Johnson Controls (H, Engineering Manual

Page: 66 / 124

OUTDOOR UNITS
2-44
TC-16006
2.13 Combinations of Indoor Units and Outdoor Units
Indoor Unit Type
Capacity (MBH)
6 8 12 15 18 24 30 36 48 72 96
Ducted
Ducted (High Static) (H,Y)IDH_B21S
Ducted (Medium Static) (H,Y)IDM_B21S
Ducted (Slim) (H,Y)IDS_B21S
Ducted (EconoFresh) (H,Y)IDM_B21E
DOAS (H,Y)DOA_B21S
Non-
Ducted
Ceiling-Mounted 4-Way Cassette (H,Y)IC4_B21S
Ceiling-Mounted 4-Way Cassette Mini (H,Y)ICM_B21S
Ceiling-Mounted 2-Way Cassette
(H,Y)IC2_B21S
Ceiling-Mounted 1-Way Cassette (H,Y)IC1_B21S
Wall-Mounted TIWM_B21S
Ceiling Suspended (H,Y)ICS_B21S
Floor Exposed (H,Y)IFE_B21S
Floor Concealed (H,Y)IFC_B21S
: Available
Table 2.1 Indoor Unit Type List
7KHQXPEHURILQGRRUXQLWVWKDWFDQEHFRQQHFWHGWRDQRXWGRRUXQLWLVGH¿QHGLQ7DEOH
Comply with the following conditions when selecting a system.
- A maximum and minimum total capacity against the nominal outdoor unit capacity can be obtained through
combination of indoor units.
Outdoor Unit
Capacity
(MBH)
Minimum Capacity at
Individual Operation
(MBH)
Maximum Number
of Connectable I.U.
Recommended
Number of
Connected I.U.
Connectable Indoor Unit
Capacity Ratio
*3)
Maximum
*2)
Minimum
72
6
*1)
15 10 130% 60%
96 16 10 110% 60%
144 31 18 130% 60%
168 30 18 110% 60%
192 33 18 110% 60%
288 50 32 110% 60%
*1) When the outdoor air temperature is 23
o
F (-5
o
C) or cooler during the outdoor unit cooling operation, the minimum
connectable indoor unit capacity is 18,000 Btu/h. A snow protection hood (optional part) should be installed.
*2) When the outdoor air temperature is 109
o
F (43
o
C) or warmer during the outdoor unit cooling operation, the maximum
connectable indoor unit capacity ratio is 100%.
*3) When the outdoor air temperature is lower than 14
o
F (-10
o
C) select the combination of indoor units and outdoor unit
as the total capacity of indoors not to exceed the capacity of outdoor unit.
Table 2.2 System Combination
NOTES:
1. The connectable indoor unit capacity ratio can be calculated as follows:
Connectable Indoor Unit Capacity Ratio = Total Indoor Unit Capacity / Total Outdoor Unit Capacity
2. For the system under which all the indoor units operate simultaneously, the total indoor unit capacity should be less
than the outdoor unit capacity. Otherwise, a decrease in operating performance and an increase in the operating limit
can result in an overload.
3. For the system under which all the indoor units do not operate simultaneously, the total indoor unit capacity is
available up to each maximum capacity ratio shown in the above Table 2.2.
4. A maximum number of connectable indoor units differs depending on the model, capacity, environment and
installation location of connected indoor units. Refer to the “Engineering Manual” for the selection.
5. When operating the outdoor unit in cold areas with temperatures of 14
o
F (-10
o
C), or under the high heating load
conditions, the total indoor unit capacity should be less than 100% against the outdoor unit capacity and the total
piping length should be less than 984.3ft (300m).
,IVRPHLQGRRUXQLWVVWDUWRSHUDWLQJVLPXOWDQHRXVO\DWDORZRXWGRRUDLUWHPSHUDWXUHWKHDLUÀRZPD\EHOHVVWKDQWKH
VHWWLQJDLUÀRZRQZLUHGFRQWUROOHUIRUPDLQWDLQLQJLQGRRUFRPIRUW
7KHDLUÀRZYROXPHIRULQGRRUXQLWVLVVHWKLJKHUWKDQWKDWIRULQGRRUXQRUPRUH
Make sure to select appropriate indoor units for installation where cold drafts may occur during heating operation.
If installing indoor units in such locations, refer to the recommended number of indoor units that can be connected.