Lochinvar 3.5, 2.5 service manual Circulator sizing, Model, 20F 40F 60F

Installation & Operation Manual

5 Hydronic piping (continued)

Circulator sizing

The Crest heat exchanger does have a pressure drop, which must be considered in your system design. Refer to the graph in FIG. 5-1 for pressure drop through the Crest heat exchanger.

Figure 5-1Pressure Drop vs. Flow

CREST Pressure Drop Curve

	16
	15	FBN1500
Head)	14	FBN2000
	13	FBN2500
	12	FBN3000
of	11	FBN3500
(Feet
	10
	9
Drop
	8
	7
Pressure
	6
	5
	4
	3
	2
	1
	0
	0	50	100	150	200	250	300	350

Flow Rate (GPM)

Table 5A Sizing Information for Temperature Rise Applications_20°F, 40°F and 60°F

TEMPERATURE RISE APPLICATIONS

Model		BOILER					20°F		40°F				60°F
	CONNECTION SIZE				GPM		FT/HD	GPM		FT/HD		GPM	FT/HD
FB 1500		4"			138		3.4	69		1.5		46	1.0
FB 2000		4"			184		4.1	92		1.6		61	1.0
FB 2500		4"			230		4.6	115		1.3		77	0.7
FB 3000		4"			277		5.6	138		1.2		92	0.7
FB 3500		4"			323		7.5	161		1.2		108	0.7
						[Based on 92% AHRI Efficiency]
NOTICE		The pressure drop reflected in FIG. 5-1 is						NOTICE		It is required that boiler piping systems
		for the boiler only. Additional allowances
										utilize	Primary/Secondary or Fixed			or
		must	be made	for	piping,		especially if
										Variable Flow Primary			configurations	as
		sizing	pumps	for	Primary/Secondary
										shown in FIG.’s 5-2 thru 5-5. The use of

applications.	other boiler piping configurations could
	result in improper building and system flow
	rates leading to inadvertent boiler high limit
	shutdowns and poor system performance.

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