Document 2qKBKEwMDoOOmXMJN81w93Dr7

288 CHAPTER IS - 1946 Guide also gives the total heat gain intb an air conditioned space when 78 F is maintained indoors, resulting from the effect of both radiation and air to air transmission. These values result from A.S.H.V.E. Laboratory data l. and apply for expected design radiation intensity, and for a design day having a maximum temperature of 95 F. The resulting heat gains are averages for four typical glass block designs, two having smooth exterior faces, and the other two having exterior ribbed faces. Heat Emission of Occupants The heat and moisture given off by human beings under, different states of activity are shown in various tables and figures of Chapter 12 which covers the physical and physiological principles of air conditioning. It will be observed, from these data that the rate of sensible and latent heat emission by human beings varies greatly depending upon state of activity. In many applications this component becomes- a large per.centage'of total load. Metabolic rates are markedly variable for some extreme environmental conditions and this is another important factor which must be considered in cooling toad computations.. Consideration should be given to the typical age and sex of the occupants (whether men, women, or children) and the duration of-the occupancy (since for short occupancy applications the extra heat and moisture brought in by people may be an important factor in the load). Heat Introduced by Outside Air Heat and, moisture are added by the outside air introduced for venti lation purposes and also by infiltration air entering the building through cracks, openings, arid doors. The volume of air entering due to infiltration may be estimated from data given in Chapters 8 and 14. Information on the amount of outride air required for ventilation will be found in Chapter 12. In general, ventilation air is supplied on a per person basis at a rate between 5 and 30 cfm per person (10 to 20 cfm being normal good practice), its specific amount depending upon the amount of contamination by smoke, foododors, etc. Electrically Heated Equipment 2. Baker al Oven. --. 5. Wanning Receptacle- s, stram Table-Water Bath Type------ __-------------------------- -- 10. Fry Kettle----------- ------------ ---------------- -------------12. Sandwich 14. Toaster--Continuous. D..w_Km w 70 20 30 50 80100 75 70 40.. 60 : 50 100 16; Permanent Wave Machine in Beauty Parlor--24-25 w Units_ -- ' 18# 80% 1025 90% 80% 100% "65% 90% "75% ' 90% 90% 90% 2050 2050 20% 100% 100% 10% 0% --35% 10%.. 100% 100% 100% 100% 100% "25% 10% 1U% 10% ____ 100%. " 100% 100% 100% 2050 -- Gas Burning Equipmentb 17. Gas Heated Oven-Baking-------- --jg SEES 70 . 35... 72% 100% 50 45% 19 Hot*o^Closed Top--per Burners----- :------ no vent 100 . . 45% i. nut - gravity vent connection 70 50% 5000 3000 ' ' ' 500 -a23?.' Pnluatt<e.wWarimrneirfr ....... - --no vengt rcaovnintyecvteionntconne61c00ti-on 90% 100% 24. Steam Tabl^-Water Bath Type------- SSS 60 . 55% 42 50% 25. Frying Griddles- - Jg %* 75 52 : 81% . 90% a>< gn, Krttlf* ^ .no ventconnelcition gravity ventconnection 72% 80% 2500 2250 . . 2250 ___ 180 28% . 55% . 50% 5000 3000 . 500 10% 0% 45% 50% a 28% 20% 2500 250 250 100% 100% 100% 100% 100% 10.000 6000., 1 100% 100% 100% 100% \ 100% 100% 100% 100% .5000 2500 2500 . . ; Steam Healed EquipmentP > As outside air is introduced through the air conditioning apparatus it tends to decrease infiltration by building up the pressure within the building. Usually, however, some infiltration still occurs unless the amount of outside air is very large. ; For instance, it is necessary to supply between 2,000 and 3,000 cfm of outside air through the apparatus to prevent infiltration through a single swinging door.. As no demonstrated factors are generally available for the effect (on infiltration) of outside air 31. Steam Heated Surface Not Polished--per Square Foot of ` Surface__ ::!_______ 32. Steam Heated Surface Polished--per Square Foot of Surface 33. Insulated Surface--per Square Foot. 34. Bare Pipes.-Not Polished---per Square Foot of Surface-.... --: 35. Bare Pipes. Polished--per Square Foot of Surface.-...--._ 36. Insulated Pipes--per Square Foot--________ J___ _ 37. Coffee Urmn--Large., 18 imn.DDiiaam.--bSmingile iDjrruumm-: 3**8. CoffeeUm--Small;-1192 in. nDtiam.--Sincgle Drumm- 39. Egg Boiler--per Egg Compartment---------------- -- 330 : 130 80 400 . 220 110 2000 1200 2500 300 ' 0 .0 0 0 0 0* 2000 1200 2500 800 '330 130 80, 400 220. 110 4000 2400 5000 1100 introduced through the apparatus, it is necessary to use judgment in assigning an effect. . .. Miscellaneous In .determining the amount of outside air which must be drawn through the apparatus the amount of air needed for ventilation is established and it is normally possible to subtract from this the assumed amount of 41. Heat Liberated By Food per Perton, as in a Restaurant----- ~ 42. Heat Liberated from Hot Water used direct and on towels 30; 100 30 200 60 ; 300 infiltration: The division between the ventilation provided by infiltration '1 and by outside air is important to the designer, since the infiltration adds directly to the room sensible and moisture toads, whereas the outside air brought through the apparatus affects only the refrigeration load and the dehumidifier performance (except where shallow coils are used,; in which case a portion of the outside air ineffectively "by-passed" through the coil): ' I 1 Heat gain from electric or gas residential ranges or cooking staves.depends on size oi uie uuuuy.-ovuveconomic status of the individual, time of day for principal meal,'and whether the equipment is manually or automatically controlled. Total heat gain will probably not exceed'40 per cent name-plate rating. Pei .cent sensible and latent heat will depend upon use of equipment; dry beat; baJrfng or boiling. ^Name-plate ratings oi gas burning equipment' can' be obtained from a' Directory of Approved Gas Aapppplliiaannces anddLLiissted Accessories, obtainamble firom Aamwewricoaun GasAssociation. `' . eSteam Require--m---e--n-*t--s oif rP--roc--es.s. Equipment. i?ReportoofftthheeCCoommmmeerrcdiuaJl. RRelations Committee. Nolumot DistricFllJtint Association (Budinl. Pipint and Asr CondUummt. November. 1942,-p. 675).