Table 9. Gumming Coefficients - York YCSA 120 T Technical Information

Table 9. Gumming coefficients

Evaporating unit
Gumming coeff.
Capacity factor
m °C/kW
2
0.044
0.088
0.176
0.352
Table 10. Altitude factors
Altitude (m) Capacity factor
0
600
1 200
1 800
2 400
Selection guide (YCSA and YCSA-H)
Necessary information
The following information is needed to select a YCSA/YCSA-H
water chiller:
1. Cooling capacity needed.
2. Design cold water input and output temperatures.
3. Design water flow, if any of the temperatures in above
point 2 is unknown.
4. Design input temperature of air to air conditioning unit.
Normally, this will be the design ambient temperature of
summer air, unless influenced by the situation or other
factors.
5. Altitude above sea level.
6. Design gumming coefficient of the evaporating unit.
Note: Points 1, 2 and 3 should be related by means of the
following:
Selection example
A chiller is required to chill water from 13°C to 7°C, with a
Coolling capacity kW =
cooling capacity 117 kW.
Here are other design conditions:
Ambient air entering the
condensing unit
Gumming coefficient:
Altitude:
Taking a look at Table 1 we can see that YCSA-120, unit gives
an approximate required capacity of 117 kW.
Comp. absorbed
power factor
1.000 1.000
0.987 0.995
0.964 0.985
0.926 0.962
Comp. absorbed
power factor
1.000 1.000
0.987 1.010
0.973 1.020
0.958 1.029
0.943 1.038
l/h cold water x °C differential
860
35°C
0.044 m °C/kW
2
At sea level
As the factors appearing in Table 9 and 10 are not applicable,
conditions will be as follows:
Cooling capacity:
Power consumed:
Water temperature:
119 x 860
Water flow:
Available pressure in hydraulic circuit of a unit with kit.
- From Table 6 we infer that the YCSA 120 TP, with a 7 052
l/h, flow, has an available pressure of 279 kPa.
Pressure drop in hydraulic circuit of a unit without kit.
- From Table 7 we infer that the YCSA 120 T, with a 17 056
l/h, flow, has a pressure drop of 23 kPa.
Pressure drop in filter.
- From Table 8, 2 1/2" filter, we infer that with a 17 056 l/h
flow, said filter has a pressure drop of 2.4 kPa.
YCSA-H selection method
1. Determine the correct size of the YCSA-H unit by selecting
a model from Tables 4 and 5 that is closest to the cooling
and heating capacities required in the design conditions
of the water outlet and air intake temperatures.
2. Apply gumming correcting factors (Table 9) and altitude
(Table10) to the capacity and power values that appear
in the corresponding capacity tables in cool and heat.
Make sure the corrected capacity is still sufficient for your
needs.
3. Using the corrected capacities of the unit, select the
design temperature differential, or the flow.
4. Check to make sure that these selections are within the
YCSA/YCSA-H operating limits.
YCSA-H selection example
A YCSA-H heat pump operating at a 35°C, ambient tempera-
ture should chill water from 13°C to 7°C, with a 112 kW cooling
capacity.
A 85 kW heating capacity is required in 5°C design ambient
temperature and a hot water output temperature of 45°C.
The gumming coefficient is 0.044 m
operating at sea level ( no corrections).
With a quick glance of capacity tables 4 and 5, we see that
a YCSA-H 120 heat pump gives the approximate required
capacities:
Cooling capacity
Total unit absorbed power =
Cold water temperature
Hot and cold water flow
Heating capacity
Total unit absorbed power
in heat mode.
Hot water output
temperature
Hot water temp.
differential
Thus, hot water return
temperature is
119 kW
43 kW
13°C a 7°C (Dt = 6)
=17 056 l/h
6
°C/kW, with the unit
2
= 114 kW
43.3 kW
= 13°C a 7°C (Dt = 6°C)
= 16 340 l/h
= 84.9 kW
= 35.6 kW
= 45°C
84.9 x 860
= = 4.47°C
16 340
= 40.5°C
17