Heatcraft Refrigeration Products HCS manual Coil Perfromance- Heat Reclaim MBH/SQ FT

Coil Perfromance- Heat Reclaim MBH/SQ FT

Table 14

Heat Reclaim Coil Selection Example:

Select reclaim coil for Size 26 air handler at 13280 CFM, 344 MBH reclaimed at 45°F. Temperature Difference.

A.Change the application’s requirement at application’s TD to adjusted requirement at 50°F. TD. Use Table 15:

344/0.9 = 382.2 MBH (adjusted)

B.Divide the adjusted MBH by the coil face area:

382.2/ 26.56 = 14.4 MBH (adjusted) per square foot

C.Find the coil air speed:

13280 / 26.56 = 500 fpm

D.Select coil rows and fins per inch from Table 16 at coil air

speed and with enough MBH to meet the MBH (adjusted to 50°F. TD) per square foot

Air Handler	Type A Large	Type 5 Large
Unit	Coil Face Area	Coil Face Area
Size	Square Feet	Square Feet
03	3.13	3.00
06	5.76	5.69
08	7.81	7.50
10	9.77	9.38
12	12.40	11.69
14	14.58	13.75
18	17.71	17.50
20	20.05	19.25
26	26.56	25.50
34	33.65	34.00
41	40.73	40.38
50	50.63	49.50
65	64.58	64.58
75	75.35	74.92

figured in step B:

Select 3 row 8 fin per inch coil with capacity of 14.56 MBH per square foot at 50°F. TD.

For this application, capacity equals: (14.56 x 26.56 x 0.9) or 348 MBH for size 26 at 45°F. TD.

E.When ordering, please specify refrigerant type and the total heat of rejection for each reclaim circuit. Or specify the per cent of the total heat of rejection that is reclaimed for each circuit.

Table 15 Heat reclaim correction factor for temperature difference between air and refrigerant.

Temperature Difference	20	25	30	35	40	45	50
Correction Factor	0.4	0.5	0.6	0.7	0.8	0.9	1.0

60

1.2

Table 16
Refrigeration Gas
Heat Reclaim		1/2" and 5/8" tube, 50°F TD, entering air to condensing temperatire
			Type A and Type 5, hot gas reclaim, heating capacities
					MBH per SQ FT of coil face area
				FPM, Type A Coils (1/2" DIA.)						FPM, Type 5 Coils (5/8" DIA.)
	Rows	FPI	400	450		500	550	600	400	450	500	550	600
		6	7.70	8.18		9.43	9.90	10.25	9.25	9.85	10.41	10.91	11.41
		8	8.90	9.45		10.90	11.38	11.85	10.04	10.70	11.33	11.92	12.47
	2	10	10.40	11.05		12.15	12.73	13.18	11.12	11.93	12.68	13.37	14.03
		12	11.70	12.45		13.13	13.77	14.35	12.20	13.13	13.99	14.80	15.56
		14	12.88	13.73		14.48	15.18	15.83	13.23	14.28	15.26	16.18	17.04
		6	11.08	11.96		12.88	13.50	13.98	12.27	13.13	13.98	14.77	15.52
		8	12.60	13.60		14.56	15.25	15.90	13.17	14.13	15.07	15.96	16.79
	3	10	13.93	14.95		15.93	16.80	17.63	14.30	15.48	16.58	17.61	18.58
		12	14.91	16.02		17.08	18.03	18.95	15.40	16.73	17.98	19.16	20.28
		14	16.08	17.30		18.50	19.55	20.58	16.39	17.87	19.28	20.60	21.86
		6	13.27	14.35		15.53	16.38	17.18	14.50	15.66	16.77	17.81	18.79
		8	14.98	16.21		17.43	18.47	19.47	15.39	16.66	17.89	19.04	20.12
	4	10	16.20	17.48		18.75	19.92	21.07	16.50	17.96	19.36	20.68	21.94
		12	17.47	18.73		19.98	21.25	22.50	17.48	19.11	20.68	22.17	23.58
		14	18.57	19.95		21.30	22.65	23.97	18.32	20.11	21.83	23.48	25.05
		6	16.41	17.83		19.58	20.78	21.90	17.38	19.10	20.62	22.09	23.49
		8	18.35	19.93		21.50	23.10	24.67	18.10	19.96	21.61	23.21	24.74
	6	10	19.13	20.90		22.63	24.20	25.75	18.96	21.00	22.83	24.62	26.33
		12	19.80	21.70		23.58	25.23	26.87	19.65	21.83	23.82	25.78	27.67
		14	19.87	22.01		24.02	26.02	27.95	20.18	22.48	24.61	26.72	28.75
		6	18.25	20.08		21.75	23.45	25.08	18.93	21.51	23.02	24.69	26.42
		8	19.29	21.31		23.16	25.04	26.86	19.49	21.82	23.82	25.60	27.47
	8	10	20.04	22.23		24.24	26.30	28.28	20.11	22.57	24.74	26.67	28.71
		12	20.51	22.82		24.95	27.14	29.26	20.58	23.12	25.43	27.63	29.68
		14	20.82	23.22		25.44	27.72	29.95	20.91	23.51	25.93	28.25	30.45

This table for R-22, for R404A & R507, multiply MBH by 0.98

For heat reclaim capacities at other temperature differences, multiply by factor in Table 15.

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