Local ventilation evaluation

Evaluation procedures for local ventilation are described in Section 10.5. The actual evaluation procedure for a specific system is mostly described in connection with the different parameters that influence the function of the system. Many of the evaluation procedures for general ventilation systems described in Chapter 12 could be used also for local ventilation. 

For supply inlets in rooms some performance measurements exist, such as air exchange and ventilation efficiencies (see Chapter 8). It is usually not possible to use these for local ventilation supply inlets, and for the moment there are no specific measurements to evaluate the influence of an inlet on contaminants. Some trials with comparison indices, which compare inhaled concentrations (or exposures) with and without a supply inlet, have been done. 

Different available measurement instruments and evaluation methods are described in Chapter 12. Some specific methods to evaluate local ventilation systems are described in this section. All local ventilation systems should be evaluated regularly. The evaluation procedures can be divided into detailed and simple, as well as direct and indirect, procedures. The detailed procedures need special instruments and competence, whereas it should be possible to use the simple procedures every day. Since the simple procedures do not measure directly the performance of the exhaust, it is usually necessary to calibrate a simple procedure by using a detailed procedure. ... 

Hoods. A laboratory hood with 2.5 linear feet of hood space per person should be provided for every 2 workers if they spend most of their time working with chemicals (199) each hood should have a continuous monitoring device to allow convenient confirmation of adequate hood performance before use (200, 209). If this is not possible, work with substances of unknown toxicity should be avoided (13) or other t)q)es of local ventilation devices should be provided (199). See pp. 201-206 for a discussion of hood design, construction, and evaluation. 

Evaluation. Quality and quantity of ventilation should be evaluated on installation (202), regularly monitored (at least every 3 months) (6, 12, 14, 195), and reevaluated whenever a change in local ventilation devices is made (12, 195, 207). Seepp. 195-198 for meth... 

Satsumoto, Y., Havenith, G. (2010). Evaluation of overall local ventilation in diapers. Textile Research Journal, 80(17), 1859—1871. 

Ventilation/ perfusion Vascular occlusion, presurgery evaluation <1 xm Pulmonary embolism, localized airway disease... 

Gressel MG (1997) An evaluation of a local exhaust ventilation control system for a foundry casting-cleaning operation. Am Ind Hygiene Assoc 58 254-258... 

The Local Technical Centre (LTC) evaluates the situation of the incident and the possible development that might be foreseen. The LTC is located near the control room. This centre has ventilation systems protected by aerosol and iodine filters. It is also equipped with emergency power supply and communication means are available for all communication channels necessary with redundant backup. There is an emergency communication system based on the INMARSAT satellite communication... 

In the semiconductor industry, local exhaust ventilation is a key control for the prevention of employee exposure to volatile chemicals. As such, exhaust ventilation measurement records are retained to allow the evaluation for trends in ventilation system performance and to provide exposure control information in the event of possible litigation. 

Most European centers supervise less than 50 patients. This limits the ventilator experience of the staff. But these small centers can provide the patient greater accessibility. The solution to the dilemma between accessibility and expertise is the creation of networks of centers. The centers with more expertise, technology, and specialists can give support to local centers with less technological resources but who are able to provide closer attention to the patient. Eventually the patient may be transferred from the local center to the center with more technological support for a more complex evaluation, but the routine care is given in the most accessible place. Moreover, in the context of a network the introduction of innovations is easier and permits a more homogeneous dissemination. 

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