Course leader: Moga Ligia Mihaela
Home Institution: Technical University of Cluj-Napoca
Course Overview
Based on the requirements of the last energy performance of buildings Directive (EU) 2018/844, nearly Zero Energy Buildings (i.e. nZEB) levels defined for new buildings, must also be met by existing buildings. Therefore, a thorough approach must be given in design or retrofit stage of the building envelope. It is well known that thermal bridging is an important consideration in high
performance energy efficient buildings (e.g. nZEBs, passive buildings, active buildings and others).
Although that the thermal envelope is usually all covered in insulation, proper design using modelling and simulation tools is a must for reaching proper thermal performance indexes. Participants will learn the fundamentals of thermal bridging calculations for various types of building joints, respectively common junction details and their modelling conventions will be examined. The validated software THERM will be taught for the implementation of modelling techniques. Participants will be given the opportunity to perform calculations and have them reviewed in class.
An introduction to the science of coupled heat and moisture analysis will be done. A get hands on training using the validated hygrothermal modelling software WUFI®, will be addressed, in order to learn how to carry out a hygrothermal analysis and how to effectively interpret the results.
The course is useful for students and other building professionals (i.e. architects, engineers, building envelope consultants, building energy modelers) that wish to understand and quantify both thermal bridging and hygrothermal performance of building envelope components..
Learning Outcomes
By the end of the course, students should be able to:
• Identify legislation in the field of buildings energetics (i.e. energy efficiency,
energy performance of buildings)
• Identify passive design strategies for nZEBs
• Define and identify types of thermal bridges at buildings
• Modell and simulate various types of thermal bridges
• Gain practical experience in the calculation of thermal bridging heat loss
• Understand the concepts behind initial conditions, moisture and heat sources
and sinks
• Do a hygrothermal modeling of the building envelope components
• Develop a suitable approach for optimizing buildings joints
Course Content
1. Types of high-performance energy efficient buildings and associated design requirements.
2. Presentation of the passive design strategies for buildings with a focus on the building envelope compliance
3. Introduction to thermal bridging: definitions, types of thermal bridges, problems associated with thermal bridges, significance of thermal bridges in energy assessments, case studies from current practice.
4. Thermal bridges modelling protocols: overview of modelling approaches, boundary conditions, geometrical models, materials properties, geometrical model discretization approach
5. Steady state formulations – discretization and implementation in Excel
6. Therm software presentation. Modelling of exterior and interior corners
7. Modelling and simulation of rim joists, roof eaves.
8. Modelling of windows-wall connections: parapets, sill, header, jamb
9. Modelling of unheated basements constructive details, foundations slabs and
foundations footings.
10. Usage of Psi values in other available software: Wufi Passive, PHPP
11. Theory of coupled heat and moisture science. Hygrothermal modelling of heat flow and moisture using WUFI software. Simulation set up: component assembly and numeric grid, material data, weather data
12. Hygrothermal calculations using WUFI. Results interpretation: display, courses, profiles. Case studies in WUFI using previously modelled construction details in THERM.
Course Lectures 1-2: 4 hours
Course Lectures 3: 4 hours
Course Lectures 4: 2 hours
Course Lectures 5: 2 hours
Course Lectures 6: 2 hours
Course Lectures 7-8: 2 hours
Course Lectures 9-10: 2 hours
Course Lectures 11: 2 hours
Course Lectures 12: 2 hours
Each course will also have allocated the application part (i.e. seminars) in a total sum of 20 h.
Assessment of the building’s systems will not be addressed during the application part due to time constraints.
Instructional Method
The course will be divided in 22 h of lectures and 20 h of seminars.
The lectures will include theoretical knowledge regarding points 1-12. The knowledge will include up to date information regarding the addressed topics.
Seminars (i.e. application part) will include modelling and simulation of case studies for both new building and existing building. Time will be allocated for the presentation and utilization of available commercial software. Application will be made in Excel,
THERM and WUFI software. Implementation of obtained results will be used for a buildings case study.
Group project: students will be divided in groups (2 to 3 students) for more sustainable use of time, in order to reach the aim of the course applications. The group will focus on several case scenarios following the recommendations from course 4-12.
The final class will include the submission and a brief presentation of the obtained results for the modelled and simulated cases.
Required Course Materials
Read the reference text:
OVERVIEW | Zero-Energy Buildings: does the definition influence their design and implementation?
Directive (EU) 2018/844 of the European Parliament and of the Council of 30 May 2018 amending Directive 2010/31/EU on the energy performance of buildings and Directive 2012/27/EU on energy efficiency Thermal Bridges –Theory and Standards, Stephen Burke, PhD, Qualified Technical Specialist, NCC Ilomets, S., Kuusk, K., Paap, L., Arumägi, E., & Kalamees, T. (2017). Impact of linear thermal bridges on thermal transmittance of renovated apartment buildings, Journal of Civil Engineering and Management, 23(1), 96-104. Brumă B., Moga L, Moga I., Aspects regarding dynamic calculation of plan building
elements having thermal bridges, Sustainable Solutions for Energy and Environment, EENVIRO - YRC 2015, 18-20 November, 2015, Bucharest, Romania
You are required to bring a laptop, so that you will be able to familiarize yourself with the software used in this course applications.
THERM software https://windows.lbl.gov/software/therm
WUFI® Plus https://wufi.de/en/software/wufi-plus/
Assessment
Quizzes: 2 quizzes used for assessing the gained knowledge during the course. Each quiz will represent 15% from the final grade.
Assignment: each student or group of students (i.e. 2-3 students/group) will choose a project from which building joints will be modelled and simulated using THERM and WUFI software.
Presentation: final presentation of the modelled cases and submission of the researched cases (65% of the final grade)
Feedback: providing feedback at other students’ presentation (5% of the final grade)