Interpretation #7201

Published July 17, 2013

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Original Request

Code Version
2010
Code
RESIDENT
Code Description
Residential
Chapter
14
Section
M1411.5
Topic
Pipe Insulation

Question

Is it the intent of the residential code to require pipe insulation meet R-4 value, but the Energy Code 403.3 to only require R-3. So is it true the most restrictive shall be enforced?

Answer Published 07/17/2013 at 4:23 PM

The answer is yes. the section in question specifically
addresses residential "vapor" lines while the referenced
section in the energy code addresses "fluids" above
105F or below 55F. The reference in the residential code is
applied to all residential vapor piping.

M1411.5 Insulation of refrigerant piping.
Piping and fittings for refrigerant vapor (suction) lines
shall be insulated with insulation having a thermal
resistivity of at least R-4 and having external surface
permeance not exceeding 0.05 perm [2.87 ng/(s × m2 ×
Pa)] when tested in accordance with ASTM E 96.

FBC EC 403.3 Mechanical system piping insulation
(Mandatory). Mechanical system piping capable of carrying
fluids above 105°F (41°C) or below 55°F (13°C) shall be
insulated to a minimum of R-3.

Commentary

None.