Carrier 37HS specifications HK08ZZ030, Multiple Unit Air¯ow Variation

S O OPEN

S O

MINIMUM CFM

STAR WHEEL

% CFM 120

100

	HK08ZZ030
40
80

%

CFM 120

100

40 80

MAXIMUM CFM LEVER VOLUME CONTROLLER

Fig. 84 Ð Minimum and Maximum Air¯ow Adjustments, 37HS Controller

Variation in Maximum Air¯ow Ð As explained in the Terminal Selection and Layout section, Moduline units in air series can be controlled individually with a volume controller at each unit, or with a master/slave combination, where one controller is used with multiple units. All the units on one controller must be of the same model (capacity).

In master/slave combinations, some variation in maxi- mum air¯ow among the terminals in air series will occur. The variation in maximum air¯ow is a function of the unit plenum size, the model, and the number of units in an air series on one controller. Table 17 shows the expected varia- tion from the unit with the smallest air¯ow to the unit with the largest air¯ow.

For single units with controller, the cfm variation from the lever setting is ± 10%.

Table 17 Ð Multiple Unit Air¯ow Variation

		APPROXIMATE AIRFLOW VARIATION (Cfm)
	PLENUM	LOWEST UNIT TO HIGHEST UNIT IN AIR SERIES*
MODEL			Number of Units in Air Series On
	SIZE (in.)
				One Controller
		2		3	4	5
	7 x 7	10		15	20	Ð
37HS1	9 x 9	10		15	20	25
	11 x 11	10		15	20	25
	7 x 7	20		Ð	Ð	Ð
37HS2	9 x 9	20		30	40	Ð
	11 x 11	20		30	40	Ð
	9 x 9	40		Ð	Ð	Ð
37HS4	11 x 11	40		60	Ð	Ð
	13 x 13	40		60	80	Ð

*Values shown are based on a typical short, straight duct run be- tween units. Variation shown may be affected if there are excessive duct pressure losses between units.

NOTE: The variation value shown in Table 17 for a given number of units of a certain model size (capacity) is the same for all size ple- nums used in an air series of recommended combinations for that model size. Thus, 3 units of model size 37HS2, plenum size 9 x 9, will have a maximum variation of 30 cfm; 3 units, plenum sizes 9 x 9 (2) and 7 x 7 (1) will also have a maximum variation of 30 cfm. A dash indicates that the quantity of a particular plenum size is not recom- mended in air series for that unit size.

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