Revit Sunrise: Divide and Conquer – Thermal Zoning the Analytical Energy Model

We continue to improve energy analysis tools in Revit and have improved automatic thermal zoning in the Revit Sunrise hosted preview. In some cases this will improve the accuracy of the energy analytical model. Best of all you don’t have to be an energy engineer to use thermal zoning – it’s automatic!

What is thermal zoning?

You may be familiar with ‘HVAC system zoning, where systems are split up by the design engineer for efficiency, scale and control of specific spaces but thermal zoning is different. Thermal zoning accounts for the variation in heat gain/loss through the building envelope due to different orientations by dividing the envelope perimeter into smaller spaces.

Here’s a diagram of building forms divided into thermal zones.

 

Our example shows diagrams of large open spaces and the resulting energy analytical model of those un-zoned spaces would be inaccurate. Our zoned energy analytical model is comprised of discrete perimeter analytical zones and a single internal zone representing a more accurate energy model.

It’s worth mentioning that an energy model from Revit building elements that aren’t a large open plan is already thermally zoned or at least partially zoned. An energy model created from the building layout shown below would provide sufficient zoning due to separations from the numerous walls.

 

Revit Floor Plan

 

Energy Analytical Spaces – Lots of spaces from wall divisions

When to Thermal Zone?

The answer is simple – always! Even though some models can get their zoning from wall divisions, there’s no such thing as an ‘over-zoned’ analytic energy model. Additional analytical spaces in your energy model will not decrease analytic accuracy.

What has changed?

The new thermal zoning improvements are only available when using the Analysis Mode ‘Use Conceptual Masses and Building Elements’ setting from the Energy Settings dialog.

‘Use Building Elements’ and ‘Use Conceptual Masses’ analysis modes are unchanged from previous releases.

Using Thermal Zoning

Using thermal zoning is simple and is the default behavior in Revit utilizing existing Energy Settings parameters.

1. Analysis Mode: Select ‘Use Conceptual Masses and Building Elements’. Hint: This mode can be used with Revit masses, building elements or a combination.
2. Core Offset: Use the default value or set your own.
3. Divide Perimeter Zones: This parameter will divide the building perimeter as described above.

Summary

That’s it - thermal zoning in Revit is simple and automatic! Please let us know if you have any comments or suggestions for improvement.