Table of Contents
Advertisement
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.
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.
Table 6: Single Zone Extended Pipe Refrigerant Piping System Limitations
Pipe Length
(ELF = Equivalent Length of
pipe in Feet)
Elevation
(All Elevation Limitations are
Measured in Actual Feet)
Additional Refrigerant Needed (oz/ft)
REFRIGERANT SAFETY STANDARDS /
DEVICE CONNECTION LIMITATIONS
Figure 19: Single Zone System Layout
Indoor unit
Longest total equivalent piping length
Shortest total equivalent piping length
If outdoor unit is above indoor unit
If outdoor unit is below indoor unit
©
Max Length = A
Max Elevation = B
A
B
Outdoor unit
LS243HLV
164.0
9.8
98.4
98.4
0.38
Unit = Feet
Outdoor unit
A
B
Indoor unit
LS303HLV
LS363HLV
164.0
164.0
9.8
9.8
98.4
98.4
98.4
98.4
0.38
0.38
21
Advertisement
Table of Contents
