Andrew Corney
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:
- Default Equipment, Lighting and Ventilation loads.
- 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% |
Wondering why the 5-day schedule for residential design. Seems that 7 days for both makes more sense
Thanks Megan - good point.
At the time, we made the change that way to avoid disruption to existing projects as much as possible. Unfortunately our way of doing templates is inflexible and couldn't be just changed for new projects but had to affect all existing ones too, which is why we have not changed it.
You can make your own 7-day space use template for residential within the application in the space use tab.