If the system charge is not listed in the above table, use the formulas below to calculate the
respective values:
• Minimum room area = system charge x 10.742
• Minimum total conditioned area = system charge x 14.458
• Minimum system airflow = system charge x 58.275
Mechanical ventilation
Table 3:
Item
number
Safety consideration
1 If installing the unit in a residence below the determined total conditioned area from
Room size requirements, then extra mechanical ventilation is required.
Refrigerant equipment checks
Table 4:
Item
number
Safety consideration
1 Where electrical components are being changed, they must be fit for the purpose
and to the correct specification. At all times, the manufacturer’s maintenance and
service guidelines must be followed. If in doubt, consult the manufacturer’s technical
department for assistance.
2 Apply the following checks to installations using flammable refrigerants:
• Ensure the actual refrigerant charge is in accordance with the room size within which
the refrigerant-containing parts are installed.
• Ensure the ventilation machinery and outlets are operating adequately and are not
obstructed.
• Ensure marking on the equipment continues to be visible and legible. Correct any
markings and signs that are illegible.
• Install refrigerating pipe or components in a position where they are unlikely to be
exposed to any substance that may corrode refrigerant-containing components,
unless the components are constructed of materials that are inherently resistant to
being corroded or are suitably protected against being corroded.
11Installation Manual: R-454B Outdoor Split-System Air Conditioner
Johnson Controls Ducted Systems
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