Welcome to the Sefaira monthly product update. Over the past month of May, we made some important improvements to our products. Read on to learn more.

New Features

Detailed Perimeter / Core Zoning

Perimeter / Core zoning is the default zoning strategy in the web application. It’s a great way to zone a building with minimal effort to improve the accuracy of results. Sefaira supports two Perimeter / Core zoning modes: Basic and Detailed.

thermal zones


Zones are grouped by orientation. Consider the image above: zones P09 and P07 would be considered part of a single thermal zone. This is an efficient way to define and consider zones, but limits granularity in analysis.


Each non-contiguous space is it’s own zone. Consider, again, the image above: zones P09 and P07 are considered as unique zones. This enhances the granularity of analysis.

Air Source Heat Pumps (Sefaira Systems only)

There is a new heating hot water loop option called “Heat Pumps”. This represents an air-source heat pump which is a device that extracts heat from the air to generate heating hot water.

This was a very popular feature request but was not native to EnergyPlus. We therefore integrated the performance curves into the idf file separately.

The solution is dynamic, considering external air temperatures and supply water temperatures in determining the effective hourly COP of the device. Watch this space for more details and documentation.

Operative Temperature

The comfort output tab now does two calculations when you turn comfort on: Operative Temperature (also known as Resultant Temperature) as well as Dry Bulb Temperature.

Operative temperature differs from dry bulb temperature in one key way: when considering operative temperature, you need to set the range you’re trying to achieve for all zones. (Dry bulb temperature uses the setpoint range in each zone to work out the threshold that you’re trying to hit.)

Many would argue that operative temperature is a better measure of comfort but note that because operative temperature includes radiant temperature, heavily glazed perimeter zones can be expected to have trouble passing even if a building is conditioned. This is because the radiant temperature (which makes up half of the operative temperature) is high.

We’ll be publishing more guidance on operative temperature soon.

Energy Breakdown Graph includes “Energy Mix” views for cost and CO2

You can now swap between an Energy Use and Energy Mix breakdown of the building’s energy use in the Energy Breakdown graphics.

This is especially helpful to create views for projects aiming to achieve net zero energy cost or net zero CO2 emissions because the renewable portion can be separated out of the energy use.


Editable Values for Response Curves

We have had lots of requests to change slider ranges for response curves. In the end, we decided to make the two ends of the response curve range manually adjustable with the slider showing “Typical” values.

If the value is outside the “typical range” the box will go red but it will still use those values.

Placement of Zone Names

We adjusted where we place the zone names to make it easier to identify which zone is which.

Formatting Ignored Zones

Ignored zones are now colored grey to clarify which ones have been ignored.

Staying Up to Date

You can receive product updates and other Sefaira articles by signing up for our newsletter at sefaira.com. You can also follow product development throughout the month on the Sefaira Knowledge Base.