1.3.1.4 Introduction A common type of heat exchanger used in industrial ventilation is the plate fin-and-tube heat exchanger (Fig. 9.7). Liquid or gas flows in the Tubes, with a gas or a liquid circulating outside the tubes between the Plates. The plates can be straight or wavy. Wavy plates, due to their greater sur­face area, […]

1.3.1.1 Introduction A heat exchanger is a device that transfers heat from one medium to an­other; the medium may be a solid, liquid, or gas. Some of the most complex engineering design problems relate to heat exchangers. Heat exchangers are divided into the following types. 1. Recuperator: A wall separating the flowing fluids is the […]

The following points should be borne in mind when planning filter installa­tions. • Great care is required regarding the positioning and design of the air intake to avoid drawing in local impurities and rain or snow. • The risk of microbial growth is low, but to minimize the risk, the plant should be designed so […]

9.2.5.1 Environment: Life-Cycle Analysis (LCA) Global environmental questions have increased in significance during the last few years. A life-cycle analysis (LCA) analyzes the environmental ef­fect with reference to ecological effects, health effects, and consumption of resources. Life-cycle analysis of a filter shows that operation often corresponds to 70% to 80% of the filter’s total environmental […]

9.2.4.1 Separation It is important to be aware of the filter’s properties in different environ­ments. Figure 9.2 shows how, in the case of new filters, separation varies with particle size and filter class. The filter class is based on the average efficiency, and a new filter normally has much lower initial efficiency. In the case […]

9.2.3.1 Test Methods EUROVENT has always led the field in measuring and characterizing air filters. Since 1979 EUROVENT 4/5 has set the standard in Europe and pro­vided the basis for European Standard EN 779:1993, Specifications for Partic­ulate Air Filters for General Ventilation. EN 779:1993 in principle contains two different test methods. The filter is tested […]

Air is made up of a mixture of different gases and material from natural pro­cesses such as wind erosion, evaporation from the sea, earthquakes, and from human activity in the form of combustion products from processes and vehicles. 9.2.2.1 Sire of Particles The size of particles is often indicated in pm (microns). 1 firri = […]

A filter is a component of a system which, in conjunction with other compo­nents, can contribute toward a better indoor environment. 9.2.1.1 Ventilation System Protection Several major studies of indoor-air quality problems1 have shown that fil­ters would have been able to prevent blocked ducts, fans, and heat exchang­ers. Other major IAQ problems such as impurities […]

The need to separate impurities from air or other gases has increased as re­gards both the degree of separation and the necessity to separate both gases and finer particles. Correct dimensioning of filters is a prerequisite for the functioning of ventilation systems, for sensitive production, for protecting hu­mans and the environment, and for improving indoor […]

The main objectives are • Contaminant removal from the indoor space and associated processes • Supply of safe cleaned and/or treated air for the occupied spaces • Control of thermal and pressure conditions in treated spaces in a safe, reliable, and energy-efficient manner Aims of ductwork design are • Transport of air to and from […]