User Guide

56 l uponorengineering.com
Heat trace
Uponor approves the use of
heat-trace cables with Uponor
PEX products, provided
the product has automatic
thermostatic control capability
and the temperature does
not exceed the maximum
rating listed on the piping
(200ºF/93.3ºC). Wrap heat
tape around the piping and
secure the cable with plastic
cable ties, not tape; then
insulate with either closed-cell
or berglass pipe insulation
Thermal conductivity
Uponor PEX pipe has a very
low coefcient of thermal
conductivity: 0.219 Btu/
(h•ft•ºF). In comparison,
copper has a coefcient of
thermal conductivity between
173 and 231 Btu/(h•ft•ºF),
depending on wall thickness
(Type K, L or M). Therefore,
Uponor PEX piping does not
sweat like copper.
Uponor PEX has superior
insulating qualities when
compared to copper in the
same application. Even though
the difference in R-value is
relatively small, the higher
R-value of Uponor PEX piping
will always result in less
heat loss than with the same
nominal-size copper pipe.
When comparing samples
of the same thickness,
CPVC has a lower thermal
conductivity than Uponor PEX.
To represent these values in
the form of a pipe wall, we
must compare the conductivity
through a CTS SDR9 Uponor
PEX pipe wall to that of a CTS
SDR11 CPVC wall; SDR9
is 22 percent thicker than
SDR11.
When conductivity is applied
to the pipe wall thickness,
Uponor PEX is within two
percent of the thermal
resistance of CPVC.
Insulation
Uponor recommends
insulating all domestic hot-
water supply and return
piping as well as any hydronic
heating and cooling piping to
conserve energy and maintain
desired uid temperature.
Uponor also recommends
insulating any piping installed
in an unconditioned space or
poorly ventilated areas with
excessive moisture content.
Always comply with local and
energy codes.
Pre-insulated Uponor
AquaPEX piping
Pre-insulated Uponor
AquaPEX piping, which is
available in coils or straight
lengths, features closed-cell
polyethylene insulation to
make hot and cold potable-
water distribution systems
more efcient. The insulation
can also help meet energy-
code requirements; check
with local code authorities
regarding energy-code
requirements for specic
applications.
Pre-insulated Uponor
AquaPEX is available in the
following sizes:
• ½" to 2" with ½" thick
insulation
• ½" to 1¼" with 1" thick
insulation
• 1½" to 2" with 1½" thick
insulation
Note: When using Pre-
insulated Uponor AquaPEX
in direct-burial applications,
Uponor recommends using a
minimum 1" thick insulation
due to soil compression forces.
Pre-insulated Uponor AquaPEX with ½" insulation
Tubing size
Insulation
thickness
R-value
Heat loss at
70˚F Δ T
½" 0.6" (15mm) 3.9 7.4 Btu/(hr • ft)
¾" 0.6" (15mm) 3.6 9.0 Btu/(hr • ft)
1" 0.6" (15mm) 3.4 10.6 Btu/(hr • ft)
1¼" 0.6" (15mm) 3.3 12.1 Btu/(hr • ft)
1½" 0.6" (15mm) 3.2 13.6 Btu/(hr • ft)
2" 0.6" (15mm) 3.1 16.5 Btu/(hr • ft)
Pre-insulated Uponor AquaPEX with 1" insulation
Tubing size
Insulation
thickness
R-value
Heat loss at
70˚F Δ T
½" 1.0" (25mm) 7.5 6.3 Btu/(hr • ft)
¾" 1.1" (28mm) 7.9 7.1 Btu/(hr • ft)
1" 1.0" (25mm) 6.4 8.8 Btu/(hr • ft)
1¼" 1.0" (25mm) 6.1 10.0 Btu/(hr • ft)
Pre-insulated Uponor AquaPEX with 1½" insulation
Tubing size
Insulation
thickness
R-value
Heat loss at
70˚F Δ T
1½" 1.7" (42mm) 11.2 7.0 Btu/(hr • ft)
2" 1.6" (40mm) 9.9 8.6 Btu/(hr • ft)
Table 5-11: Pre-insulated Uponor AquaPEX with ½"
polyethylene insulation R-value/heat loss
Note: Pre-insulated Uponor AquaPEX consists of PEX-a pipe and closed cell,
crosslinked polyethylene insulation with a thermal conductivity of 0.25 Btu•in/
(hr•ft
2
•°F).
Table 5-12: Pre-insulated Uponor AquaPEX with 1"
polyethylene insulation R-value/heat loss
Table 5-13: Pre-insulated Uponor AquaPEX with 1½"
polyethylene insulation R-value/heat loss
Nominal
pipe size
R-value
½" 0.03
¾" 0.04
1" 0.052
1¼" 0.063
1½" 0.075
2" 0.098
2½" 0.122
3" 0.144
Table 5-9: SDR9 PEX R-value
Pipe Btu/(h•ft•ºF)
Copper 173-231
PEX-a 0.219
CPVC 0.079
Table 5-10: Thermal
conductivity of piping
materials