Controlled active mass for offices with god thermal comfort and low environmental impact

Project description
A two years project financed by Formas will be undertaken in the cooperation between SP, Chalmers and University of Gävle. The purpose of this project is to evaluate how the use of controlled active mass (CAM), in an office building, should be constructed and controlled in order to generate a better thermal climate with low energy usage. The objective with CAM is to accomplish an improved indoor climate and enable an increased use of energy sources with low environmental impact. Since office buildings often have large temperature variations during the day the building framework will act as an energy-storing mass (passive mass) and damp these effects. The energy-accumulating mass in CAM will consist of water where the capacity could be varied (controlled) depending on the demand. A CAM system will contribute to an improved thermal comfort and also to reduce the buildings affect on the outer environment. Most previous simulation has always been on light or heavy buildings with a fixed thermal mass in form of walls, floors and roofs. A CAM system can be places in the room and do not have the same mass during the time.

CAM will be evaluated through full-scale measurements in a test chamber, design as an office building where it will be verified and studied in conjunction with different ventilation principles in order to achieve a complete system that provides a good indoor climate. As a complement to the measurements numerical calculations will be performed. Computational Fluid Dynamics (CFD) will be used for a detailed evaluation of the indoor climate and the calculation of the temperature distribution and the airflows in the premises. The energy simulation program IDA and/or HAM-tools will be applied for the examination of the annual energy usage of the building.

Thesis work
In the frame of this above described main project there will be three master thesis works of 20 credits available each covering different aspects and questions. The thesis works can be performed as one 20 week project for one or two students. For two students more cases will be investigated. Below you will find a more detailed description of each project.

Thesis work A -CFD
This thesis work will mainly focus on numerical predictions using Computational Fluid Dynamics (CFD) of the heat transfer and performance of different designs of the CAM installation. This includes the comparison of different geometrical constructions as well as the locations of the CAM installation in order to finding the most efficient installation that provides a good thermal comfort in an office premises. The software Gambit/Fluent will be used in the project. This project will be carried out in near collaboration with the thesis work B where the results from the CFD simulations might be used as input for the construction of the physical installations that should be used in the measurements. Wise verse could the results from thesis work B be used as input into A. The location of this thesis work will be at SP in Borås.

Thesis work B –Experimental study
This thesis work is mainly devoted to performing experimental measurements and visualisations using different techniques. Available measuring techniques that might be used are; hot wire anemometry (HWA), Laser Doppler Anemometry (LDA), Particle Streak Velocimetry (PSV), Particle Image Velocimetry (PIV) and IR camera. The focus of the work will be to compare different designs of the CAM installation regarding the resulting heat transfer and surface temperatures. This thesis work will be undertaken at the University of Gävle where all the measuring equipment are available.

Thesis work C –Energy simulations (Building Physics)
This thesis work is focused on the overall energy usage of an office that have installed a CAM system. This includes the modelling of a complete office including persons, computers and other thermal loads as well as the impact from incoming solar radiation. Most simulationsw