Summary
This report presents the results of an investigation of the effectiveness of the provisions of Technical Guidance Document J (TGD J) regarding flue outlet locations for solid fuel burning appliances at preventing smoke particles entering the dwelling or neighbouring dwellings. Commissioned by the Department of Housing, Local Government and Heritage, the study responds to a number of queries received relating to smoke nuisance from an adjoining dwelling.
In this Computational Fluid Dynamics (CFD) modelling study, a ‘reference dwelling’ is defined in which a flue is located on a single storey, flat roof extension to the rear of the dwelling. Flue outlet emissions into the ambient environment were represented by a tracer gas. The study focused on a residential terrace of housing, with special attention given to the adjoining dwellings.
Scenarios were defined to evaluate flue outlet emissions in different environmental (wind speed and direction, and ambient temperatures) conditions to reflect winter months in Ireland. In addition, the impact of changing the flue outlet height was evaluated as this can impact localised dispersion of flue outlet emissions in colder conditions.
The findings confirms that tracer gas concentrations disperse by 99% within less than one metre of the flue outlet in parallel and oblique wind directions, with dispersion impacted by different local environmental and physical parameters.
Collaborators
This Technical Report is a part of Department of Housing, Local Government & Heritage (DHLGH) and Department of Enterprise, Trade and Employment (DETE) under the Irish Government’s Housing for All plan, and it has been Peer Reviewed through Construct Innovate in September, 2025.
Construct Innovate greatly values the work of the reviewers as their expert knowledge greatly contribute to the high standards of the Construct Innovate publications, therefore Construct Innovate thank the reviewers for their participation.
Principal Investigator
Dr. John Gallagher
Associate Professor (Civil Struct & Env. Eng.), Trinity College Dublin
Dr Gallagher is an Associate Professor in Environmental Systems Modelling and Director of TrinityHaus Trinity Research Centre in the Department of Civil, Structural & Environmental Engineering. He is also a Fellow of Trinity College Dublin (FTCD) and holds a Education for Sustainability Development (ESD) Research Fellow within the University. Since Dr Gallagher’s joined the Department, his research has focused on applying the 3M method (measurement, modelling and mitigation) to inform the development of passive engineered and nature-based solutions that deliver healthy indoor and outdoor spaces in a sustainable manner. His environmental pollution research focuses on reducing air pollution in and around buildings and transport hubs, improving environmental quality (air, noise and temperature) in urban green spaces. His work on low-carbon and resource efficient design of energy and infrastructure systems has informed contributions to standards development. Dr Gallagher has published over 50 papers in these areas in high impact international journals and international conferences, and to date he has been awarded over €1 million in research funding (from EPA, Research Ireland, SEAI, Erasmus+, INTERREG NWE & AA, and HORIZON 2020). He currently leads of a team of 9 researchers (6 PhD students, 2 postdoctoral researcher, and 2 research assistants). He has also produced professional research reports for a range of organisations in areas of water (EPA, An Foran Uisce), air pollution (Dept of Housing), low-carbon transitions (agriculture for Welsh Government, low-carbon buildings for Dublin City Council). Dr Gallagher also a member of a number of National and International research groups including the Environmental Science Association of Ireland, the Future Urban Ventilation Group, and was a member of the executive committee of the Universities Transport Studies Group as well as the U.S. Transportation Research Board ‘Air Quality and Climate Change’ committee. He is an Editor for the Discover Civil Engineering journal, acts as a reviewer for a range of journals, as well as international organisational report (World Health Organisation, World Green Building Council).
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