Bryant GT-PG (50YE) manual Performance Data Selection Notes

GT-PG (50YE) Series

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		ting		Performance capacities shown in thousands of Btuh
to a level such that the LWT is maintained above 40°F						Heating - EAT 70°F
[4.4°C] when the JW3 jumper is not clipped (see example
below). Otherwise, appropriate levels of a proper anti-freeze	EER		HW	Airflow	HC	kW	HE	LAT	COP	HW
should be used in systems with leaving water temperatures				CFM
				1575	47.0	5.12	30.6	98	2.69	5.3
of 40°F or below and the JW3 jumper should be clipped.
				2100	48.3	4.68	32.5	91	3.02	4.5
This is due to the potential of the refrigerant temperature		22.3	-	1575	50.7	5.21	33.9	100	2.85	6.2
being as low as 32°F [0°C] with 40°F [4.4°C] LWT, which may	22.5		-	2100	52.1	4.77	36.0	93	3.20	5.3
	23.6		-	1575	52.8	5.26	35.8	101	2.94	6.2
lead to a nuisance cutout due to the activation of the Low	23.7		-	2100	54.2	4.81	37.9	94	3.30	5.3
Temperature Protection. JW3 should never be clipped for	24.2		-	1575	53.9	5.28	36.8	102	2.99	6.2
standard range equipment or systems without antifreeze.	24.4		-	2100	55.4	4.83	39.0	94	3.36	5.3
		22.3	-	1575	57.6	5.36	40.1	104	3.15	7.1
	22.5		-	2100	59.2	4.91	42.6	96	3.53	6.1
Example:	23.5		-	1575	60.4	5.42	42.6	105	3.26	7.1
	23.7		-	2100	62.0	4.96	45.2	97	3.66	6.1
At 50°F EWT (Entering Water Temperature) and 1.5 gpm/	24.1		-	1575	61.9	5.46	44.0	106	3.33	7.1
	24.3		-	2100	63.6	4.99	46.7	98	3.74	6.1
ton, a 3 ton unit has a HE of 22,500 Btuh. To calculate LWT,		20.5	3.6	1575	65.2	5.52	47.0	108	3.46	7.9
rearrange the formula for HE as follows:	20.6		3.8	2100	67.0	5.05	49.9	100	3.89	6.8
	22.0		3.4	1575	68.7	5.60	50.1	110	3.60	7.9
	22.2		3.5	2100	70.5	5.12	53.2	101	4.04	6.8
HE = TD x GPM x 500, where HE = Heat of Extraction (Btuh);	22.8		3.1	1575	70.6	5.64	51.8	112	3.67	7.9
	22.9		3.2	2100	72.5	5.15	55.0	102	4.12	6.8
TD = temperature difference (EWT - LWT) and GPM = U.S.		18.0	4.4	1575	73.3	5.69	54.2	113	3.77	8.8
Gallons per Minute.	18.1		4.6	2100	75.2	5.21	57.5	103	4.24	7.5

TD = HE/(GPM x 500)

TD = 22,500/(4.5 x 500)

TD = 10°F

LWT = EWT - TD

LWT = 50 - 10 = 40°F

In this example, as long as the EWT does not fall below 50°F, the system will operate as designed. For EWTs below 50°F, higher flow rates will be required (open loop systems, for example, require at least 2 gpm/ton when EWT is below 50°F).

Antifreeze Correction Table

			Cooling		Heating		WPD
	Antifreeze
Antifreeze Type			EWT 90°F		EWT 30°F		Corr. Fct.
	%
							EWT 30°F
		Total Cap	Sens Cap	Power	Htg Cap	Power
Water	0	1.000	1.000	1.000	1.000	1.000	1.000
	5	0.995	0.995	1.003	0.989	0.997	1.070
Propylene Glycol
	15	0.986	0.986	1.009	0.968	0.990	1.210
	25	0.978	0.978	1.014	0.947	0.983	1.360
	5	0.997	0.997	1.002	0.989	0.997	1.070
Methanol
	15	0.990	0.990	1.007	0.968	0.990	1.160
	25	0.982	0.982	1.012	0.949	0.984	1.220
	5	0.998	0.998	1.002	0.981	0.994	1.140
Ethanol
	15	0.994	0.994	1.005	0.944	0.983	1.300
	25	0.986	0.986	1.009	0.917	0.974	1.360
	5	0.998	0.998	1.002	0.993	0.998	1.040
Ethylene Glycol
	15	0.994	0.994	1.004	0.980	0.994	1.120
	25	0.988	0.988	1.008	0.966	0.990	1.200

GT-PG	Bryant: Whatever it Takes.
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