Measuring the ventilation rate in occupied buildings and adapting the CO2 tracer gas technique

Measuring ventilation rates in occupied dwellings is challenging but represents the conditions that occupants experience. This paper explores the constraints of existing methods when measuring the ventilation rate of occupied buildings and proposes a new method addressing some of them.  

Airtightness and non-uniformity of ventilation rates in a naturally ventilated building with trickle vents

Infiltration is an uncontrolled contribution to ventilation in a building and can contribute significantly to the total ventilation rate, particularly in older, leaky, dwellings which can rely on infiltration to provide adequate indoor air quality. However, as explored in this paper, using a whole house airtightness metric to characterise ventilation rates can fail to identify low ventilation rates in specific rooms. 

The evaluation of real-time indoor environment parameters measured in 297 Chilean dwellings

People spend the majority of their time in their own homes and so the indoor environmental conditions are an important determinant of population health and wellbeing and have economic consequences. Chile is undergoing rapid economic growth and is managing its national energy demand to minimize its greenhouse gas emissions. Its housing stock is growing rapidly, and is responsible for 15% of national energy demand. Accordingly, there is a need to understand the performance of the stock by measuring parameters that indicate air quality, thermal comfort, and energy demand.

Trade-offs between ventilation rates and formaldehyde concentrations in new-build dwellings in the UK

The current policies and regulatory frameworks in the construction sector aim to improve energy efficiency of new buildings whilst maintaining acceptable level of indoor environmental quality (IEQ) including indoor air quality (IAQ). In practice, however, there are often important trade-offs between these objectives. The aim of this paper is to investigate the concentrations of volatile organic compounds (VOCs) in a recently built residential block in the UK and the potential trade-offs between ventilation rates and VOCs.

The effect of outdoor pollution and ventilation on Indoor Air Quality

The importance of reducing the ingress of outdoor pollution into the indoor environment is becoming increasingly important as concerns rise regarding the acute and chronic health effects of air pollution. In general, people in developed countries spend typically 90% or more of their time indoors, with the most susceptible individuals, such as the elderly and those with pre-existing medical conditions, spending almost all of their time indoors.

A comparison of line-sources of buoyancy placed near and far from a wall

Experiments are presented on turbulent buoyant free-line and wall plumes, whereby the buoyancy source is emitted from a horizontal line source, in one case free of the presence of a wall and in the other placed immediately adjacent to a wall. The dynamics of turbulent entrainment, whereby ambient fluid is mixed in to the plume, are explored. The velocity field and scalar edge of the plumes are measured. From this the time-averaged plume-width and volume flux are compared.

Determining the venting efficiency of simple chimneys for buoyant plumes

We present preliminary results from an examination of the capture and venting of a buoyant plume by a chimney. The aim is to enable improved management of indoor pollutant sources – for instance, the plume rising from a cooking pan in a kitchen or a cooking fire in a hut. Using the principle of dynamic similarity, we precisely and controllably model the behaviour of indoor plumes by using saline solutions ejected into an enclosure containing freshwater.

A Case Study assessing the impact of Shading Systems combined with Night-Time Ventilation strategies on Overheating within a Residential Property

Overheating in domestic homes, specifically in built up urban areas, has become a pressing problem throughout the UK. It is likely to become a costly energy problem in years to come if passive design strategies are not fully understood and integrated. This research looks to investigate how internal and external solar shading systems impact on operative temperatures when differing blinds together with a night time natural ventilation strategy are adopted within a renovated block of flats in North London.

Pages