Energy Efficiency Of Ventilation Research Articles

Smart energy management of combined ventilation systems in a nZEB

The high energy consumption, attached to a high energy demand in buildings, has led the development of several research projects with the target of reducing the energy consumption in the buildings. As a result of this high consumption, the increased CO2 emissions that have been generated in recent years, have reached alarming levels, which is why it is necessary to reduce the environmental impact which we are contributing to our planet through the use of energy. The European Directive on Building Performance (EPBD 2018/844/EU), recently updated, requires new buildings to be close to the Zero Energy Buildings (nZEBs), increasing the use of renewable energies on-site, and also highlight how to get to improve the cost-effective renovation of existing buildings with the introduction of building control and automation systems ( smart systems), as well as the energy savings and increase the efficiency of energy systems, by reducing CO2 emissions. The use of new renewable energy technologies integrated in buildings, with the aim of reducing the consumption of the facilities that all nZEB buildings must have, such as the ventilation system used as an Indoor Air Quality (IAQ) control technique. In this study, the energy management of the enthalpy ventilation control system is analysed, where dynamic monitoring is going on in the building controlled through Supervisory Control And Data Acquisition (SCADA), in combination with different ventilation systems as free-cooling, heat recovery and geothermal energy of an Earth Air Heat eXchanger (EAHX), all of them as strategies implemented in a real nZEB building (LUCIA) located on the campus at the University of Valladolid, with the goal of improving energy efficiency in ventilation. In order to get this aims, monitoring data of several energy parameters (temperature, air velocity, air flow rate, enthalpy, etc.) are measurements, they allow us to perform a control of the combined ventilation systems to achieve a high IAQ and analyze an optimization of the energy efficiency of the all systems and to study of energy recovery and savings of carbon emissions that directly affect the reduction of the impact of climate change. The results achieved are the energy efficiency of the building in ventilation and optimum system operation in cooling and heating mode. In addition, by controlling the ventilation, the IAQ of the nZEB building is improved.

Обеспечение безопасности и энергоэффективности при проветривании шахт и рудников, использующих систему рециркуляции воздуха

Обеспечение безопасности и энергоэффективности при проветривании шахт и рудников, использующих систему рециркуляции воздуха

Ventilation rates in large commercial layer hen houses with two-year continuous monitoring

1. Ventilation controls the indoor environment and is critical for poultry production and welfare. Ventilation is also crucial for assessing aerial pollutant emissions from the poultry industry. Published ventilation data for commercial layer houses have been limited, and are mostly based on short-term studies, mainly because monitoring airflow from large numbers of fans is technically challenging. 2. A two-year continuous ventilation monitoring trial was conducted at two commercial manure belt houses (A and B), each with 250 000 layers and 88 130-cm exhaust fans. All the fans were individually monitored with fan rotational speed sensors or vibration sensors. Differential static pressures across the house walls were also measured. Three fan performance assessment methods were applied periodically to determine fan degradations. Fan models were developed to calculate house ventilations. 3. A total of 693 and 678 complete data days, each containing >16 h of valid ventilation data, were obtained in houses A and B, respectively. The two-year mean ventilation rates of houses A and B were 2·08 and 2·10 m3 h−1 hen−1, corresponding to static pressures of −36·5 and −48·9 Pa, respectively. For monthly mean ventilation, the maximum rates were 4·87 and 5·01 m3 h−1 hen−1 in July 2008, and the minimum were 0·59 and 0·81 m3 h−1 hen−1 in February 2008, for houses A and B, respectively. 4. The two-year mean ventilation rates were similar to those from a survey in Germany and a 6-month study in Indiana, USA, but were much lower than the 8·4 and 6·2 m3 h−1 hen−1 from a study in Italy. The minimum monthly mean ventilation rates were similar to the data obtained in winter in Canada, but were lower than the minimum ventilation suggested in the literature. The lower static pressure in house B required more ventilation energy input. The two houses, although identical, demonstrated differences in indoor environment controls that represented potential to increase ventilation energy efficiency, and reduce carbon footprints and operational costs.