United Kingdom

Demand controlled ventilation (DCV) can improve the energy performance of all kinds of ventilation systems, in residential and non-residential buildings and is already part of the European Lot 6 and Ecodesign regulations and standards. However, the lack of recognition of DCV in SAP (Standard Assessment Procedure) forms a great barrier for the use of this technology in the UK. A methodology was developed to prove the guarantee on good IAQ, with potential saving on heating and auxiliary energy by modulating ventilation rates based on actual demand.

Noise from domestic ventilation systems is currently a little understood problem in the UK. Other European countries that have a longer history of using mechanical domestic ventilation systems have introduced noise limits for these systems. Without mandatory limits for noise in UK, noise is not a factor that is often considered during the design. However, noise can be a significant constraint to the use of ventilation systems. Research is reviewed from across Europe and North America that indicates residents turn off ventilation equipment with objectionable noise.

Where residential developments rely on opening windows to control overheating, there can be a compromise between allowing excessive noise ingress with windows open, or excessive temperatures with windows closed. This problem is exacerbated by the move towards better insulated, more airtight buildings and the need, particularly in urban areas, to consider development on noisier sites. A working group has been formed by the Association of Noise Consultants to provide guidance on acoustic conditions and design when considering both the provision of ventilation and prevention of overheating.

Urban warming, commonly referred to as the ‘Urban Heat Island’ phenomenon (UHI), is a well-established effect that affects cities all over the world. This occurs due to urban physical characteristics such as urban canyon geometry and vegetation, but mainly to its typical materials. The thermal properties of the materials used for the external walls and roofs of buildings, as well as pavements, can have a major influence on the surface temperature. As a consequence of increased temperature, the UHI has an effect on energy consumption for heating and cooling urban buildings.

Exposures to airborne fine particulate matter with a diameter of <2.5μm (PM2.5) are linked to multiple negative health effects, including cardiovascular and respiratory disease. Existing investigations of PM2.5 primarily focus on external sources and exposures, because outdoor air is easier to observe, and therefore, more widely monitored. However, as people spend up to 70% of their time in their own homes, exposures to indoor pollutants could have a greater impact on health. One method of investigating indoor exposures in a stock of houses is by modelling them.

CFD simulations were conducted to assess turbulent forced convection heat transfer and pressure drop through a ventilation channel using a stack of panels with different ridge configurations containing Phase Change Material (PCM). First, an experimental rig using an existing commercial panel provided by a PCM manufacturer validates the model simulated in Ansys FLUENT. After that, 3D simulations with different designs were tested until the optimum configuration in terms of heat transfer and pressure drop was achieved.

Night ventilation is used extensively as a low energy strategy to cool buildings in climates where night temperatures are suitable. It can be used for spaces utilising natural or mechanical ventilation systems as well as active refrigerant cooling. Most published work focuses on domestic and relatively simple in operation commercial buildings such as offices. This paper presents a study of the cooling benefits of night ventilation for frozen food supermarkets with high cooling demand.

There are three common methods used to analyse Indoor Air Quality in buildings: in-site measurements, laboratory measurements, or the simulation of indoor spaces using a validated computational model. Each have their advantages, but computational models are generally used to predict air quality in a wide range of indoor environments because they are quick, cheap, and non-invasive. A wide range of inputs are required to accurately simulate airflow and pollutant transport. However, this information may not exist or may only exist in abstract forms.

A literature review has revealed that there is a very limited number of numerical or experimental studies of the air flow for mechanically ventilated large occupied rooms. Existing literature suggests that a room with more than 5 meters floor-to-ceiling height can be considered as a large space. The aim of this paper is to present a set of detailed air temperature and velocity measurements in a large open plan office located in south England.

One of the key objectives of the IEA Annex 68 research programme entitled “Indoor Air Quality Design and Control in Low Energy Residential Buildings” is to provide a generic guideline for the design and operation of ventilation in residential buildings. They need to have minimal energy consumption, and at the same time maintain a high level of Indoor Air Quality (IAQ). The paper reports on preliminary results of an interview survey conducted among different stakeholders involved in design, installation and operation of residential ventilation in countries involved in the Annex.