Through ventilation

Through ventilation Ventilation that takes place through a space due to wind forces, normally resulting in poor mixing of the room air due to short circuiting. 

In a cosmetic laboratory, a recirculating system would have been adequate except for one very special condition. The noses had to perform their fragrance evaluations in a clean atmosphere. This called for once-through ventilation and included placing drying ovens under a simple hood extending part way down from the ceiling. The result was excellent. 

Other Recirculation or exhaust air from chemical areas is prohibited. No connection between chemical areas and other areas through ventilation system is permitted. Emergency backup power is necessary. Hoods should be tested at least semiannually or after modification or maintenance operations. Operations should be performed 20 centimeters inside hood face. 

OTHER Recirculation of exhaust air from agent areas is prohibited. No connection is allowed between agent areas and other areas through ventilation system. 

Restrooms, laboratories, and uninterruptible power supply (UPS) systems and battery rooms should have once through ventilation. Laboratories and battery rooms should only be accessed from the outside. 

They are normal compounds of the external atmosphere, which get into the interior by exchange with the outside air through ventilation, bricking joints or leaky windows. 

So, hydrogen (with m = 2 10 3kg) diffuses in an easy way through ventilation openings, compared with heavy gases like oxygen (m = 32 10 kg) or carbon dioxide (m = 44 10 3kg). 

The number (n) of aerosol droplets floating in the air decreases with time because of loss through ventilation and adherence to materials in the room. The rate of change of n is given by the following ... 

You must test all levels of air in the confined space, because all gases and vapors are different and find their own level in the air. If testing reveals that the air is rmsafe, you must deal with the hazardous atmosphere through ventilation or respiratory protection. 

In Dhauliganaga Project (Uttarakhand, India) of NHPC, during construction of headrace tunnel in the intermediate adit portion, the working condition became extremely difficult due to increase of temperature of the tunnel up to 42°C. It was very difficult to even stand inside the tunnel for a longer duration. To improve the ergonomics of the crew members inside the tunnel, ice plant was installed and cooled compressed air was blown inside the tunnel through ventilation duct in order... 

Activity release into the atmosphere through ventilation is conditioned by a primary circuit gas leak and activation of reactor cavity cooling air. During normal plant operation, the gas activity released into the atmosphere does not exceed 2.5x10 Bq/day, which is much less than the allowable level of 1.9x10 Bq/day [XVI-6]. 

The health physics and hot machine shop HVAC system is a once-through ventilation s> stem consisting of two integrated subsystems a supply air system and an exhaust air system. The systems operate in conjunction with each other to satisfy the functional requirements of maintaining temperatures in the areas served while controlling air flow paths and area negative... 

The major route of uptake for PAHs has been debated for years. For the more water-soluble PAHs, it is believed that the main route of uptake is through ventilated water and that the more hydrophobic compounds are taken in mainly through ingestion of food or sediment. There are many variables, such as chemical hydrophobicity, uptake efficiency, feeding rate, and ventilatory volume, which may affect the outcome. The route of uptake may be an important issue for short-term events however, under long-term exposure and equilibrium conditions between water, prey, and sediment, the route of uptake may be immaterial because the same tissue burdens will be achieved regardless of uptake routes. The key assumption of equilibrium between these different compartments may, however, rarely occur for PAHs. 

Coal miners experience hazards from viewpoint inside of the spaces they describe. Agencies and management view these same experiences from a viewpoint outside of and above the same environment. Miners pass through ventilation curtains and move inside of haulageways that appear as subtle markings on a two-dimensional map of the ventilation system. 

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