Considering Thermal Performance At Every Stage of Design

Introduction

Architects and designers need to specify thermal performances of building elements including glazing during project stages. FenestraPro can assist where decisions need to be made at all stages of the design.

During schematic design, mass models may be analyzed and glazing variations compared with easy to read results using the application within Revit and by producing reports and charts for further review. Since a building façade can account for more than 50% of the energy costs, it makes sense that early consideration of envelope performance is implemented. FenestraPro Linc provides a database of Glass Types which may be assigned to the model at all stages and compare the implications on results.

FenestraPro Linc manages Glass Types in the model

The thermal performance of glazing, primarily to control conductive and radiant heat transfer, must be considered at an early stage of design as selections will affect heating and cooling loads and artificial lighting requirements. Glazing Performance can be summarized into three main values, the first two of which are the thermal components:

• Solar Heat Gain Coefficient: SHGC, or how much heat gain is generated inside,
• U-Value: how efficient the glazing is at controlling heat loss,
• Visual Light Transmittance: VLT, how much light is transmitted inside.

Part of the visible light transmitted will also contain heat which may be significant for buildings with large areas of glazing. There is a balance therefore to be struck between various factors such as making use of passive solar energy and daylight while controlling over-heating and glare. Glass emissivity will also determine the heat that is absorbed and radiated. Spacing of the glazing within the assembly as well as the gas will also affect heat gain.

Glazing properties indicate Thermal Performance

It may be useful at an early stage to use a simplified model such as a Conceptual Mass model to compare design options. It is advisable not to delay until the Detailed Design stage to begin Energy analysis as major changes at an advanced stage may have high cost implications to implement changes. FenestraPro provides various tools at all stages to assist in the design process.

Daylighting Results in FenestraPro reviewed alongside Revit’s Solar Analysis

Stages

At the Pre-Design stage, options for Massing Ideation and Form may be studied. Aesthetics, Orientation and the effects of the Urban Environment can also be reviewed.

At the Schematic Design stage, Massing Optimization, Spatial Organisation and Configuration of Openings may be considered. Goals may also be set for sustainable strategies to reduce energy use and lifetime costs. Thermal Performances of elements may then be reviewed once these design iterations are decided.

For both of these stages, FenestraPro provides Orientation Studies for Solar Radiation as well as assessing the Thermal Performance of the Building Envelope. The effects of Massing on the Percentage Glazing may also be examined during these stages as well as the effect of Daylighting in Internal Spaces may also be evaluated.

At the Design Development stage, Optimization of Openings may continue as well as Shading Solutions and Glazing Types to be employed. When openings are defined on the external walls, Thermal Performances may be considered.

FenestraPro also facilitates the consideration of Room Layouts and Core Spaces during the Design Development stage as well as the study of Shading Design strategies based on Solar Loads and Daylight. The Thermal Performance of glazing elements may then be defined once all dynamics are factored in (shading, fritting and surrounding objects).

During Construction Document stage, Materials and Finishes as well as Detailed Specifications can be defined, while Design Optimization may be finalized.

FenestraPro enables the Configuration of Glazing and the Specification of Glass, Framing, Curtain Panels and Walls by factoring in their thermal values to view the effects on Heat Gain and Daylighting. At all stages, Façade Configurations may be generated based on Performance Requirements and Comparative Analysis of Alternative Design Options may be considered.

FenestraPro Linc provides the ability to substitute Glass Types with different performance characteristics to review the effects on Heat Gain, Daylight and U-Value. Like Revit, applying a new Glass Type to a glazing instance will affect others in the model of that Revit family. You may manage window and curtain panel types in Revit if you wish to create several glazing types with different thermal properties.

FenestraPro Target also allows users to create Building Codes to test the performance of the building elements. Values may be input as performance targets for each element type and current model elements compared to these to indicate compliance.

Many designers may now choose also to consider passive design and go beyond the recommended Building Code values. If this is your strategy, the thermal performance of elements can be evaluated at the beginning of the design stages, even with mass models with simulated element values.

Conclusion

FenestraPro supports all stages of the design process by facilitating comparative studies and optimization of massing, form and orientation. Spatial organization and openings configuration may also be reviewed using the application and detailed studies of Thermal Specifications and Glazing Types.

Shading locations and overall dimensions may be factored in to modify Heat Gain results in both mass and detailed models. Building Code compliance may also be reviewed using custom values to evaluate whether current element values conform to target performances.

About FenestraPro For Revit

FenestraPro For Revit, a user-friendly platform that combines considerations for Daylighting, Thermal Performance and analysis of Solar Heat Gain, enables designers to maintain aesthetic control by early consideration of element performances.