Selection Guide (Ylca And Ylha Plus) - York YLCA Series Technical Information

Selection guide (YLCA and YLHA PLUS)

Necessary information
The following information is needed to select a YLCA 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 the condensing 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 formulae:
Cooling capacity kW =
Selection example
A chiller is required to chill water from 13° C to 7° C, with a
cooling capacity of 5 kW.
Here are other design conditions:
Ambient air entering the condensing unit: 35° C
Gumming coefficient:
Altitude:
Table 10. Gumming coefficients
Evaporating unit
Gumming coeff.
Capacity factor
m °C/kW
2
0.044
0.088
0.176
0.352
Table 11. Altitude factors
Altitude (m) Capacity factor
0
600
1 200
1 800
2 400
20
l/h cold water x °C differential
860
0.044m
At sea level
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
Taking a quick look at Table 1 we can see that a YLCA-5 unit
gives an approximate required capacity of 5.38 kW.
As the factors appearing in Tables 10 and 11 are not appli-
cable, conditions will be as follows:
Cooling capacity:
Power consumed:
Water temperature:
Water flow:
Available pressure in hydraulic circuit of a unit.
- From Table 6 we infer that the YLCA - 5 MC, with a 771 l/h
flow, has an available pressure of 56 kPa.
Pressure drop in filter.
- From Table 7. 1" filter, we infer that with a 771 l/h flow, said
filter has a pressure drop of 1.3 kPa.
YLHA PLUS selection method
1. Determine the correct size of the YLHA PLUS unit by
selecting a model from Tables 3 and 5 that is closest to
the cooling and heating capacities required in the design
conditions of the water outlet and air intake tempera-
tures.
2. Apply gumming correcting factors (Table 10) and altitude
(Table 11) to the capacity and power values that appear
in the corresponding capacity tables in cool and heat.
°C/kW
2
Make sure the corrected capacity is still sufficient for your
needs.
3. Using the corrected capacities of the unit, select the de-
sign temperature differential, or the flow.
4. Check to make sure that these selections are within the
YLCA/YLHA PLUS operating limits.
YLHA PLUS selection example
A YLHA PLUS 5 heat pump operating at a 35° C ambient
temperature should chill water from 13° C to 7° C, with a
5 kW cooling capacity.
A 4 kW heating capacity is required in 0° C design ambi-
ent temperature and a hot water output temperature of
45° C.
The gumming coefficient is 0.044 m² °C/kW, with the unit
operating at sea level (no corrections).
With a quick glance of capacity Tables 3 and 5, we see that
a YLHA PLUS 5 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
5.38 kW
1.87 kW
13° C to 7° C (∆t = 6)
5.38 x 860
= 771 l/h
6
= 5.40 kW
= 1.91 kW
= 13° C to 71 C (∆t: 6° C)
= 774 l/h
= 4.15 kW
= 1.88 kW
45° C
4.15 x 860
=
774
= 40.4° C
= 4.60° C