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Demand Controlled Ventilation
Demand controlled ventilation (DCV) is a feedback control method to maintain indoor air quality that automatically adjusts the ventilation rate provided to a space in response to changes in conditions such as occupant number or indoor pollutant concentration Measures of pollutant concentration are used to determine Risk assessment#Risk assessment in public health, risk assessment in public health. Secondary sector of the economy, Industry is continually Chemical synthesis, synthesizing new chemicals, t .... The control strategy is mainly intended to reduce the energy use by heating, cooling, and ventilation systems compared to buildings that use open-loop controls with constant ventilation rates. Common reference standards for ventilation: * ISO ICS 91.140.30: Ventilation and air-conditioning systems * ASHRAE 62.1 & 62.2: The standards for Ventilation and Indoor Air Quality Examples of estimating occupancy * Timed schedules * Motion sensors (various technologies including: Aud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Theory
Control theory is a field of mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a desired state, while minimizing any ''delay'', ''overshoot'', or ''steady-state error'' and ensuring a level of control stability; often with the aim to achieve a degree of optimality. To do this, a controller with the requisite corrective behavior is required. This controller monitors the controlled process variable (PV), and compares it with the reference or set point (SP). The difference between actual and desired value of the process variable, called the ''error'' signal, or SP-PV error, is applied as feedback to generate a control action to bring the controlled process variable to the same value as the set point. Other aspects which are also studied are controllability and observability. Control theory is used in control system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measures Of Pollutant Concentration
Measures of pollutant concentration are used to determine risk assessment in public health. Industry is continually synthesizing new chemicals, the regulation of which requires evaluation of the potential danger for human health and the environment. Risk assessment is nowadays considered essential for making these decisions on a scientifically sound basis. Measures or defined limits include: * ''no-observed-adverse-effect level'' (NOAEL), also called ''no-effect concentration'' (NEC), ''no-observed-effect concentration'' (NOEC) or similarly * '' lowest-observed-adverse-effect level'' (LOAEL) * ''acceptable operator exposure level'' (AOEL) * ECx (in percentage). No-effect concentration ''No-effect concentration'' (NEC) is a risk assessment parameter that represents the concentration of a pollutant that will not harm the species involved, with respect to the effect that is studied. It is often the starting point for environmental policy. There is not much debate on the existence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
