Stimmen - 3, Durchschnittliche Bewertung: 4.3
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Anleitung Zusammenfassung
. 600,000 Btuh Sensible Load (Req’d SHC) . . . 430,000 Btuh Temperature Air Entering Condenser....................95 F Temperature Air Entering Evaporator — edb.............77 F db Temperature Air Entering Evaporator — ewb ........... 64 F wb Evaporator Air Quantity .......20,000 cfm External Static Pressure........1.12 in. wg Length of Interconnecting Refrigerant Piping (Estimate) .......90 ft Electrical Power Source, Volts/Phase/Hertz............ 460/3/60 HEATING Heating Load............. 900,000 Btuh Temperature Air Entering Coil (edb) ....................58 F Steam Pressure................. 5 psig II Select condensing unit/fan coil combination. Enter the Systems Index at the desired cfm (20,000). Select the condensing unit(s) and fan-coil system that meets or exceeds the grand total load (600,000 Btuh). In this example, system no. 48 would be selected — two 38AD 024 and one 38AD016 condensing units and a 40RR054 fan-coil, yielding a nominal capacity of 632,000 Btuh. To determine whether this system will fully satisfy the cooling requirements, enter the combination ratings, system no. 48, page 9, at 20,000 cfm and 95 F condenser entering air temperature. By interpolation, at SYSTEMS INDEX ¡38 38 38 338 38 38 38 •XÿÿC'Âi*: s'w&fr: WSi$C«8§ Æ W SM tt mm 38 38 tisi wm iSiSiâ. CONDENSING UNIT(S) GR006 BA008 BA009 _ _ G~^-—- BA008 BA009 AD012 AD012 AD014 AD016 AD012 AD014 AD016 AD024 AD016 AD012 (2) AD024 AD028 AD024 AD012 (2) AD028 AD016 & AD012 AD034 A DO 16 (2 )_ ÂD028 ...... AD016 & AD012 AD034 AD016 (2) AD024 & AD016 AE044 AD034 AD012 (3) AD016 & AD024 AD016 & AD012 (2; AE044 AD016 (2) & AD012 AD016 & AD028 AD016 & AD034 AD016 (3) AE054 AE044 AD016 (2) & AD012 AD016 & AD034 AD016 (3) AD024 & AD034 AE054 AD024 (2) & AD012 AD024 (2) & AD016 AE064 FAN COIL 40 BA 009 40 RR008 40 RR012 40 RR016 40 RR024 40 RR028 40 RR034 40 RR044 40 RR054 NOM CFM 2(32(ÿ 3.400 3.400 2,360* 3.000 3.000 Ä000 4,500“ 4.000 4.000 4 ’ 950* 6.000 6,000 6,000 8,000 10,000 12,000 16,000 20,000 ARI OR NOM TC _____ .. 88 100_ 87 98 110 Î20*t’" 144 157 "132* t " 166 181 216 196 238 238 279 " 249 252 300 300 325 335 312 313 342 359 393 422 378 392 429 434 451 479 502 498 510 524 "481 512 537 557 579 567 590 632 638 EER* ’¿7“ 9 0 7 6 7 0 9 5 8 2 To' 8 6 EER — Energy Efficiency Ratio TC — Total Capacity (1000 Btuh) *ARI capacities, Energy Efficiency Ratios rated in accordance with latest ARI Standard 210 ■(•For units operating at 208 v, deduct 1000 Btuh from capacity rating © Carrier Corporation 1975 Form 38AD-5XA 64 F evaporator entering air wb temperature, the system has a total capacity (TC) of 600,800 Btuh, and a calculated sensible heat capacity (SHC) of 498,800 Btuh. For close-coupled systems (15 ft or less of interconnecting pipe), an additional 2% may be added to both TC and SHC. As this system is not close-coupled, the ratings are used directly from the combination ratings. At this point, the sensible heat capacity is adjusted for the evaporator entering air db temperature. For 20,000 cfm, the bypass factor is 0.18. The adjusted sensible heat capacity is: Adj SHC = SHC + [1.09 x cfm x (1—bf) x (edb-80)] = 498,800 + [1.09 x 20,000 x (1 —.18) x (77-80)] = 498,800 — 53,600 = 445,200 Btuh Therefore, the selected system will meet all cooling requirements. Ill Find heating capacity of selected fan-coil unit. Enter Table 3, page 10, for 40RR054 and 20,000 cfm. A one-row nonfreeze steam coil will deliver 915,000 Btuh based on 60 F entering air temp, and 2 psig steam. To find the corrected heating capacity, enter Table 1, page 10, for steam coils at 5 psig steam and 58 F entering air temperature. By interpolation, the correction factor is 1.062. Corrected capacity = 915,000 x 1.062 = 971,700 Btuh T . . „ ... corrected capacity Leaving air db = edb + ———-£-- 1.09 x cfm = 102.6 F The heating coil has sufficient capacity and the leaving air db is less than the maximum temperature of 140 F. IV Determine fan rpm and bhp. Refer to Table 14, page 17, for a 40RR054 at 20,000 cfm and 1.12 in. wg external static pressure, plus 0.07 in. wg for the heating coil (Table 4), indicates a fan rpm of 828 and requires 12.6 bhp. As this rating point is within the shaded area, the fan drive must be selected and purchased locally. V Determine size of liquid and suction lines. Table 11, page 14, indicates the pipe sizes for the various condensing units. These sizes are based on an equivalent length equal to the maximum length indicated plus 50% for fittings. A more accurate estimate may result in smaller pipe sizes. Enter the table with the condensing unit (38AD024) and the estimated length of interconnecting pipe (90 ft). The suction line will be 2 1/8-in. OD and the liquid line is 7/8-in. OD. Similarly, for the 38AD016, the suction line is 2 1/8-in. OD and the liquid line is 7/8-in. OD. If a 38AD034 —...