SECTION 120.3 – REQUIREMENTS FOR PIPE INSULATION

Nonresidential, high-rise residential, and hotel/motel buildings shall comply with the applicable requirements of Sections 120.3(a) through 120.3(c).

(a) General Requirements.

The piping conditions listed below for space-conditioning and service water-heating systems with fluid normal operating temperatures listed in TABLE 120.3-A shall have at least the amount of insulation specified in Subsection (c):

1. Space Cooling Systems. All refrigerant suction, chilled water and brine fluid distribution systems.

2. Space Heating Systems. All refrierant steam, steam condensate and hot water fluid distribution systems.

A. Recirculating system piping, including the supply and return piping to the water heater.

B. The first 8 feet of hot and cold outlet piping including piping between a storage tank and a heat trap, for a nonrecirculating storage system.

Insulation conductivity shall be determined in accordance with ASTM C335 at the mean temperature listed in TABLE 120.3-A, and shall be rounded to the nearest 1/100 Btu-inch per hour per square foot per °F. Fluid distribution systems include all elements that are in series with the fluid flow, such as pipes, pumps, valves, strainers, coil u-bends, and air separators, but not including elements that are not in series with the fluid flow, such as expansion tanks, fill lines, chemical feeders, and drains.

(b) Insulation Protection.

Pipe Insulation shall be protected from damage, due to sunlight, moisture, equipment maintenance, and wind. Protection shall, at minimum, include the following:

1. Pipe insulation exposed to weather shall be protected by a cover suitable for outdoor service. The cover shall be water retardant and provide shielding from solar radiation that can cause degradation of the material. Adhesive tape shall not be used to provide this protection.

2. Pipe insulation covering chilled water piping and refrigerant suction piping located outside the conditioned space shall include, or be protected by, a Class I or Class II vapor retarder. All penetrations and joints shall be sealed.

3. Pipe insulation buried below grade must be installed in a water proof and non-crushable casing or sleeve.

1. For insulation with a conductivity in the range shown in TABLE 120.3-A for the applicable fluid temperature range, the insulation shall have the applicable minimum thickness or R-value shown in TABLE 120.3-A.

2. For insulation with a conductivity outside the range shown in TABLE 120.3-A for the applicable fluid temperature range, the insulation shall have a minimum R-value shown in TABLE 120.3-A or thickness as calculated with:

TABLE 120.3-A PIPE INSULATION THICKNESS

FLUID OPERATING TEMPERATURE RANGE
(°F)

INSULATION CONDUCTIVITY

NOMINAL PIPE DIAMETER (in inches)

1 to <1.5

1.5 to <4

4 to<8

8 and larger

Conductivity (in Btu-in/h per ft² °F)

Mean Rating Tempurature (°F)

INSULATION THICKNESS REQUIRED (in inches)

Space heating, Service Water Heating Systems (Steam, Steam Condensate, Refrigerant, Space Heating, Service Hot Water)

Minimum Pipe Insulation Required (Thickness in inches or R-value)

Above 350

0.32-0.34

250

Inches

4.5

5.0

R-value

R37

R41

R37

R27

R23

251-350

0.29-0.32

200

Inches

3.0

4.0

4.5

R-value

R24

R34

R35

R26

R22

201-250

0.27-0.30

150

Inches

2.5

3.0

R-value

R21

R20

R17.5

R17

R14.5

141-200

0.25-0.29

125

Inches

1.5

2.0

R-value

R11.5

R11

R14

R11

R10

105-140

0.22-0.28

100

Inches

1.0

1.5

R-value

R7.\

R12.5

R11

Nominal Pipe Diameter (in inches)

1 to <1.5

1.5 to <4

4 to<8

8 and larger

Space cooling systems (chilled water, refrigerant and brine)

Minimum Pipe Insulation Required (Thickness in inches or R-value)¹

40-60

0.21-0.27

Inches

Nonres 0.5

Res 0.75

Nonres 0.5

Res 0.75

1.0

R-value

Nonres R3

Res R6

Nonres R3

Res R5

Below 40

0.20-0.26

Inches

1.0

1.5

R-value

R8.5

R14

R12

R10

Footnote to TABLE 120.3-A:

1. These thickness are based on energy efficiency considerations only. Issues such as water vapor permeability or surface condensation sometimes require vapor retarders or additional insulation.

EXCEPTION 2 to Section 120.3: Piping that conveys fluids with a design operating temperature range between 60°F and 105°F.

EXCEPTION 3 to Section 120.3: Where the heat gain or heat loss to or from piping without insulation will not increase building source energy use.

EXCEPTION 4 to Section 120.3: Piping that penetrates framing members shall not be required to have pipe insulation for the distance of the framing penetration. Metal piping that penetrates metal framing shall use grommets, plugs, wrapping or other insulating material to assure that no contact is made with the metal framing.

NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8, and 25943, Public Resources Code

T	=	Minimum insulation thickness for material with conductivity K, inches.
PR	=	Pipe actual outside radius, inches.
t	=	Insulation thickness from TABLE 120.3-A, inches.
K	=	Conductivity of alternate material at the mean rating temperature indicated in TABLE 120.3-A for the applicable fluid temperature range, in Btu-inch per hour per square foot per °F.
k	=	The lower value of the conductivity range 'listed’ in Table 120.3-A for the applicable fluid temperature range, Btu-inch per hour per square foot per °F.