really frustrating on bigger projects.

Ideally the synopsis tool should have a when occupied tick box like the range test tool, if there are any developers watching....

[JohnM]

Hi iainsavage,

The custom variables feature allows you to create your filtered results.
I'm not sure what issues you're having but based on the information you have provided here's my example.

In the Manage Custom Variables dialog, i created one called 'Occupied Dry resultant temperature'.
I set input variable A to 'Number of people', and input variable B to 'Dry resultant temperature'.
I then used the expression: IF(A>0,B,NAN)

This i believe, creates one of the variables you're looking for.
The variable can then be copied, and modified so that input variable B is 'MacroFlo external vent'.

I hope this helps.

PS - You can also export room level variables to a csv file for use in Excel using the 'VistaPro > Export Results as CSV' menu option.

[btysoe]

Hi John,

using the export to csv function

is there a way or would it be possible for IES to transpose their data array? so the time steps go down and room variables go across?

excel is limited to 16,384 columns which limits the data to hourly readings (for a whole year).

[JohnM]

It's not currently possible in the VE, however i've passed on your suggestion to our feedback team.

I'm not aware of a way to transpose the data on import to Excel either.

Outside of the VE/Excel there are other methods/software to transpose CSV files.

[btysoe]

Hi John,

could you point me/us in the direction of the other method/software you have alluded to above?

I have tried a few things such as MS access, online utilities and even an attempt at writing some vba code all to no avail.
The problem with these method appears to be a lack of memory. Makes you appreciate the volume of data ies is dealing with.

would be very useful

thanks