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.

Isolation Rooms - CFD Simulations of Airborne Contamination Through Doors During Passage

There has been an increase in diseases caused by airborne infections such as influenza A/H1N1 or SARS in the recent years. Airborne infection isolation rooms are commonly used to limit the spread of airborne infections. The challenge today is that there is only a limited number of airborne infection isolation rooms in each hospital (class P4). The rooms are expensive to build and airflow control to avoid contamination is often complicated.

Case study : comparison between a central and a decentral ventilation unit in a school building from the 80’s

Ventilation and healthy classes are a recurring problem. Continuously increasing the air flow rate improves the living environment, but is unacceptable in terms of higher costs and energy loss, which is why a different approach is needed. The research question asked in this study is : Is a central ventilation system operating at low power, but combined with a decentralised ventilation system with heat recovery, more economical and energy efficient and at the same time does it provide the premises with a constant and good air quality?

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).

Influence of multizone airleakage on IAQ performance in residential buildings

This article proposes to study the impact of envelope and internal partition walls airleakage distributions, on the indoor air quality (IAQ) performance. It is based on a preliminary performance-based approach using formaldehyde with three emission levels (low, medium, high). This multizone modelling (CONTAM) approach uses as performance indicators, the average concentration per room as well as the percentage of time of exceeding the limit value (ELV) of 9 µg.m-3.

A holistic evaluation method for decentralized ventilation systems

The implementation of decentralised ventilation units is growing, especially in the residential retrofit. These systems are typically simple to install on site (usually in the external façade with no additional ductwork) and allow room-by-room control strategies. Until now, decentralised systems are evaluated by applying the same methodologies as for centralised ventilation systems, even though different boundary conditions apply. Some differences are for example:  

An experimental investigation into the ventilation effectiveness of diffuse ceiling ventilation

Diffuse ceiling ventilation is a novel air distribution concept, where the space above a suspended ceiling is used as a plenum and fresh air is supplied into the occupied zone through perforations in the suspended ceiling panels. Due to the low momentum supply, the airflow in the room is driven by buoyancy force generated by heat sources. The previous studies indicate that the diffuse ceiling ventilation system can effectively eliminate the draught risk in the occupied zone and provide a comfortable indoor environment even with low-temperature supply.

Experimental study on the measurement of Building Infiltration and Air Leakage rates (at 4 and 50 Pa) by means of Tracer Gas methods, Blower Door and the novel Pulse technique in a Detached UK Home

Air infiltration contributes to a heat loss typically representing up to one third of the heating demand of a building. The building airtightness, also quantified as air leakage, is the fundamental building property that impacts infiltration. The steady (de)pressurization method (blower door) is the widely accepted standard process for measuring building air leakage. However, this method requires the enclosure to be pressurised to a typical range of 10-60 Pa, which is not physically representative of the pressures experienced by buildings under natural conditions.

Comparison of experimental methodologies to estimate the air infiltration rate in a residential case study for calibration purposes

The air renovation of a building should be controlled in order to ensure a proper level of indoor air quality while minimize heat losses. It is a crucial point for the future energy efficiency goals. However, air infiltration rate in buildings is a complex parameter which is influenced by several boundary conditions. Although a detailed dynamic analysis could be used to properly characterize the phenomenon, estimated values can be obtained from experimental methods, as Blower Door test and gas concentration-based approaches.

A new method to measure building airtightness

In this paper a new methodology is presented to determine airtightness of buildings. The common method for airtightness testing is through fan pressurization with a blower door test. The new methodology also uses fan pressurization. Instead of an external fan, it uses the building fan system to pressurize the building.  

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