scholarly journals Energy efficiency and indoor air quality of seminar rooms in older buildings with and without mechanical ventilation

Bauphysik ◽  
2019 ◽  
Vol 41 (5) ◽  
pp. 243-251
Author(s):  
Stefan Maas ◽  
Joël Da Cruz Antunes ◽  
Georges Steffgen
Keyword(s):  
Mechanical Ventilation ◽  
Energy Efficiency ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air

scholarly journals The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Aldona Skotnicka-Siepsiak
Keyword(s):  
Mechanical Ventilation ◽  
Energy Efficiency ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Residential Buildings ◽  
Coanda Effect ◽  
Air Jet ◽  
Coandǎ Effect ◽  
Ventilation Systems

Energy-saving ventilation systems are designed to improve the energy efficiency of buildings. Low energy efficiency in buildings poses a considerable problem that needs to be addressed. Mechanical ventilation with heat recovery has gained increased popularity in recent years. Mechanical ventilation has numerous advantages, including easy adjustment and control, high indoor air quality and elimination of indoor pollutants. Mixing ventilation is the most popular type of mechanical ventilation, in particular in residential buildings. Unsteady ventilation is a type of mixing ventilation that involves stronger mixing effects and smaller vertical temperature gradients to improve indoor air quality (IAQ) and minimize energy consumption. This study examines the possibility of controlling and modifying Coanda effect hysteresis (CEH) to generate unsteady flow and simulate the conditions of unsteady mixing ventilation. The experiment was performed on a self-designed test bench at the University of Warmia and Mazury in Olsztyn. It demonstrated that an auxiliary nozzle can be applied at the diffuser outlet to control CEH and the angles at which the air jet becomes attached to and separated from the flat plate positioned directly behind the nozzle. The study proposes an innovative mixing ventilation system that relies on CEH. The potential of the discussed concept has not been recognized or deployed in practice to date. This is the first study to confirm that an auxiliary nozzle by the diffuser outlet can be operated in both injection and suction mode to control CEH. In the future, the results can be used to design a new type of nozzles for unsteady ventilation systems that are based on CEH control.

scholarly journals Indoor air quality and control methods for mechanical ventilation systems inside large passive objects

2020 ◽  
pp. 1-8
Author(s):  
Nina Szczepanik-Ścisło
Keyword(s):  
Mechanical Ventilation ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Test Object ◽  
Control Methods ◽  
And Control ◽  
Sanitary Conditions ◽  
Ventilation Systems

This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants.

scholarly journals The Dichotomy between Indoor Air Quality and Energy Efficiency in Light of the Onset of the COVID-19 Pandemic

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 791
Author(s):  
Gaetano Settimo ◽  
Pasquale Avino
Keyword(s):  
Energy Efficiency ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Great Increase

Recently, there has been a great increase in the importance of issues related to energy efficiency [...]

The impact of mechanical ventilation operation strategies on indoor CO2 concentration and air exchange rates in residential buildings

2020 ◽  
pp. 1420326X2096076
Author(s):  
Pedro F. Pereira ◽  
Nuno M. M. Ramos
Keyword(s):  
Mechanical Ventilation ◽  
Air Quality ◽  
Exchange Rates ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Residential Buildings ◽  
Ventilation Strategy ◽  
The Impact ◽  
Mechanical Extraction ◽  
Air Exchange

In Portugal, residential buildings commonly have their ventilation strategy changed after commissioning. This occurs due to the building managers' willingness to reduce shared costs with the electricity needed for fan operation. However, this option is not technically supported, and the effects of such a strategy on indoor air quality-related to human pollutants are yet to be quantified. CO2 was monitored in 15 bedrooms and air exchange rates were calculated for each room. The air exchange rate values ranged from 0.18 to 0.53 h−1 when mechanical extraction ventilation was off, and from 0.45 to 0.90 h−1 when mechanical extraction ventilation was on, which represents an average increase of 119%. With the current intermittent ventilation strategy, all rooms remain above 1500 ppm for a given percentage of time, and 12 rooms presenting CO2 concentrations above 2000 ppm. Simulations of theoretical CO2 concentrations, for a non-interrupted mechanical ventilation strategy show that no rooms would accumulate CO2 concentrations above 2000 ppm, and only 25% would present CO2 concentrations above 1500 ppm. Pearson correlations between the monitored CO2 and human and spatial factors identified two relevant parameters. Those parameters correspond to ratios between CO2 generation and floor area ([Formula: see text]), and airflow with CO2 generation ([Formula: see text]). The proposed ratios could be used as ways to optimise ventilation costs and indoor air quality.

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