Refrigerant Charge Amount - Panasonic U-72MF1U9 Installation Instructions Manual

● Obtain liquid tubing size from Tables 1-3, 4, 5 and 9.
Main tubing
LA = ø5/8 (ft.) (Total capacity of indoor unit is 179,400 BTU/h)
LB = ø1/2 (ft.) (Total capacity of indoor unit is 131,600 BTU/h)
LC = ø3/8 (ft.) (Total capacity of indoor unit is 83,800 BTU/h)
Distribution joint tubing
Outdoor side A: ø3/8 (ft.)
Indoor side 1: ø3/8 (ft.)
● Obtain charge amount for each tubing size
Note1: The charge amounts per 1 ft. are different for each liquid tubing size.
ø5/8 (ft.) → LA
ø1/2 (ft.) → LB
ø3/8 (ft.) → LC + A – B + 1 – 4
Additional refrigerant charge amount is 418 oz.
Note 2: Necessary amount of additional refrigerant charge per outdoor unit (U-96MF1U9) is 42 oz. (See the Table 1-10-2.)
Note 1) Amount of additional charge per tubing length
Note 2) Amount of additional charge for outdoor unit
Total of additional refrigerant charge amount
Therefore, the total of additional refrigerant charge amount reaches 502 oz.
● Obtain overall refrigerant charge amount.
Overall refrigerant charge amount of the system indicates the calculated value shown above the addition al charge amount in
addition to the total of the refrigerant charge amount (shown in the Table 1-6) at the shipment of each outdoor unit.
Refrigerant charge amount at shipment:
Additional charge amount
Therefore, overall refrigerant charge amount of the system reaches 1334 oz.
Remark:
Be sure to include the values in Table 1-10-2 Necessary Amount of Refrigerant Charge Per Outdoor Unit.
Be sure to check the limit density for
CAUTION
the room in which the indoor unit is
installed.
The longest tubing length in this example
(LA = 131 ft.)
B: ø3/8 (ft.) (from outdoor unit connection tubing)
2: ø3/8 (ft.) 3: ø3/8 (ft.)
: 131 ft. × 1.99 oz/ft.
= 261 oz
: 16 ft. × 1.38 oz/ft.
= 22 oz
: 225 ft. × 0.602 oz/ft. = 135 oz
Total 418 oz
: 418 oz
: 84 oz (42+42)
: 502 oz
U-96MF1U9 : 416 oz
U-96MF1U9 : 416 oz
: 502 oz
Grand total : 1334 oz
19
4: ø3/8 (ft.) (from indoor unit connection tubing)