Changes to Plugin assumptions March 3, 2017

On March 3 we are making some substantial changes to a range of input assumptions in the Sefaira Plugin.

This document summarises the before and after state of the inputs for the plugin.

What has changed

Two things:

  1. Default Equipment, Lighting and Ventilation loads.
  2. Schedules. This is the % of internal loads applied hourly in the simulation. (usually high during occupied hours and low during unoccupied hours).

Combined, these may have changed your results and may affect your saved baselines if you included values for Equipment, Lighting and Ventilation.

Changes to Default Equipment, Lighting and Ventilation values

These values are in the plugin at the bottom of properties here:

They typically change with changes to building type:

or baseline:

Before March 3, our default values for the baselines did not match the default values for building types. This caused results between the plugin and the web app to be different.

The table below summarises what has changed here (metric units).

Building Type / Baseline Before March 3, 2017 After March 3, 2017
Ventilation  (l/s/p) Equipment (W/m2) Lighting (W/m2) Ventilation (l/s/person) Equipment (W/m2) Lighting (W/m2)
Office 15 25 10 15 25 10
Residential 10 5 10 10 5 10
School 10 10 15 10 10 15
Healthcare 4 air changes 15 20 6 air changes** 15 20
Laboratory 4 air changes 25 20 4 air changes** 25 20
Retail 3.5 15 15 10 15 20
ASHRAE 2010 5 (commercial) / 8 (residential)  10 (comercial) /    3.5 (residential)  8 (commercial) / 6.5 (residential)  Now all values are per space use type default above - this could mean a big change Now all values are per space use type default above - this could mean a big change Now all values are per space use type default above - this could mean a big change
ASHRAE 2013
ASHRAE 189.1
Part L - 2010      
Part L - 2013 N      

 

Changes to schedules

A more substantial change is to schedules. Most significantly, equipment, occupancy and lighting were all previously on 7-day schedules, with HVAC on a 5-day schedule. This has been aligned so both are on a 5-day schedule.

To make it easy to understand, we've summarised the average hourly % "on" for equipment, lighting and occupancy for each space type before and after the change in the table below. The 4th column shows how to modify your baseline default to get back pretty close to what you had before in terms of absolute equipment and lighting loads.

Space Use Name Before March 3, 2017 After March 3, 2017 % to increase load by
Office 27% 24% 14%
Residential 44% 27% 63%
School 25% 21% 19%
Healthcare 58% 33% 79%
Laboratory 42% 34% 24%
Retail 24% 20% 22%

 

 

 

 

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