Scalable method to assess ventilation rates in dwellings

TKnowledge of air exchange rates in existing buildings is increasingly important, especially in the context of retrofit. Retrofit interventions to improve the energy efficiency of a dwelling will most likely lead to a reduction in air exchange through infiltration, and it is important to ensure that this does not negatively impact the overall background ventilation rate in the building.

There are many established techniques for measuring and characterising air exchange rates in buildings. Despite this, there is currently very little data available regarding ventilation rates of existing dwellings in the UK. This is partly due to the complexity and cost of deploying established techniques, e.g. tracer gases, at scale.

However, through the increasing uptake of smart thermostats it is likely that temperature and humidity data will be available for large numbers of dwellings in the future. This project aims to explore how this data can be used to estimate ventilation rate. Provided both internal and external hygrothermal conditions are recorded, the resulting vapour pressure excess, i.e. moisture content rise above external levels, can be derived. Since vapour pressure excess is effectively a function of internal moisture generation and ventilation effectiveness, estimates of ventilation rate can theoretically be made using vapour pressure excess.

The low carbon energy systems needed to achieve the Government's carbon 2050 reduction targets promise declining generation costs, but at the price of inflexibility and intermittency. The challenge is to contain costs and improve energy system security, by building in resilience. The opportunities include: more efficient energy conversion, networks and storage technologies; improved energy control and management systems; integration of energy performance into modern methods of construction; improved measurement, display and control systems; and new business models. This will bring pervasive economic benefits: the creation of new intellectual property and expertise; businesses with the ability to compete in the huge new markets for energy efficiency and resilience, both in the UK and overseas; healthier and more productive places to work and live; and a means to address social hardship and inequalities, such as fuel poverty, which affects the health and wellbeing of society's most vulnerable. Seizing these opportunities requires leaders with multi-disciplinary knowledge, skills and whole-system perspective to break down restrictive, sector-specific silos, and drive innovation. The ERBE CDT will train such leaders.

The short and medium term impacts of the ERBE CDT will arise during the training of these leaders and through their research outputs and collaborations. These will include, but are not be restricted to: new approaches to analysis; new insights derived from large datasets; new modelling methods and ways of using existing models; new experimental techniques; field and laboratory measurement techniques; improved socio-technical methods; new manufacturing methods, devices, primary data sets, and patents; and, together with our industrial stakeholders, the integration of research into the business innovation process.

The longer term impacts will be realised over the next 40 years as ERBE graduates take on influential roles in diverse organisations, including:
- national and local governmental organisations that are developing affordable and socially acceptable evidence-based energy policies;
- energy supply and services companies that are charged with delivering a clean reliable and economical system, through deployment of energy efficiency products and technologies within an evolving energy system architecture;
- technology companies that are developing new components for energy generation and storage, new heating, cooling and ventilation systems, and smart digital controls and communications technology;
- industries that are large consumers of fuel and power and need to reduce their energy demand and curb the emission of greenhouse gases and pollutants;
- consultancies that advise on the design of energy systems, non-domestic building design and urban masterplans;
- facilities managers, especially those in large organisations such as retail giants, the NHS, and education, that are charged with reducing energy demand and operating costs to meet legally binding and organisational targets;
- standards organisations responsible for regulating the energy and buildings sectors through the creation of design guides and regulatory tools;
- NGOs and charities responsible for promoting, enabling and effecting energy demand reduction schemes;
- health and social care providers, who need to assure thermal comfort and indoor air quality, especially as our population ages and we adopt more flexible healthcare models.

The realisation of these benefits requires people with specific skills and an understanding of the associated ethical, health & safety, regulatory, legal, and social diversity and inclusion issues. Most importantly, they must have the ability to look at problems from a new perspective, to conceive, and develop new ideas, be able to navigate the RD&D pathway, and have the ability to articulate their intentions and to convince others of their worth; the ERBE CDT will develop these capabilities.