Product data

SELECTION PROCEDURE (with example)
I DETERMINE THE TYPE OF FAN COIL WHICH BEST
SUITS THE APPLICATION (REFER TO SYSTEMS IN-
DEX TABLE ON PAGE 21).
Duct-free split systems have 3 types of fan coils with over-
lapping capacities to choose from. Select the system type
which best meets the job conditions. This example will use
a 2-ton ceiling-suspended fan coil (assume wall space is
not available for a wall-mounted unit).
II DETERMINE COOLING LOAD REQUIREMENTS AT DE-
SIGN CONDITIONS.
Required Load Conditions:
Required cooling capacity (TCG) .........23,500 Btuh
Gross Sensible Heat Capacity (SHG) .....16,000 Btuh
Temperature Air Entering
Condensing Unit ..........................95F
Temperature Air Entering
Indoor Unit (EAT) ................82Fdb/68 F wb
db — dry bulb
wb — wet bulb
III SELECT SYSTEM THAT SATISFIES LOAD
REQUIREMENTS.
Enter the Systems Index table on page 21 at ceiling-
suspended system for 24,000 Btuh, and select the system
that best approximates cooling requirements. System in-
dex no. 6 with a nominal net capacity of 22,800 Btuh cool-
ing is the system selected. The system consists of a
538A024 outdoor unit matched with one 619C024 indoor
unit.
IV DETERMINE IF SYSTEM SELECTED SATISFIES
COOLING REQUIREMENTS.
Enter Cooling Capacities table on page 27 at high speed
(600 cfm) and 95 F outdoor entering air temperature (EAT,
air entering condenser). By interpolation, at 68 F EAT, the
system gross capacity is 23,680 Btuh cooling [(25,200 –
23,300) x (1/5) + 23,300], and 14,980 Btuh SHG (gross
sensible capacity). Adjust the SHG in accordance with
Note 2 of the Combinations Ratings table, using the cor-
rection factor for an 82 F ewb (entering air wet bulb), and
a 0.04 BF (bypass factor). The result is an adjusted SHG
of 16,141 Btuh. The total gross cooling capacity of 23,680
Btuh and the sensible heat capacity of 16,141 Btuh satisfy
stipulated cooling load requirements.
V DETERMINE NET COOLING CAPACITY AND SYSTEM
ENERGY EFFICIENCY RATIO.
Determine net cooling capacity (refer to Cooling Capacity
table for System 6 on page 27). Net total cooling capacity
must be interpolated as follows:
(24,700 - 22,800) x (1/5) + 22,800 = 23,180 Btuh
To determine the energy efficiency ratio (EER), system kW
must be interpolated from the Cooling Capacity table for
System 6 in the same manner:
(2.09 - 2.07) x (1/5) + 2.07 = 2.07 kW
Then calculate EER:
Net Cooling Capacity
EER =
kW x 1000
23,180
= 11.2 EER
2.07 x 1000
NOTE: The SEER (Seasonal Energy Efficiency Ratio)
CANNOT be calculated for this system. SEERs can only
be found as a direct result of testing at specified ARI con-
ditions. See ARI Capacities table on page 4.
VI DETERMINE THE RECOMMENDED LIQUID AND
VAPOR LINE SIZES.
Refer to Refrigerant Line Sizing section on page 42.
NOTE: With long-lines applications, it may be necessary
to adjust cooling capacity. See Long-Lines Applications
section on page 43 for more details.
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