Lochinvar 81 - 286 Near boiler piping connections, Circulator sizing, Indirect water heaters

Installation & Operation Manual

6 Hydronic piping

13. Indirect water heaters:

The Knight boiler may be piped to an indirect water

heater to heat domestic hot water with the space heat

transfer medium. As depicted on pages 39 through 45

It is up to the installer to ensure the CAUTION minimum system flow is not less than the

minimum boiler flow at any time.

there are two options when utilizing an indirect water
heater.
A.	The space heating piping will branch off to flow the
	space heat transfer medium through a single wall
	heat exchanger coil inside the indirect water heater.
B.	The indirect water heater is connected to the system
	supply piping. A pump controlled by the Knight
	boiler’s control will regulate the flow of water
	through the indirect water heater. The indirect water

￿WARNING

The National Standard Plumbing Code, the National Plumbing Code of Canada and the Uniform Plumbing Code limit the pressure of the heat transfer fluid to less than the minimum working pressure of the potable water system up to 30 psi maximum. Also, the heat transfer fluid must be water or other non-toxic fluid having a toxicity of Class 1, as listed in Clinical Toxicology of Commercial Products, 5th Edition.

heater’s temperature will be regulated by the Knight

boiler’s control.

The Knight boiler is pre-configured to control the operation of the DHW pump with Domestic Hot Water Prioritization programming. The DHW programming is designed to control and balance the space heating demand by switching between DHW and space heating.

Lochinvar offers the Squire which is a series of indirect water heaters. The Squire features a stainless steel vessel with a single wall stainless steel heat exchanger.

Near boiler piping connections

14.Y-Strainer:

Field supplied. A Y-strainer or equivalent multipurpose strainer is recommended at the inlet of the heat exchanger to remove system particles from older hydronic systems and protect newer systems.

Circulator sizing

The Knight boiler heat exchanger does have a pressure drop, which must be considered in your system design. Refer to the graph in FIG. 6-3 for pressure drop through the Knight boiler heat exchanger.

Figure 6-2ANear Boiler Piping w/Y-Strainer			Figure 6-2BNear Boiler Piping w/Low Loss Header
				SYSTEM SENSOR		M
						E
						T
						S
				AIR SEPARATOR		Y
			AIR VENT VALVE			S	M
					O
					T		E
						T
						S
						Y
						S
	M					M
						O
	E					R
	T		LOW LOSS HEADER			F
	S
	Y
	S
	M		(TYPICAL)
	O
	R
	F
					FILL VALVE
Y-STRAINER
(RECOMMENDED)
SYSTEM SENSOR	DOMESTIC HOT
AIR SEPARATOR	WATER PUMP			DRAIN	EXPANSION TANK
		M		(TYPICAL)
SYSTEM		O
		R
		F
PUMP	BOILER	INDIRECT		DRAIN VALVE
	PUMP	DOMESTIC
		HOT WATER
M		TANK			M
	O				O
E				R
T	T			F
S					INDIRECT
Y
OS
T					DOMESTIC
			Y-STRAINER		HOT WATER
			(RECOMMENDED)
				O
				T
			BOLIER PUMP
	DRAIN
	(TYPICAL)
	TO FLOOR
	DRAIN
				TO FLOOR
				DRAIN
36