energy

Room pressure differential is an important aspect in order to guarantee sufficient contamination control, but is difficult to control in airtight cleanrooms. This research uses simulation models to get an understanding and to quantify the room pressure controllability of airtight cleanrooms. The most influential parameters on the room pressure controllability are identified using a sensitivity analysis. The effects of the shell airtightness and overflow flowrates are quantified, and the effect of a flow/pressure cascade with three coupled rooms is investigated.

This paper presents the initial reflections in the frame of Subtask 1 – Setting the Metrics of the IEA EBC Annex 68 – Indoor Air Quality Design and Control in Low Energy Residential Buildings. The first step of IEA Annex 68 aims at summarizing the current knowledge on target pollutants for residential buildings and at evaluating indoor air quality (IAQ), i.e. how to define indices that provide useful information allowing to achieve low risks for health in indoor spaces, and how to enable the comparison of solutions for achieving high IAQ taking into account energy efficiency.

In many post-occupancy studies of renovated houses elevated temperatures have been documented. This article presents in which situations overheating need to be addressed and which renovation measures are causing this need. The analysis contains representative houses from central and north Europe. Both dynamic and static overheating assessment criteria are used.

The modelling of air flows to investigate indoor air quality and energy issues has been a topic at the AIVC for all of its 40 years. Models have been developed that range in complexity from single-zone algebraic expressions that can be calculated by hand to complex multi-zone approaches that integrate contaminant transport and other functions.

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.

In 2017 the Danish Building and Property Agency started a project titled “Avoiding energy waste in ventilation systems” by tracking the actual energy use in a sample of their 4 million m2 portfolio of buildings through on-line energy management tools. The project is not complete, but the key preliminary findings  described in this paper are: 

Energy use in buildings has a significant influence on the global energy demand and environmental impacts. Among all building systems, heating, ventilation, and air conditioning (HVAC) systems are the most energy-intensive in terms of their total energy requirements. The production and operation of HVAC systems have a significant impact on the environment. These systems are also among the largest consumers of natural resources and materials in the building sector.

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.

Mechanical ventilation is vital in modern homes to insure adequate indoor air quality. However, builders, homeowners and policy makers may perceive best practice as a risk, especially if invoked during peak outdoor thermal conditions which may compromise comfort and energy use. In North America, ASHRAE Standard 62.2- 2016 defines best practice, yet ventilation code specifications vary internationally.