Document k6Rz3knRROjRQpeXZZGqxRLBb

American Society of Heating and Ventilating Engineers Guide, 1935 Having disposed of the accessory central fan conditioning appara, ` the balance of this chapter will concern only the unit air conditioner' defined in Chapter 41. ADVANTAGES AND USES OF UNIT AIR CONDITIONERS Unit air conditioners are suitable for commercial and comfort app[;S tions because they: permit installation without seriously disturbing building occupants, and they allow rearrangement or a change in capaci to suit changed requirements occasioned by new tenants. Tenants 1 even furnish their own installations and remove the apparatus from premises at the expiration of their leases. In some types of buildings, tjf installation costs are lower for unit conditioners than those for central (|f systems, and costs are further lowered in that there is'no need for spaced which to house a conditioning plant. The Choice between unit anfl 7o /?oom>y '>(?// Burner Fart Fig. 5, Oil Fired Unit central systems will, in many instances, require a close study of ins'f. lation conditions at the site, and a preparation of comparative cost estimates, in addition to a consideration of the more intangible factoS Industrial Uses The origin of the unit conditioner, like that of air conditioning i was in the industrial field for maintaining desired atmospheric condition in rooms or sections of manufacturing plants where structural limitatr or service requirements made a central system uneconomic. Indus applications continue to offer an important market for unit condition, in bakeries, candy factories, drug-manufacturing plants, laboraton produce-storage rooms, printing plants, and similar places. Commercial Uses The most active field for unit conditioners at the present time is, commercial establishments, such as barber and beauty shops, fun,, parlors, retail and specialty stores, and small restaurants, where incr patronage or larger purchases per customer offer economic justification first cost and operating expense. Unit Air Conditioners and Conditioning Systems -v" h ndling units installed overhead in Pullman cars; diners and 4i:We.alf'"ig m;ddle or at the ends of the cars which discharge the air `I? t tjjC ceiling level, are essentially unit conditioners. How- *lwn"ntall5L 0j special construction to meet space limitations and other ;ever,'hecau , unsuitable for general use and are not further reduirenients' * -discussed- VpejVfsfou3* aior recent development in the air conditioning industry has been T."e mnJj improved types of unit conditioners suitable, for apartments, in,new a ^ roomS| and offices. These uses demand apparatus that is ; homes, ^ unobtrusive appearance and in harmony with the room ^U^and furnishings, quiet in operation, automatic, and reliable. ' a' with all new major appliances for the home, problems of relatively s'first cost, of comparatively rapid obsolescence and of operating nehse demand the continuous close attention of manufacturers and of Tters interested in developing the . potential market. Unit conditioners restill distinctly in the pioneering stage where such problems must be met and solved if development--especially of residential units--is to * unwed as fast as it should. Public understanding of residential air con ditioning still requires cultivation in order to dispel fears of possible excessive operating costs and of possible high obsolescence due from frequent model changes. Progress in this direction is being helped by the ` increasing efforts of manufacturing, companies which are now spending Mage sums to insure sound promotion of unit conditioners. Likewise, the ^National Better-Housing Program inaugurated in 1934 is likely to prove of revalue to the air conditioning industry and to accelerate greatly the ' rate of public acceptance and installation of unit conditioners/ FUNCTIONS OF UNIT CONDITIONERS `/Unit air conditioners may be classified as the all-year unit, the summer j'unitjiand the winter unit. The all-year unit performs all of the functions Jof mr.air conditioning system; namely, cooling, dehumidification, heating, ^humidification, air circulation, air cleaning--with or without a supply of Mresti'air--and a simultaneous control of all functions. The summer unit mustprovide cooling, dehumidification, air circulation, and air cleaning; Ur unit must provide heating, humidification, air circulation, and air-deahing. Either of these seasonal-use units may or may not provide a jgshjsair supply and a simultaneous control of the functions. IjUjsome instances, winter-type units. equipped. with filters for air jning and with fresh air connections may be operated in summer for pnulation, but the system cannot then properly be said to provide aHjpar conditioning. It is important that the features and limitations of * " aPParatus be carefully explained to a prospective user, so that pointments and complaints concerning operating results may be sanded. aJpfl-fllnct'ons listed are performed by the unit conditioners offered by ffi||rent manufacturers in various ways, some of which appear in the IffliSSiBg outline. See the next few pages for more detailed explanations ing and heating theories and methods. 201