English

Both critical and optimistic claims have been made regarding the performance of heat recovery ventilation systems (HRVS) in dwellings. Such arguments are raised partly because two key aspects are not fully clarified, i.e. the performance criteria and the influence of uncertainties. In the current paper, an assessment method for HRVS considering the influence of uncertainties is described. This includes  adequate assessment criteria, the method of identifying the uncertainties, and the method of addressing the influence of such uncertainties.

The control strategy for mechanical ventilation systems has significant impact on the performance of the system, in terms of energy consumption and correct air distribution. This paper presents a static pressure reset control system employing a new type of flow damper with lower pressure loss for use in low pressure ventilation systems. The flow damper has a droplet shape that minimizes turbulence generation and the resulting pressure loss. The performance of the damper was examined by making measurements of pressure loss and airflow.

In a world where energy conservation in buildings is an important target, natural ventilation is an important field in which carbon footprint reductions can be achieved. This paper investigates the possibility of creating horizontal channels to deliver natural cross ventilation passively in deep-plan buildings that otherwise would suffer from a lack of fresh air ventilation. The research objective has been to find a new system in which the depth of buildings is no longer an issue when it comes to natural ventilation.

Heating Ventilating and Air Conditioning (HVAC) systems are primarily designed for ensuring good indoor air quality and thermal comfort. However, building energy requirements tend to put demand on reducing air change rates. Passive control of jet flows in order to enhance mixing and entrainment may be a solution to this problem.

The approval of the Technical Building Code has meant major changes in the construction of multi-storey buildings in Spain. One of the most important revisions, with respect to the buildings erected prior to the Technical Building Code, has been the obligation to ventilate each one of its rooms. Depending on the use and occupancy a minimum flow rate of ventilation is required in each room.

The type and thickness of insulation on the topside horizontal of cold pitched roofs has a significant role in controlling air movement, energy conservation and moisture transfer reduction through the ceiling to the loft (roof void) space. To investigate its importance, a numerical model using a HAM software package on a Matlab platform with a Simulink simulation tool has been developed using insitu measurements of airflows from the dwelling space through the ceiling to the loft of three houses of different configurations and loft space. Considering typical UK roof underlay (i.e.

Natural ventilation in residential dwellings is very important for occupants’ health and comfort. Previous studies by the authors have concluded that natural ventilation performance in dwellings can be enhanced by positioning the two groups of window openings (bedroom windows and living room windows) in opposite directions or perpendicular to each other; and/or the use of side-hung windows. However, the buildings selected for those studies were located in an isolated site, for the purpose of focused evaluation of the influence of various configuration parameters and window types.

It is still difficult to confirm from available data if global warming and climate changes have played a role in increasing heat-related injuries. However, it is certain that global warming can increase the frequency and intensity of heat waves, which can cause discomfort to the human body and, in the worst case, can lead to more heat illness casualties. Recent worldwide natural disasters, such as the Tohoku earthquake in Japan, flooding in Thailand, and the Pakistan heat wave show that climate change is truly a fact.

Air tightness is an important property of building envelopes.  It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance.  Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ.  There are several methods for measuring air tightness that may result in different values and sometimes quite different uncertainties.

This paper reports on research carried out to develop natural ventilation control strategies for densely occupied learning spaces with the intention of improving indoor air quality and heating energy consumption. Investigations were carried out for two test cases according to the characteristics given in CIBSE Guide A (2006) and Building Bulletin (BB) 101 (UK Department for Education, 2006). The performance of these test cases were assessed using dynamic thermal simulation with fixed CO2 set-points, based on which opening dampers are controlled.