Evolution of ventilation strategies in air-conditioned buildings in Singapore – IAQ and Energy perspectives

Situated 1º North of the equator, Singapore has a year-round hot and humid climate with temperatures in the range of 25 and 32º C and relative humidity around 70%.  In view of these environmental conditions, there is really no need for “Heating (or simply “H”) in the traditional Heating, Ventilating and Air-Conditioning (HVAC) terminology.  Consequently, the term Air-Conditioning and Mechanical Ventilation (ACMV) is used in the local industry.

Minimising the influence of the stack effect and wind on the operation of mechanical exhaust ventilation systems

Ventilation systems play an important role in providing a good indoor air quality in dwellings. Mechanical exhaust ventilation systems implement natural vents, also called trickle vents, to supply outdoor air to the dwelling. The airflow through these natural supply vents depends on the natural driving forces, i.e. wind and the stack effect, which vary in time.  

Performances of a demand-controlled mechanical supply ventilation system under real conditions: indoor air quality and power distribution for thermal comfort

This study aims to evaluate the performances of a VMI, a demand-controlled mechanical supply ventilation system, in an experimental house, in terms of indoor air quality (IAQ), energy performance and thermal comfort. The positive input ventilation draws fresh air from the outside, filters and preheats or precools it before blowing it every dry rooms. The air circulates through doors’ undercuts and is naturally extracted thanks to exhaust orifices in every wet rooms. A heat exchanger supplied with water from a reversible heat pump is used to preheat or precool the blown air.

Indoor air quality in Nearly Zero Energy Buildings, reduction of exposure

Various studies show a deterioration in indoor air quality after renovation and energy saving measures. NZEB dwellings are at the moment at an airtightness level, that the old slogan make buildings airtight and ventilate right is an very import solution for a good IAQ, but not without source control. 

Thermal comfort, IAQ and Energy use in Bedrooms

The research question of this report is “Is it possible to save energy by lowering the bedroom temperatures in winter”. In this paper first the literature on optimum sleeping temperatures is investigated. Then bedroom temperatures and CO2 levels in a cold week in March 2018 are investigated in 16 bedrooms of students of the Master course Technoledge Climate Desing in 2017-2018 of the faculty of Architecture and the Built Environment of the Delft University of Technology. This study shows that it must be possible to save energy by lowering the bedroom temperature in winter.

Residential balanced ventilation and its tested impacts on indoor pressure and air quality

This paper presents results from a project on the assessment of the indoor air quality (IAQ) benefits that might accrue from the use of a balanced energy recovery ventilation system. The study compared the whole-building pressure, IAQ and ventilation performance of a balanced energy recovery ventilation (ERV) system with that of an exhaust-only ventilation system (continuous exhaust from master bathroom).

Are low-cost sensors good enough for IAQ controls?

Over the past few years there have been advances in sensing of some pollutants, primarily particles, that might lead to ventilation controls based on direct sensing of pollutants – particularly those relating to health. In this study we evaluated low-cost (about $200 US) IAQ monitors that measured PM2.5 - the most important health-related pollutant in indoor air. Controlled laboratory tests were carried out with known sources of particles (cooking, cleaning, candles, cigarettes) and by comparing the IAQ monitors response to research-grade and reference measurement methods.

Use of low cost IAQ sensors?

The difficulty in measuring IAQ indicators like VOCs and particles, lies in the multiplicity of the composition of these pollutants. Analysis of the responses of some low cost IAQ sensors when subjected to real sources of pollution shows that they do not react homogeneously, due to their sensitivity and post-treatments. These sensors can be used by consumers to understand the effect of their actions on the evolution of IAQ indicators, not to rely directly on the values displayed.

Smart monitoring of ventilation system performance with IEQ sensor networks

The recent development of affordable and quite accurate temperature sensors and Indoor Air Quality (IAQ) sensors has led to a growing interest in continuous indoor climate monitoring. Not just amongst scientists and engineers but also amongst building owners, developers and e.g. architects interested in boosting our buildings’ health and comfort qualities.

Assessing the energy use and IAQ of various HVAC systems during the early design stage

The early design stage of a building is decisive for describing the concept of the HVAC system. Designers and practitioners can adjust and optimize the design during this stage as it provides them with enough resilience to adapt new changes. In practice, a well-defined optimization process is essentially required in order to achieve the project’s goals within a reasonable time span. These goals vary from one project to another, and sometimes they require a comprehensive study to identify the factual and stochastic parameters and their impact on the design.

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