York YCWS manual Selection Data, Guide to Selection, Selection Rules, Cond Fouling Factors

Selection Data

GUIDE TO SELECTION

Complete water chilling capacity ratings for YORK YCWS chillers are shown on the following pages to cover the majority of job requirements. For any application be- yond the scope of this Engineering Guide, consult your nearest YORK Office.

SELECTION RULES

1.RATINGS - YCWS 200, 230 380, 460 & 575-3-60 rat- ing are certified in accordance with ARI standard 550/ 590, at the ARI standard condition. Rating not at stan- dard ARI conditions are rated in accordance with ARI rating procedures. These ratings may be interpolated but should not be extrapolated.

2.COOLING WATER QUANTITY - Ratings are based on 10ºF chilled water range. Use the chilled water correction factors (below) for other ranges except as limited by water pressure drop, minimum or maximum water flows for the cooler.

3.CONDENSER WATER QUANTITY – Rating are ap- plicable from 2 to 4 gpm/ton as limited by water pres- sure drop or minimum or maximum water flows for the condenser. Using the tabulated MBH, the Cond. GPM is calculated as follows:

MBH x 2

Cond. GPM = Cond. Water Range (ºF)

4.FOULING FACTORS – Rating are based on 0.0001 evaporator and 0.00025 condenser fouling factor. For other fouling factors, consult the table below or con- tact your YORK representative.

EVAP FOULING FACTORS

			0.0001		x	0.00025
	Temp		Tons	Compr		Tons	Compr
Split				kW			kW
		6	0.9692	1.0015		0.9972	1.0001
8			0.9849	1.0008		0.9980	1.0001
10			1.0000	1.0000		0.9982	1.0001
12			1.0133	0.9993		0.9978	1.0001
	14		1.0248	0.9986		0.9979	1.0001

Note: Temperature split factors @ 44ºF Leaving Chilled Liquid Temp

(LCLT)

COND FOULING FACTORS

			0.00025		x	0.0005
	Temp		Tons	Compr		Tons	Compr
		Split		kW			kW
8			0.9998	1.0004		0.9957	1.0072
10			1.0000	1.0000		0.9959	1.0068
12			1.0001	0.9998		0.9961	1.0065
14			1.0001	0.9998		0.9965	1.0060

Note: Temperature split factors @ 95ºF Leaving Condenser Water Temp (LCWT).

METHOD OF SELECTION

If the duty requires a 10ºF range on both the cooler and condenser, see “Ratings”. For water ranges other than 10ºF, use the following procedure.

1.Determine capacity required from the following for- mula

Capacity (tons) =	GPM x Chilled Water Range (ºF)
	24

2.After applying any fouling factor corrections, the ac- tual condenser heat rejection may be determined as follows:

Heat Rejection (Btuh) = (Tons x 12,000) + (kW x 3415)

Heat Rejection (MBH) =	Heat Rejection (Btuh)
	1000

=(Tons x 12) = (kW x 3.415)

3.Determine condensing water requirements for water cooled models as follows:

Condenser Tons =	Heat Rejection (MBH) x 1000
	15,000
Cond. Water GPM =		Condenser Tons x 30
		Condenser Water Range (ºF)
Or combine the two formulas:
Cond. Water GPM =		MBH x 2
		Condenser Water Range (ºF)

12 YORK INTERNATIONAL