An optimised and proactive maintenance strategy aims to maximise the economical profit, minimise environmental impacts and keep the risk of failure to a low level. Implementation of such strategy in the context of district heating requires efforts and abilities for predicting future performances and estimating service life of district heating components. A literature review on failures (damages and performance reductions) occurring on district heating pipes, reveals that failures in district heating pipes are mainly leaks due to corrosion or mechanical impacts and reduced thermal insulation performance: leaks being the more serious damage type. A feasible service life estimation method for this type of damage is the Factor Method. Since the application of this method within the context of DH pipes has not been found in other publications, this paper focuses on describing the method and discusses the possibilities on how to apply it in two specific cases with respect to leakage: service life estimation of repaired district heating pipe sections (i.e. maintenance of district heating network) and of district heating pipes in new or extended district heating networks. A particular attention is paid on which modifying factors to consider and how to quantify them.

Construction works are in periodical need of performance upgrade such as maintenance, repair and rehabilitation (MR&R). Facility managers are responsible to fulfil this need during the whole life cycle of the construction works in a manner that maximises the economical profit, minimises the environmental impact and keeps the risk of failure at a low level. A prerequisite for efficient facility management (FM) is long-term planning of MR&R actions. This requires management of a large amount of information, a process that includes gathering, storing, processing and presentation of data. With the development of open Building Information Models (open BIM) and standardisation of Industry Foundation Classes (IFC) new possibilities of efficient management of FM information have emerged. Due to its parametric and object-oriented approach, the open BIM-concept rationalises the information management and makes it more cost effective. This paper discusses how open BIM, with the aid of IFC, and Product Life Cycle Support (PLCS) may facilitate the implementation of a predictive Life cycle Management System (LMS) and by that improve the feasibility for adopting long-term and dynamic maintenance strategy in the FM process. A case study on the use of a commercial BIM-based design tool as information repository and media to present life cycle information within the context of the LMS concept on a hospital building is also presented. The case study shows that the build-up of the information becomes simpler, more clear and efficient compared to a traditional database solution, as it is done with parametric objects. However, the basic BIM can not serve for all LMS functions. There is still need for development of a BIM integrated LMS solution that may support prediction of life cycle performance and maintenance needs. Such a solution needs to be communicative to any open BIM software and thus has to be built upon open standards for exchange of building information, e.g. the IFC standard, and life cycle oriented standards like PLCS. Additional focus is put on 4D simulation and visualisation. Simulation and visualisation of long-term performance of buildings is of crucial importance when improving the feasibility for adopting a long-term and dynamic maintenance strategy in the FM process. © 2011 The authors.

This paper presents the thermal modelling of an unglazed solar collector (USC) flat panel, with the aim of producing a detailed yet swift thermal steady-state model. The model is analytical, one-dimensional (ID) and derived by a fin-theory approach. It represents the thermal performance of an arbitrary duct with applied boundary conditions equal to those of a flat panel collector. The derived model is meant to be used for efficient optimisation and design of USC flat panels (or similar applications), as well as detailed thermal analysis of temperature fields and heat transfer distributions/variations at steady-state conditions; without requiring a large amount of computational power and time. Detailed surface temperatures are necessary features for durability studies of the surface coating, hence the effect of coating degradation on USC and system performance. The model accuracy and proficiency has been benchmarked against a detailed three-dimensional Finite Difference Model (3D FDM) and two simpler ID analytical models. Results from the benchmarking test show that the fin-theory model has excellent capabilities of calculating energy performances and fluid temperature profiles, as well as detailed material temperature fields and heat transfer distributions/variations (at steady-state conditions), while still being suitable for component analysis in junction to system simulations as the model is analytical. The accuracy of the model is high in comparison to the 3D FDM (the prime benchmark), as long as the fin-theory assumption prevails (no 'or negligible' temperature gradient in the fin perpendicularly to the fin length). Comparison with the other models also shows that when the USC duct material has a high thermal conductivity, the cross-sectional material temperature adopts an isothermal state (for the assessed USC duct geometry), which makes the ID isothermal model valid. When the USC duct material has a low thermal conductivity, the heat transfer course of events adopts a 1D heat flow that reassembles the conditions of the 1D simple model (for the assessed USC duct geometry); ID heat flow through the top and bottom fins/sheets as the duct wall reassembles a state of adiabatic condition.

The Life Cycle Management System (LMS) aims at supporting decision-makers and engineers in their efforts to achieve a more optimised proactive life cycle design and maintenance management strategy. LMS is an open and integrative system, which has to be adapted and developed in order to meet the needs and requirements of users. This process should be geared to and governed by the clients. The Architecture, Engineering, Construction and Facility Management (AEC/FM) sector includes all varieties of clients and stakeholders, all of them having different qualifications, possibilities and requirements for implementing, or increasing the feature of predictive maintenance management and optimised proactive strategies. The possibilities of adopting predictive maintenance management are dependent on the availability of performance-over-time and service life forecasting models and methods. The relevance of these models and methods depends on the required level of detailing. Furthermore, the use of the models and methods depends on the availability of reliable input data, such as material data and environmental exposure/in-use condition data. The thesis aims at analysing the possibilities of implementing predictivity in different fields of applications and at evaluating relevant tools facilitating management of information associated with predictive maintenance management systems. The thesis includes studies of three different clients and fields of application; Swedish Road Administration – management of bridges, Locum AB – management of hospital buildings, and Gävle Energi AB – management of district heating distribution systems. While the Swedish Road Administration is responsible to ensure an economically efficient, sustainable transport system for the society throughout the country, Locum AB and Gävle Energi AB compete on an "open" market. The Swedish Road Administration have gathered information about their bridges since 1944, for what reason their bridge management system includes a large amount of valuable data for performance-over- time analyses and service life forecasting. Locum AB has recently begun to systematically gather condition data, why the amount of data is limited. However, since the performance of buildings generally is well known, it is assumed that possibilities of implementing predictive maintenance management tools are rather good. Since district heating pipes are buried into the ground, it is difficult to assess the condition. Therefore, data for service life estimation rely mainly on damage reports. Environmental exposure data on macro or meso level can be obtained from meteorological and environmental institutes, thus making it possible to apply available dose-response and damage functions. Environmental exposure data on a micro level are lacking. Guidelines, methods and tools for environmental measuring and modelling on a micro level are therefore strongly needed. Efficient management of information plays an important role in predictive life cycle management systems. The ongoing development and implementation of open Building Information Model (BIM) tools in the AEC/FM sector is a promising progress of making the information management more cost effective and valuable, especially when open BIM solutions being fully integrated into the AEC/FM business. Geographical Information Systems (GIS) are tools for efficient handling of spatial positioned information. GIS provide possibilities of processing and presenting, e.g., environmental exposure data and environmental risk factors.

Construction projects include large amounts of information that has to be communicated to a number of actors, such as authorities, companies, clients and end users. Information exchange is complex, involving various players on different levels and phases of the construction process. For private clients, who generally have little experience and knowledge of this process, the on-going “Bygga Villa”-project has developed a web-portal, which offers them relevant information about the process and a number of services to facilitate realisation of their projects. One of the services provides a tool for supporting long-term strategy planning. The tool is based on the Life cycle Management System (LMS) that is a predictive and generic life cycle-based management system, aimed to support decision-making and planning of optimal design and maintenance of any construction works. The LMS-Bygga Villa tool estimates service life and maintenance intervals of different building parts and systems based on environmental-dependent degradation models. Simulated scenarios can give optimised solutions by applying life cycle cost analysis. This paper presents two case studies within LMS-Bygga Villa. The first case focuses on service life performance analysis of exterior parts of buildings. The second focuses on service life performance analysis of energy systems; here specifically a borehole assisted heat pump system used for heating a Swedish single-family residence.

Over the last decades, installation and use of heat pumps has grown rapidly in Sweden, to the extent that these mainly or partly heat roughly 25 % of the heated floor space in single-family houses. A majority are ground coupled where the heat exchanger is a borehole of 60-220 m depth. As the heat pump system operates, heat extraction will in time reduce borehole temperatures, rendering lowered efficiency of the heat pump system thus directly affecting its economical and environmental aspects. Within the building sector, durability and life performance dynamics of energy systems is often not reflected upon. System performance and efficiency is assumed to be static over time, changing only due to different operation scenarios. This paper serves to quantify the long-term thermal performance degradation of a component, in this case the borehole, and how the degradation of this component affects performance-over-time of an entire system, in this case the heating system of the building. A dynamic thermal simulation model is used to assess the long-term thermal performance of the borehole. The building, which the heat pump serves, is assumed to be a typical Swedish house with normal energy consumption. Simulation results show that the depth of the borehole is of great importance to limit over-time temperature drops. The efficiency of the heat pump system is directly dependent of temperatures in the borehole. How the overall system performance is affected by component performance degradation, is highlighted.

The objective of this report is to derive an analytical and numerical USC model for thermal analysis. These models are meant to calculate USC temperature variation across the USC duct as well as the fluid temperature along the USC. The main purpose of the analytical model is to attain a detailed steady state tool for USC (as in this report) design and dimensioning. The numerical model is meant to calculate the time dependant USC thermal performance as well as being a benchmark for the analytical model.

The Swedish Road Administration (SRA) has developed an information technology (IT) based bridge and tunnel management system (BaTMan) that is widely implemented by the organisation. The system is a tool for operational, tactical and strategic management. However, this system does not include systems and tools for managing optimisation and long-term planning of␣Maintenance, Repair and Rehabilitation (MR&R) actions due to service life performance aspects. This paper discusses the need of service life performance analysis for sound optimisation and long-term planning of MR&R actions in the bridge management. The paper presents a service life performance analysis model that is based on a Markov chain model and the MEDIC method. The model is developed to manage different kinds of degradation characteristic and yet present a uniform result expressed in conditional probabilities. The paper discusses also the need of systems and tools for describing objects on both an overall level and on a component level.

Samtidigt som fjärrvärme är ett effektivt sätt att leverera värme så leder en centraliserad värmeproduktion till att fler personer drabbas vid eventuella driftavbrott. Detta skapar ett behov av ökad leveranssäkerhet och kontroll av prestanda över hela fjärrvärmenätets livscykel. Genom en långsiktig planering av nätets utbyggnad och förvaltning erhålls effektivare resursanvändande och större säkerhetsmarginaler. Långsiktig planering bygger till stor del på analys av olika scenarier där såväl rådande förutsättningar som ”worst cases” kan beaktas utifrån olika aspekter (tekniska, ekonomiska, säkerhetsmässiga m.m.). Målet är att hitta optimerade åtgärder, vilket kräver systematisk hantering och bearbetning av en stor mängd information. Detta kan endast göras rationellt med hjälp av IT-verktyg. Life cycle Management System (LMS) är ett resultat av tre konsekutiva EU-finansierade forskningsprojekt där gruppen för byggnadsmaterialteknik – Högskolan i Gävle, har haft en ledande roll. Systemet innehåller utvecklade rutiner och metoder för hantering av information som ligger till grund för långsiktig planering och optimerad förvaltning av byggnadsverk. Systemmässigt är LMS uppbyggt av moduler som hanterar och analyserar data på olika sätt. Anledningen till systemets modulbaserade struktur är att det, helt eller i delar, kan anpassas mot de krav och önskemål som klienten ställer på systemet. På så sätt behöver klienten bara komplettera sitt befintliga system med de funktioner som önskas av LMS, samtidigt som denne undviker att ”kasta ut” det gamla systemet. Förstudien omfattar en litteraturstudie och analys av Gävle Energi AB:s (GEAB) drift- och underhållsdata. Förstudiens syfte är att identifiera och kartlägga de anpassnings- och utvecklingsbehov som föreligger en implementering av LMS som planeringsverktyg för GEAB:s fjärrvärmenät.