FORM 145.05-EG2 (618)
JOHNSON CONTROLS
15
Selection Procedure
1. Design Criteria should be available to select a unit. These criteria include:
a. Design airflow
b. Entering air conditions
• Summer
• Winter (if heating is required)
c. Total and sensible loads
d. Condenser water entering and leaving temperatures
e. External static pressure
f. Factory installed options required
2.
Based on design air flow, select the smallest unit with maximum air flow higher than
design air flow and minimum airflow lower than design air flow from Unit Physical
Data Tables on
page 19
through
page 21
. Please note that standard and high ef-
ficiency units of the same size have different air flow limits.
3.
Divide the design air flow by the air flow indicated at the top of the appropriate Cool
-
ing Performance Table for the selected unit and efficiency, on
page 22
through
page 31.
Use
Table 2 on page 17
to determine the correction factors for total and
sensible capacities and compressor power.
4. Multiply the total and sensible capacities and compressor power from appropriate
Cooling Performance Table for design air and water conditions with the correction
factors above to determine the unit capacity adjusted for the airflow.
5. Determine if the cooling performance of this unit is acceptable. If not, repeat steps 2
through 4 above with a higher capacity unit.
6. If waterside economizer option is chosen, follow steps 3 and 4 above with appropri-
ate Waterside Economizer Cooling Performance Table on
page 32
.
7. If hot water heating option is required, follow steps 3 and 4 with appropriate Hot
Water data from Physical Data tables on
page 19–20
.
8. If electric heat option is required, obtain heating capacity based on electric heat ca-
pacity and unit voltage from Electric Heat Capacity Table on
page 68
.
9.
Select filtration types and efficiencies needed with corresponding air pressure drop
from
Table 30 on page 69 and
Table 31 on page 70
.
10. Select either airside economizer or inlet sound attenuating plenum, if required, with
corresponding air pressure drop from
Table 19 and Table 20 on page 57.
11. Select half or full outlet plenum, if required, with corresponding air pressure drop
from
Table 19 and Table 20 on page 57
.
12. With all options selected, add air pressure drops of all the components selected, in-
cluding evaporator coil, to external static pressure required to determine total static
pressure required for the supply air fan.
Summary of Contents for L-Series
Page 1: ...FORM 145 05 EG2 618 ENGINEERING GUIDE Water Cooled Self Contained Units L Series Vertical ...
Page 4: ...FORM 145 05 EG2 618 4 JOHNSON CONTROLS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 14: ...FORM 145 05 EG2 618 14 JOHNSON CONTROLS THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 35: ...FORM 145 05 EG2 618 JOHNSON CONTROLS 35 OVERVIEW OF SERVICE CLEARANCES LSWU025 040 MODELS ...
