22
Single Zone Extended Piping W
all Mounted Engineering Manual
'XHWRRXUSROLF\RIFRQWLQXRXVSURGXFWLQQRYDWLRQVRPHVSHFL¿FDWLRQVPD\FKDQJHZLWKRXWQRWL¿FDWLRQ
©
/*(OHFWURQLFV86$,QF(QJOHZRRG&OLIIV1-$OOULJKWVUHVHUYHG³/*´LVDUHJLVWHUHGWUDGHPDUNRI/*&RUS
Refrigerant Safety Standards
ASHRAE Standards 15-2010 and 34-2010 address refrigerant safety and the maximum allowable concentration of refrigerant in an occupied
space. Refrigerant will dissipate into the atmosphere, but a certain volume of air is required to safely dissipate the refrigerant. For R410A
refrigerant, the maximum allowable concentration of refrigerant is 26 lbs./1,000 cubic feet (Addendum L modified the RCL to 26) of occupied
spaces. Buildings with 24-hour occupancy are allowed half of that concentration.
If a single zone system develops a refrigerant leak, the entire refrigerant charge of the system will dump into the area where the leak occurs.
To meet ASHRAE Standards 15 and 34, the smallest room volume on the system must be calculated and compared to the maximum allow-
able concentration. Also consult state and local codes in regards to refrigerant safety.
REFRIGERANT SAFETY STANDARDS /
DEVICE CONNECTION LIMITATIONS
Device Connection Limitations
A single-zone system consists of one outdoor unit and
one indoor unit. One of the most critical elements of
a single-zone system is the refrigerant piping. If the
connection piping is not within allowable limits, there will
be reliability, performance, noise, and vibration issues.
The table below lists the pipe length limits that must be
followed in the design of a Single Zone Extended Piping
Wall Mount refrigerant pipe system. Refer to the figure
for maximum length and elevation of piping.
Figure 25: Single Zone Extended Piping System Layout.
Outdoor unit
Indoor unit
A
B
Outdoor unit
Indoor unit
A
B
Max Length = A
Max Elevation = B
Unit = Feet
Table 9: Single Zone Extended Piping Refrigerant Piping System Limitations.
Model Numbers
LS243HLV3
LS303HLV3
LS363HLV3
Pipe Sizes
Vapor
5/8 inches
5/8 inches
5/8 inches
Liquid
3/8 inches
3/8 inches
3/8 inches
Pipe Length
(ELF = Equivalent Length
of pipe in Feet)
Standard Piping Length
24.6
24.6
24.6
Piping Length with No Additional Refrigerant
24.6
24.6
24.6
Longest Total Equivalent Piping Length
164.0
164.0
164.0
Shortest Total Equivalent Piping Length
9.8
9.8
9.8
Distance between fittings and indoor units or outdoor units
LQFKHV
LQFKHV
LQFKHV
Elevation
(All Elevation Limitations
are Measured in Actual
Feet)
If outdoor unit is above indoor unit
98.4
98.4
98.4
If outdoor unit is below indoor unit
98.4
98.4
98.4
Additional Refrigerant Needed (oz./ft)
0.38
0.38
0.38