Content area
Full Text
ABSTRACT
ASHRAE RP-1383, "Develop a Radiant System Module for the Simulation and Analysis of Spaces and Systems," produced analysis procedures that allow calculation and display of comfort conditions at any point within a room. These procedures are implemented in a PC-based application called Radiant Performance Explorer (RPE), an enhanced version of the ASHRAE Thermal Comfort Tool.
The project developed a method for calculating view factors from an arbitrarily positioned occupant to all surfaces of an arbitrarily shaped space. With this general ability and knowledge of room surface temperatures, mean radiant temperature (MRT) can be calculated for any occupant position This in turn allows derivation of common comfort measures such as predicted mean vote (PMV) and predicted percentage dissatisfied (PPD). Other radiant values, such as radiant temperature asymmetry, are also calculated. RPE displays these results in a computer-graphics-based visualization screen.
RPE can import and display data generated by the three-dimensional (3D) drawing tool, SketchUp; the building energy simulation application, EnergyPlus; or other sources. Export of comfort results is available.
The project also enhanced EnergyPlus to more flexibly model controlled-temperature panels.
(ProQuest: ... denotes formulae omitted.)
INTRODUCTION
This paper documents ASHRAE Research Project (RP) 1383, "Develop a Radiant System Module for the Simulation and Analysis of Spaces and Systems."
The primary tangible result of the project is the Radiant Performance Explorer (RPE), a Microsoft® Windows® application that calculates and displays comfort results for multiple positions within an arbitrarily shaped room. RPE is an enhanced version of the ASHRAE Thermal Comfort Tool (ASHRAE 2011) and is implemented in C++.
The technical heart of the work is the development of a method that calculates view factors from an arbitrarily positioned occupant to all surfaces of an arbitrarily shaped space. The method supports any number of room surfaces, each with any number of child surfaces (e.g., windows or radiant panels). The space and its surfaces can be nonconvex so that troublesome cases such as L- or U-shaped rooms can be analyzed. Situations where direct-beam sunlight strikes the occupant are also identified.
With this general ability to derive occupant-to-surface view factors (and knowledge of room surface temperatures), mean radiant temperature (MRT) can be calculated at an arbitrary occupant position. This in turn allows derivation of common comfort measures, such as...