York YLCC 42/62/82/102/112, 122 Correcting factors, Factors with water and glycol, Foul factors

Correcting factors

Foul factors

	Evaporator
Foul factor m2	Capacity factor	Absorbed power
°C/kW		factor comp.
0.044	1.000	1.000
0.088	0.987	0.995
0.176	0.964	0.985
0.352	0.926	0.962

Altitude factors

Altitude (m)	Capacity factor	Absorbed power
		factor comp.
0	1.000	1.000
600	0.987	1.010
1 200	0.973	1.020
1 800	0.958	1.029
2 400	0.943	1.038

Correcting factors for real temperature of coil air intake at flows other than nominal

% Flow	70	80	90	100	110	120	130
Correction in °C on real	5	3	1.5	0	-1	-2	-2.5
temperature of coil
intake temperature

Factors with water and glycol

Glycol can be used for antifreeze protection, or as brine for operation at low temperatures. We recommend the use of water and glycol when the discharge water temperature is below +6° C. The “Solution with glycol/freezing point” table gives the freezing point of water with glycol, and the “Recom- mended glycol concentration” table shows the glycol concen- tration needed, depending upon application.

Glycol contains anticorrosive and antifoam components that favour circuit protection.

Solution with glycol/freezing point

% Glycol weight per weight	Freezing point °C
0	0
10	-4
20	-10
30	-17
35	-20
40	-25
50	-37

A mixture of glycol and water has a freezing point below that of pure water. Depending upon the concentration of glycol in the solution, an even lower freezing point can be achieved and this protects the circuit when the unit is off and ambient temperature is low (below 0° C). This table indicates freezing point in accordance with glycol concentration. This concen- tration appears in % per weight.

Recommended glycol concentration

LWT °C	Glycol % per weight
6°C > LWT > 0°C	20
0°C > LWT > -5°C	30

The glycol concentration in the water should be checked regu- larly to ensure adequate protection of the chiller.

Correcting factors

			Nominal capacity
Ethylene			correcting factors
glycol
	LWT		Air temperature at
percentage
by weight		condenser intake (°C DB)
(%)
		25	35	45
	5	1.045	0.902	0.754
	4	1.004	0.866	0.726
	3	0.962	0.83	0.697
20
	2	0.921	0.794	0.669
	1	0.879	0.758	0.64
	0	0.838	0.722	0.612
	-1	0.795	0.681	0.574
	-2	0.764	0.652	0.545
30	-3	0.734	0.623	0.515
	-4	0.703	0.594	0.486
	-5	0.673	0.565	0.457

Water flow correcting factors for ethylene glycol solu- tions

Ethylene glycol	Correcting	factors
percentage by weight
	Water flow	Pressure drop
(%)
20	1.035	1.16
30	1.075	1.27

20