'A Programme of Testing to Evaluate a Passive Approach to Whole House Ventilation' Journal of Construction Innovation, Information, Process Management. Special Issue, Volume 10, Issue 3, 2010. ISSN: 1471-4175
A long standing research interest of mine is the achievement of a passive and low-energy ventilation system as an alternative to mechanical ventilation strategies. My interest began with an EPSRC funded project to optimise a key component of this system, the Supply Air Ventilated window (SAW), which also became the topic of my PhD. By combining SAWs with self-regulating vents and a passive stack ventilation (PSV) system a totally passive way of achieving ventilation heat recovery can be achieved.
This paper describes a programme of research into this innovative approach to whole-house ventilation with heat reclaim. In order to save energy houses are now required to be constructed to a high level of air-tightness. This poses potential problems of indoor air quality, condensation and mould growth, with implications for human health. Adequate and controlled ventilation is a necessity, in Europe the adoption of mechanical systems incorporating heat reclaim has become the preferred technology. The relatively mild climate of the UK undermines the efficiency of these fan-driven solutions. The programme of research has been to test the viability of an engineered system of natural ventilation for use in temperate regions.
The system works by the combination of ‘supply-air’ windows and passive stacks. The windows have an air path for incoming ventilation that passes between panes of glass, the pressure drop across the windows to induce the air flow through them is provided by the passive stacks in kitchens and bathrooms. Passive stacks are an alternative to the use of extract fans; they have been included in the building regulations since their efficacy was proven by research carried out at the BRE (Building Research Establishment) in the 1980s. ‘Supply-air’ windows are manufactured in Finland, and have also been researched in Canada. The research described in this paper is the first to combine ‘supply air’ windows and passive stacks to form a system that is completely natural and operates without the use of electricity. It has been carried out over the course of a number of projects. Beginning with laboratory studies that established the design dimensions for the windows, followed by test cell measurements; and installation in real buildings monitored both empty and occupied. Each stage was validated in relation to simulation models.This research also led to the formation of a company called Dwell-Vent Ltd with Prof. Mike McEvoy, also of the University of Brighton College of Arts and Humanities.