Data-Driven Models for Estimating Dust Loading Levels of ERV HEPA Filters

With increasing global concerns regarding indoor air quality (IAQ) and air pollution, concerns about regularly replacing ventilation devices, particularly high-efficiency particulate air (HEPA) filters, have increased. However, users cannot easily determine when to replace filters. This paper proposes models to estimate the dust loading levels of HEPA filters for an energy-recovery ventilation system that performs air purification. The models utilize filter pressure drops, the revolutions per minute (RPM) of supply fans, and rated airflow modes as variables for regression equations. The obtained results demonstrated that the filter dust loading level could be estimated once the filter pressure drops and RPM, and voltage for the rated airflow were input in the models, with a root mean square error of 5.1–12.9%. Despite current methods using fewer experimental datasets than the proposed models, our findings indicate that these models could be efficiently used in the development of filter replacement alarms to help users decide when to replace their filters.

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Energetic investigation of energy recovery technologies in air handling units

International Review of Applied Sciences and Engineering ◽

10.1556/1848.2018.9.1.7 ◽

2018 ◽

Vol 9 (1) ◽

pp. 49-57

Author(s):

L. F. Al-Hyari ◽

M. Kassai

Keyword(s):

Energy Consumption ◽

Indoor Air ◽

Energy Recovery ◽

Ventilation System ◽

Ambient Air ◽

Existing Buildings ◽

Exact Methods ◽

Technical Data ◽

Air Temperatures ◽

Air Handling Units

The statistical data show that the application of active cooling is spread widely in residential and commercial buildings. In these buildings, the ventilation is significantly increased in the whole energy consumption. There are similar problems in the operation of post-insulation of existing buildings. In this case, the energy consumption of the ventilation system gives a major proportion of the whole building services energy consumption. The opportuneness of this research shows that the actual available calculation procedures and technical designing data are only rough approximations for analyzing the energy consumption of air handling units and the energy saved by the integrated heat or energy recovery units. There are not exact methods and unequivocal technical data. In previous researches, the production and development companies have not investigated the effectiveness of the energy recovery units under difference ambient air conditions and the period of defrost cycle when the heat recovery can only partly operate under difference ambient air temperatures. During this term, a re-heater has to fully heat up the ambient cold air to the temperature of supplied air and generate the required heating demand to provide the necessary indoor air temperature.

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Research on Best Solution for Improving Indoor Air Quality and Reducing Energy Consumption in a High-Risk Radon Dwelling from Romania

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182312482 ◽

2021 ◽

Vol 18 (23) ◽

pp. 12482

Author(s):

Ion-Costinel Mareș ◽

Tiberiu Catalina ◽

Marian-Andrei Istrate ◽

Alexandra Cucoș ◽

Tiberius Dicu ◽

...

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Heat Recovery ◽

Natural Ventilation ◽

High Efficiency ◽

Ventilation System ◽

Radon Level

The purpose of this article is the assessment of energy efficiency and indoor air quality for a single-family house located in Cluj-Napoca County, Romania. The studied house is meant to be an energy-efficient building with thermal insulation, low U-value windows, and a high efficiency boiler. Increasing the energy efficiency of the house leads to lower indoor air quality, due to lack of natural ventilation. As the experimental campaign regarding indoor air quality revealed, there is a need to find a balance between energy consumption and the quality of the indoor air. To achieve superior indoor air quality, the proposed mitigation systems (decentralized mechanical ventilation with heat recovery combined with a minimally invasive active sub-slab depressurization) have been installed to reduce the high radon level in the dwelling, achieving an energy reduction loss of up to 86%, compared to the traditional natural ventilation of the house. The sub-slab depressurization system was installed in the room with the highest radon level, while the local ventilation system with heat recovery has been installed in the exterior walls of the house. The results have shown significant improvement in the level of radon decreasing the average concentration from 425 to 70 Bq/m 3, respectively the carbon dioxide average of the measurements being around 760 ppm. The thermal comfort improves significantly also, by stabilizing the indoor temperature at 21 °C, without any important fluctuations. The installation of this system has led to higher indoor air quality, with low energy costs and significant energy savings compared to conventional ventilation (by opening windows).

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Solid Oxygen-Purifying (SOP) Filters: A Self-Disinfecting Filters to Inactivate Aerosolized Viruses

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17217858 ◽

2020 ◽

Vol 17 (21) ◽

pp. 7858

Author(s):

Michael Versoza ◽

Jaeseok Heo ◽

Sangwon Ko ◽

Minjeong Kim ◽

Duckshin Park

Keyword(s):

Viral Load ◽

Indoor Air ◽

Air Conditioning ◽

Pathogenic Bacteria ◽

High Efficiency ◽

Hvac Systems ◽

Virus Particles ◽

Solid Oxygen ◽

Filter Dust ◽

Model Virus

Normal heating, ventilation, and air conditioning (HVAC) systems typically use high-efficiency particulate air (HEPA) filters, which can filter dust, various pollutants, and even bacteria and viruses from indoor air. However, since HEPA filters cannot not clean themselves and due to the nature of these microbes which can survive for long periods of time, changing these filters improperly could transmit pathogenic bacteria or viruses, and could even lead to new infections. This study indicated that these manufactured Solid Oxygen-purifying (SOP) filters have the potential to self-disinfect, filter, and inactivate aerosolized viruses. MS2 bacteriophage was used as a model virus in two different experiments. The first experiment involved aerosolization of the virus, while the second were a higher viral load using a soaking method. The SOP filters inactivated up to 99.8% of the virus particles in both experiments, provided that the density of the SOP filter was high. Thus, SOP filters could self-clean, which led to protection against airborne and aerosolized viruses by inactivating them on contact. Furthermore, SOP filters could be potentially use or addition in HVAC systems and face masks to prevent the transmission of airborne and aerosolized viruses.

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Room-temperature oxidation of gaseous HCHO over metal molybdate nanorods with Pt as co-catalysts

Functional Materials Letters ◽

10.1142/s1793604715500794 ◽

2015 ◽

Vol 08 (06) ◽

pp. 1550079 ◽

Cited By ~ 2

Author(s):

Gang Zuo ◽

Haibin Chen ◽

Yu Yang ◽

Bowen Zhou ◽

Han Xiao ◽

...

Keyword(s):

Indoor Air ◽

Room Temperature ◽

High Efficiency ◽

Air Purification ◽

Temperature Oxidation ◽

Co Catalysts ◽

Potential Applications ◽

Efficiency Cost ◽

Environmentally Sound ◽

Indoor Air Purification

High-efficiency, cost-affordable and environmentally sound catalysts are urgently needed for indoor air purification. Herein, we report the first investigation on room-temperature removal capabilities of AMoO 4 ( A = Ni and Co ) and derived molybdate– Pt composites with uniform nanorod morphology. The HCHO removal or oxidation capabilities and mechanisms are also compared and rationalized, which, we hope, can form a solid basis for potential applications of molybdate for indoor air purification.

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Effect of Air Purification Systems on Particulate Matter and Airborne Bacteria in Public Buses

Atmosphere ◽

10.3390/atmos13010055 ◽

2021 ◽

Vol 13 (1) ◽

pp. 55

Author(s):

Jae Jung Lee ◽

Hyemin Hwang ◽

Suk Chan Hong ◽

Jae Young Lee

Keyword(s):

Particulate Matter ◽

Air Quality ◽

South Korea ◽

Indoor Air Quality ◽

Indoor Air ◽

High Efficiency ◽

Transport Systems ◽

Air Purification ◽

Airborne Bacteria ◽

Pm2.5 And Pm10

The indoor air quality in public transport systems is a major concern in South Korea. Within this context, we investigated the effect of air purification systems on the indoor air quality of intercity buses, one of the most popular transport options in South Korea. Air purifiers were custom designed and equipped with high-efficiency particulate air (HEPA) filters to remove particulate matter and ultraviolet light-emitting diodes (UV-LEDs) to remove airborne bacteria. To investigate the effectiveness of the air purification systems, we compared concentrations of particulate matter (PM2.5 and PM10), airborne bacteria, and carbon dioxide (CO2) in six buses (three with air purification systems and three without) along three bus routes (BUS1, BUS2, BUS3) in Gyeonggi Province, South Korea, between 6 April and 4 May 2021. Compared to the buses without air purification, those with air purification systems showed 34–60% and 25–61% lower average concentrations of PM2.5 and PM10, respectively. In addition, buses with air purification systems had 24–78% lower average airborne bacteria concentrations compared to those without air purification systems (when measured after 30 min of initial purification).

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Experimental investigation of carbon dioxide cross-contamination in sorption energy recovery wheel in ventilation system

Building Services Engineering Research and Technology ◽

10.1177/0143624417744733 ◽

2017 ◽

Vol 39 (4) ◽

pp. 463-474 ◽

Cited By ~ 12

Author(s):

Miklos Kassai

Keyword(s):

Carbon Dioxide ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Energy Recovery ◽

Ventilation System ◽

Test Facility ◽

High Humidity ◽

Cross Contamination ◽

Heat And Moisture

The aim of this research was to investigate the scale of carbon dioxide recirculation in rotary energy wheel operated in air handling units. To achieve this objective, a test facility was installed into the indoor air quality and thermal comfort laboratory of BUTE University. A newly developed molecular 3 Å sieve sorption wheel with high humidity transfer efficiencies is integrated into the experimental setup. In this research study, carbon dioxide cross-contamination rate from the exhaust side into the supply side in sorption regenerative air-to-air rotary energy exchanger was conducted by experimental tests. During the study, the correlation between the carbon dioxide cross-contamination, different rotational speeds of the wheel and different volume flow rates of supply air were also investigated in detail. Based on the results, a rotation speed diagram – carbon dioxide cross-contamination diagram – is plotted which can be very useful for researchers, developers and building service engineers in practice. Practical application: The most perfect energy exchanger can transfer both heat and moisture, thus providing a pleasant indoor air quality in the conditioned space. It is beneficial if the exchanger can transfer heat and moisture between the supply and exhaust airstreams, thereby minimizing the capacity and energy consumption of the required auxiliary heater and humidifier. The auxiliary energy reduction can be especially high if the sorption material of the energy wheel is of type 3 Å molecular sieve that has an extremely high humidity transfer capacity. The disadvantage of the rotary energy recovery is the cross-contamination from the exhaust air to the supply air. This is very important because in places such as offices, schools, public institutions, carbon dioxide cross-contamination can cause degradation of indoor air quality.

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