Gearoid Lydon | Swiss Federal Institute of Technology (ETH) (original) (raw)
Papers by Gearoid Lydon
This paper presents the design of a multifunctional floor element. The floor element integrates m... more This paper presents the design of a multifunctional floor element. The floor element integrates multiple functions, such as structural and energy related aspects. This integration reduces material use, related space requirements and embodied emissions. The element is optimised for embodied energy in the structural domain, by using a vault and fin structural form. With this method, a significant volume of concrete is replaced by expanded polystyrene insulation at locations that improve the structural and thermal performance of the element. In the energy systems domain, improvements to operational energy are provided by an active hydronic heating/cooling system and a passive thermal mass resource. The thermal performance design was driven by the use of computational fluid dynamics with conjugate heat transfer effects. The main advantage is a reduction in thermal losses by minimising the connection between the radiant panel and the structural supports. This increases the heat flow density, resulting in a lower supply medium temperature and an improved system efficiency of the radiant panel. This work provides design guidance to the development of improved lifecycle energy buildings.
Future buildings will require significant performance improvements to adhere to greenhouse gas mi... more Future buildings will require significant performance improvements to adhere to greenhouse gas mitigation strategies. One method is to consider building components as multifunctional elements. These elements can perform several functions simultaneously, such as energy and structural aspects. As opposed to traditional sequential design in which, each building element performs its own dedicated function. The former requires an integrated approach to prioritise the use of renewable energy sources and the reduction of materials. In this paper, we present three multifunctional elements: a lightweight shell roof, a funicular floor and an adaptive solar facade. We focus on the numerical simulation used to integrate thermally active building systems (TABS) and building integrated photovoltaics (BIPV) with lightweight structures. We outline a framework for the integration of the multifunctional element analysis with a dynamic building model and the performance factors of a district energy network. We exemplify the framework through the design of a real experimental building in Zurich, Switzerland. This delivered a net plus energy building (NPEB) with an annual weighted energy demand of 37.8 kWh/m 2 a and a weighted energy surplus of 45%. The results demonstrate the enhanced performance in terms of operational and embodied emissions.
Proceedings Fifth International Conference on Information Visualisation, 2001
Computational Modelling is a resource hungry discipline requiring extensive expertise and large a... more Computational Modelling is a resource hungry discipline requiring extensive expertise and large amounts of time. The ISO-STEP (International Standards Organisation -Standard for the Exchange of Product Model data) is proposing an integrated product model for CFD applications. This paper p resents a specification for a STEP compliant building product model for CFD analysis incorporating IBM's Open Source Visualisation.
This paper deals with the transport of momentum and heat inside and around a cavity exposed to a ... more This paper deals with the transport of momentum and heat inside and around a cavity exposed to a boundary layer type cross flow. A cylindrical tube rests on a flat surface over which a turbulent boundary layer is developed. The cavity is formed by the cylinder side wall and a disk of adjustable height, parallel to the flat surface. The disk acts as a continuous source of heat. Quantities of interest are the velocity and temperature fields inside and in the wake of the cylinder. These quantities were measured in a wind tunnel and calculated using FLUENT 5.5 for Reynolds number (based on cavity diameter)=1.44×104. The numerical mesh which was generated using GAMBIT1.3, is just under 400,000 nodes in size. It is a Hexahedral mesh taking advantage of GAMBIT's Multi−Axis Cooper Algorithm. The mesh was constructed with a boundary layer section and has a symmetry plane in order to reduce the computational effort. The numerical analysis was performed using FLUENT with the standard k−ε ...
In a European context, energy standards in the built environment have made a valuable contributio... more In a European context, energy standards in the built environment have made a valuable contribution to the sustainability of the industry over the past twenty years. The current cycle focuses predominantly on the thermal properties of the building envelope. As space heating and cooling with domestic water heating currently accounts for 60% of global energy consumption in buildings, this aspect will remain a key mechanism for building energy improvements. When considering 2050 energy targets, significant energy efficiency improvements will be required for new and renovated buildings in the next 5 – 10 years.
This research investigates the constraints placed on modern architecture by the influence of building energy regulation in the context of the HiLo module at NEST. Current building regulations are encouraging a convergence towards heavily insulated enclosures with minimised glazing, with the key design parameter being geometrical compactness. This assumes that the operational energy costs outweigh the costs of the embodied energy in the building materials and the construction process. As the building energy codes become increasingly severe for building designers, it is essential that innovation is central to architecture and regulatory assessment procedures become more sophisticated.
The goal of the HiLo module is to investigate if sustainable design related the total building lifecycle (BLC), rather than solely determined by an operational energy saving approach, will enhance architecturally and structurally challenging projects. This paper highlights the importance of the adaption of an early stage integrated design approach. In addition, it will demonstrate that considering the BLC will lead to more advanced sustainability focused outcomes for the built environment, without placing overbearing restrictions on architecture.
Building Simulation, 2013
Preventing airborne infections during a surgical procedure is of paramount importance for effecti... more Preventing airborne infections during a surgical procedure is of paramount importance for effective and economical delivery of care, as well as for health and well-being of patients. Ultra clean ventilation (UCV) systems are commonly used in operating theatres, in particular for orthopaedic surgery because of the higher risk of infection from exposed deep wounds. This research, investigates the airflow pattern of a UCV based operating theatre using computational fluid dynamics (CFD). The effects of the opening and closing of doors in two pressurisation scenarios (0 and 20 Pa) with the surrounding spaces at various inlet and door inflow velocities are investigated. The UCV system operates effectively in the positive pressure (20 Pa) scenario but fails when there is no pressure difference between the operating theatre and surrounding areas. The implications of the research findings are discussed in the context of design guidance and the operation of the airflow system.
This paper presents the design of a multifunctional floor element. The floor element integrates m... more This paper presents the design of a multifunctional floor element. The floor element integrates multiple functions, such as structural and energy related aspects. This integration reduces material use, related space requirements and embodied emissions. The element is optimised for embodied energy in the structural domain, by using a vault and fin structural form. With this method, a significant volume of concrete is replaced by expanded polystyrene insulation at locations that improve the structural and thermal performance of the element. In the energy systems domain, improvements to operational energy are provided by an active hydronic heating/cooling system and a passive thermal mass resource. The thermal performance design was driven by the use of computational fluid dynamics with conjugate heat transfer effects. The main advantage is a reduction in thermal losses by minimising the connection between the radiant panel and the structural supports. This increases the heat flow density, resulting in a lower supply medium temperature and an improved system efficiency of the radiant panel. This work provides design guidance to the development of improved lifecycle energy buildings.
Future buildings will require significant performance improvements to adhere to greenhouse gas mi... more Future buildings will require significant performance improvements to adhere to greenhouse gas mitigation strategies. One method is to consider building components as multifunctional elements. These elements can perform several functions simultaneously, such as energy and structural aspects. As opposed to traditional sequential design in which, each building element performs its own dedicated function. The former requires an integrated approach to prioritise the use of renewable energy sources and the reduction of materials. In this paper, we present three multifunctional elements: a lightweight shell roof, a funicular floor and an adaptive solar facade. We focus on the numerical simulation used to integrate thermally active building systems (TABS) and building integrated photovoltaics (BIPV) with lightweight structures. We outline a framework for the integration of the multifunctional element analysis with a dynamic building model and the performance factors of a district energy network. We exemplify the framework through the design of a real experimental building in Zurich, Switzerland. This delivered a net plus energy building (NPEB) with an annual weighted energy demand of 37.8 kWh/m 2 a and a weighted energy surplus of 45%. The results demonstrate the enhanced performance in terms of operational and embodied emissions.
Proceedings Fifth International Conference on Information Visualisation, 2001
Computational Modelling is a resource hungry discipline requiring extensive expertise and large a... more Computational Modelling is a resource hungry discipline requiring extensive expertise and large amounts of time. The ISO-STEP (International Standards Organisation -Standard for the Exchange of Product Model data) is proposing an integrated product model for CFD applications. This paper p resents a specification for a STEP compliant building product model for CFD analysis incorporating IBM's Open Source Visualisation.
This paper deals with the transport of momentum and heat inside and around a cavity exposed to a ... more This paper deals with the transport of momentum and heat inside and around a cavity exposed to a boundary layer type cross flow. A cylindrical tube rests on a flat surface over which a turbulent boundary layer is developed. The cavity is formed by the cylinder side wall and a disk of adjustable height, parallel to the flat surface. The disk acts as a continuous source of heat. Quantities of interest are the velocity and temperature fields inside and in the wake of the cylinder. These quantities were measured in a wind tunnel and calculated using FLUENT 5.5 for Reynolds number (based on cavity diameter)=1.44×104. The numerical mesh which was generated using GAMBIT1.3, is just under 400,000 nodes in size. It is a Hexahedral mesh taking advantage of GAMBIT's Multi−Axis Cooper Algorithm. The mesh was constructed with a boundary layer section and has a symmetry plane in order to reduce the computational effort. The numerical analysis was performed using FLUENT with the standard k−ε ...
In a European context, energy standards in the built environment have made a valuable contributio... more In a European context, energy standards in the built environment have made a valuable contribution to the sustainability of the industry over the past twenty years. The current cycle focuses predominantly on the thermal properties of the building envelope. As space heating and cooling with domestic water heating currently accounts for 60% of global energy consumption in buildings, this aspect will remain a key mechanism for building energy improvements. When considering 2050 energy targets, significant energy efficiency improvements will be required for new and renovated buildings in the next 5 – 10 years.
This research investigates the constraints placed on modern architecture by the influence of building energy regulation in the context of the HiLo module at NEST. Current building regulations are encouraging a convergence towards heavily insulated enclosures with minimised glazing, with the key design parameter being geometrical compactness. This assumes that the operational energy costs outweigh the costs of the embodied energy in the building materials and the construction process. As the building energy codes become increasingly severe for building designers, it is essential that innovation is central to architecture and regulatory assessment procedures become more sophisticated.
The goal of the HiLo module is to investigate if sustainable design related the total building lifecycle (BLC), rather than solely determined by an operational energy saving approach, will enhance architecturally and structurally challenging projects. This paper highlights the importance of the adaption of an early stage integrated design approach. In addition, it will demonstrate that considering the BLC will lead to more advanced sustainability focused outcomes for the built environment, without placing overbearing restrictions on architecture.
Building Simulation, 2013
Preventing airborne infections during a surgical procedure is of paramount importance for effecti... more Preventing airborne infections during a surgical procedure is of paramount importance for effective and economical delivery of care, as well as for health and well-being of patients. Ultra clean ventilation (UCV) systems are commonly used in operating theatres, in particular for orthopaedic surgery because of the higher risk of infection from exposed deep wounds. This research, investigates the airflow pattern of a UCV based operating theatre using computational fluid dynamics (CFD). The effects of the opening and closing of doors in two pressurisation scenarios (0 and 20 Pa) with the surrounding spaces at various inlet and door inflow velocities are investigated. The UCV system operates effectively in the positive pressure (20 Pa) scenario but fails when there is no pressure difference between the operating theatre and surrounding areas. The implications of the research findings are discussed in the context of design guidance and the operation of the airflow system.