9
notE:
The entire refrigerant system must be fully evacuated
prior to system charging. Otherwise, moisture could be
present that could cause premature system damage and/
or failure.
• The refrigerant charge can be checked and adjusted through
the service ports provided. Use only line sets which have a
“Schrader” depression device present to actuate the valve.
• A filter dryer is provided with the unit and must be installed
in the liquid line of the system. If the installation replaces
a system with a filter dryer already present, the filter dryer
must be replaced with the one supplied with the unit. The
filter dryer must be installed in strict accordance with the
manufacturer’s installation instructions.
safety requirements for refrigerant charging
WarnInG:
r-410a is a colorless, non-flammable material that
is about 2.5 times denser than air. When leaked into
a living space, r-410a will displace air and settle
close to the floor. large amount of refrigerant in a
occupied space increases the risk of potential health
hazards including dizziness, loss of concentration,
or in very confined spaces, asphyxiation.
• The information in this safety section is based on ANSI
ashraE standard 15-2010 (standard 15) and ansI
ashraE standard 34-2010 (standard 34). according
to these standards, if local codes exist, the local codes
will take precedence.
• Standard 34 defines the maximum allowed concentration
of R-410A in an occupied space (without ventilation) as
25 lb./1000 ft^3
. The concentration of refrigerant in any
occupied space must not exceed this limit.
• First it is necessary to determine the occupied area that
has most potential for having the highest concentration of
refrigerant in the event of a leak prior to installing the unit.
To determine the Total Actual Occupied Volume (TAOV),
:
average height * average length * average Width
notE:
The volume of the plenum and return/supply air ducts
may also be included in the calculation. If the calculated
concentration for the refrigerant being used exceeds 25
lb./1000 ft^3, the system is not permitted.
Where the average height, length, and width is the actual
occupant dimensions. More detailed definitions are given in
Standard 15.
• Next, estimate the Total Required Occupied Volume (TROV)
needed for safe installation by using the following
TroV (ft^3) = Total refrigerant charge (lb.) x 40
The examples below were calculated assuming:
• 25’ single line length between well and compressor
sections (L1) and 6’ single line length between
compressor section and air handler (L2). For the 2
ton example, the well length is 200 ft and for the 5 ton
example, the well length is 400 ft. as shown in Table 4.
• The installed system is with an estimated R-410A charge,
without a machinery room, and the ceiling in the house
is 8 foot high.
2 ton EXaMPlE
To calculate TROV: 29.3 (lb.) of R-410A x 40 = 1172 ft^3
If the ceiling in the house is 8 foot high: 1172 ft^3
÷ 8 =
146 ft
2.
If the TAOV measurement is less than 146 ft
2,
use
any one of the 3 options below to install the unit.
5 ton EXaMPlE
To calculate TROV: 87 (lb.) of R-410A x 40 = 34802 ft^3
If the ceiling in the house is 8 foot high: 3480 ft^3
÷ 8 =
435 ft
2.
If the TAOV measurement is less than 435 ft
2,
use
any one of the 3 options below to install the unit.
option 1:
If the compressor section or air handler section are
installed in a small room, a small vent (4”x8”) can be installed
on the bottom of the return air duct (at the air handler) no more
than 6 inches from the floor.
option 2:
A 40 sq. inch square grill can be installed in the
door of the small room or between the adjoining wall of the
small room and a larger room no more than 6 inches from
the floor. The total volume of the small room and the larger
room must satisfy the TROV requirements.
option 3:
A 1” undercut is allowed on the bottom door of the
small room and an adjoining larger room as long as the total
volume of the small room and the larger room satisfy the
TROV requirements.
2 ton
3 ton
4 ton
5 ton
WEll
lEnGth
(Ft.)
r-410a
charGE
oz. (lBs)
WEll
lEnGth
(Ft.)
r-410a
charGE
oz. (lBs)
WEll
lEnGth
(Ft.)
r-410a
charGE
oz. (lBs)
WEll
lEnGth
(Ft.)
r-410a
charGE
oz. (lBs)
200
469 (29.3)
325
854 (53.4)
400
1,313 (82)
400
1,313 (82)
165
393 (24.6)
250
692 (43.3)
325
1,133 (70.8)
325
1,133 (70.8)
130
318 (19.9)
200
584 (36.5)
280
1,025 (64)
(x2) 250
1,553 (97)
notEs:
• The charge amounts shown above are for total system initial charge.
• Initial charge above assumes a 6 ft line set length between the compressor unit and the air handler (L1).
• Initial charge above assumes a 25 ft line set length between the compressor unit and the earth loop (L2).
• If line set lengths are different than the default lengths of 6 ft for L1 and 25 ft for L2, make adjustments according to
.
table 4. recommended Initial r410-a charges
