Heat Controller HBH 072 - 120 manual Heat Controller, Inc, HBH Series, Submittal Data, HBH096

Heat Controller, Inc. HBH Series Submittal Data

Performance Data

Selection Notes

For operation in the shaded area when water is used in lieu of an anti-freeze solution, the LWT (Leaving Water Temperature) must be calculated. Flow must be maintained to a level such that the LWT is maintained above 42°F [5.6°C] when the JW3 jumper is not clipped (see example below). This is due to the potential of the refrigerant temperature being as low as 32°F [0°C] with 40°F [4.4°C] LWT, which may lead to a nuisance cutout due to the activation of the Low Temperature Protection. JW3 should never be clipped for standard range equipment or systems without antifreeze.

Example:

At 50°F EWT (Entering Water Temperature) and 1.5 gpm/ton, a 8 ton unit has a HE of 72,200 Btuh.

To calculate LWT, rearrange the formula for HE as follows:

HE = TD x GPM x 500, where HE = Heat of Extraction (Btuh); TD

=temperature difference (EWT - LWT) and GPM = U.S. Gallons per Minute.

TD = HE / (GPM x 500)

TD = 72,200 / (12 x 500)

TD = 12°F

LWT = EWT - TD

LWT = 50 - 12 = 38°F - Antifreeze must be used

HBH096

	WATER/BRINE				Heating - EAT 70°F
EWT	FLOW	PD	PD ft.	HC	kW	HE	LAT	COP
°F	gpm	psi
	12.0	1.7	4.0	96.7	7.17	72.2	95.9	4.0
50	18.0	4.5	10.3	101.9	7.27	77.1	97.4	4.1
	24.0	7.9	18.2	104.7	7.32	79.8	98.2	4.2

In this example, a higher flow rate will be required for EWTs at or below 50°F without antifreeze.

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