CMC · California Mechanical Code

Infrared heaters — support, clearances and installation in commercial spaces

Q: Can I reduce clearances if the heater is listed for reduced clearances?

Yes. If a heater is listed for reduced clearances , install it according to its listing and manufacturer’s instructions rather than the generic numeric minimums in the CMC ( § 925.3(1) ) .

Q: Are hangers allowed to be plastic or wood?

No. The code requires hangers and brackets to be of noncombustible material for suspended infrared heaters ( § 925.2 ) .

Q: What if a heater is unlisted — who decides the clearance?

For unlisted heaters , clearances must be acceptable to the Authority Having Jurisdiction (AHJ) ; provide documentation and proposed clearances for approval, or comply with the code’s numeric minimums where applicable ( § 925.3(2) ) .

Commercial infrared heaters must be listed if ≤400,000 Btu/hr, be mounted on independent noncombustible supports, keep specified clearances to combustibles (or follow the heater’s listing), and unvented heaters require ventilation sized at 4 ft³/min per 1,000 Btu/h of total input; consult and document these provisions with your AHJ and the manufacturer’s instructions (CMC §§ 925.1–925.4) .

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Last reviewed: July 6, 2026

What the code requires — 2–4 sentences

Infrared heaters used in commercial spaces must be listed to the applicable standards when their input rating is 400,000 Btu/hr or less (§ 925.1) and be installed with supports, clearances and combustion/ventilation provisions required by the CMC. Suspended heaters must be fixed independently of gas and electrical lines, use noncombustible hangers, and include vibration isolation where needed (§ 925.2) . Clearances to combustibles follow the heater’s listing and installation instructions for listed heaters, and for unlisted heaters are set by the Authority Having Jurisdiction (AHJ) or by the numeric minimums in the code table; storage areas must post stacking-height signage to maintain required clearances (§ 925.3) . Where unvented infrared heaters are used, provide mechanical or natural supply and exhaust equal to 4 ft3/min per 1,000 Btu/h (0.38 m3/min per kW) of installed input; exhaust openings must be above the heaters (§ 925.4, § 925.4.1) .

The single most important rule: install listed infrared heaters per their listing and the manufacturer’s instructions; if a heater is unlisted, obtain clearances acceptable to the AHJ and provide required ventilation for unvented appliances (see § 925.3 and § 925.4) .

Requirements in detail

1) Application / listing

What’s required: Infrared heaters with an input rating of 400,000 Btu/hr (117 kW) or less must be listed in accordance with the ANSI/CSA standards cited in the code (§ 925.1) .
Practical effect: If the unit is listed, follow its listing and the manufacturer’s instructions for clearances, mounting, and installation; listed units may have reduced clearances indicated by the listing.

2) Support / mounting

Suspended-type infrared heaters must be fixed in position independent of gas and electric supply lines (do not hang the heater by its piping or wiring). Hangers and brackets must be noncombustible. Heaters subject to vibration require vibration-isolating hangers (§ 925.2) .
Key items to verify on plan and at inspection:
- Anchor/heavier support separate from flexible gas/electrical connections.
- Hanger material is noncombustible (steel, stainless, etc.).
- Provide isolators where ceiling-mounted fans, equipment, or other vibration sources exist.

3) Clearance to combustible materials

The hierarchy in the code:
1. Listed heaters — installed with clearances in accordance with their listing and the manufacturer’s installation instructions.
2. Unlisted heaters — clearances must be acceptable to the AHJ; the code provides minimum clearances for unlisted units and for flame heights (see table) (§ 925.3(1)–(2)) .
3. Storage locations — where combustibles are stored, signs must be posted specifying the maximum permissible stacking height to maintain required clearances (§ 925.3(3)) .
Decision-relevant dimensions (from the code table in § 925.3). Measurements are from the nearest portion of the burner head.

Flame height above burner head (in)	Minimum horizontal clearance from combustibles (ft)	Minimum vertical clearance from combustibles (ft)	Code Reference
12	2	6	§ 925.3
18	3	8	§ 925.3
24	3	10	§ 925.3
30	4	12	§ 925.3

Notes:
- Convert units as needed (1 in = 25.4 mm; 1 ft = 304.8 mm) — that conversion is noted in the code table. The table values are minimums for unlisted appliances where applicable; listed appliances follow their listing/manufacturer instructions (§ 925.3) .

4) Combustion and ventilation air

For unvented infrared heaters, provide natural or mechanical supply and exhaust at a rate of 4 ft³/min per 1,000 Btu/h (0.38 m³/min per kW) of installed heater input (total of installed heaters) (§ 925.4) .
Exhaust openings intended to remove combustion products must be above the level of the heaters (§ 925.4.1) .
Practical checklist:
- Sum installed input (Btu/h) for all unvented infrared heaters in the space.
- Multiply installed Btu/h (per 1000) × 4 ft³/min to size supply and exhaust.
- Confirm exhaust openings are physically above heater level and that air paths do not short-circuit.

Exceptions & special cases

If a heater is listed for reduced clearances, install it per that listing and the manufacturer’s instructions rather than the numeric minimums in the table — listed appliance requirements take precedence (§ 925.3(1)) .
Unlisted heaters are not forbidden, but their clearances must be acceptable to the AHJ; that often requires submitting installation details to the local building department for approval (§ 925.3(2)) .
Storage areas under heaters require posted signage specifying maximum stacking height to ensure required clearances are maintained (§ 925.3(3)) .
Suspended low-intensity infrared tube heaters and gas connectors are covered elsewhere in the code (see related provisions) and have additional connector/support requirements — check those referenced sections for tube-type heaters and connector listing requirements.

Common mistakes

Hanging the heater from its gas or electrical conduit/connector instead of using independent structural supports (violates § 925.2) .
Using combustible hangers or brackets — the code requires noncombustible hangers (§ 925.2) .
Assuming “listed” means no clearance verification — listings and manufacturer instructions still govern clearances and may specify different (often reduced) clearances (§ 925.3(1)) .
Failing to size ventilation when installing unvented infrared heaters; forgetting the 4 ft³/min per 1,000 Btu/h rule leads to indoor air-quality and combustion-safety issues (§ 925.4) .
Installing exhaust openings at or below heater level instead of above heater level (violates § 925.4.1) .

Worked example — application of the rule with numbers

Scenario: A commercial warehouse will have two unvented infrared gas heaters. Each heater has an input rating of 100,000 Btu/h. The heater’s flame height is 18 inches above the burner head.

Listing check: Each heater is unvented; assume they are unlisted for the clearance example (if listed, follow listing). The total installed input = 100,000 + 100,000 = 200,000 Btu/h (total) — see § 925.1 and § 925.4 .
Ventilation: Required supply and exhaust = 4 ft³/min per 1,000 Btu/h × (200,000 / 1,000) = 4 × 200 = 800 ft³/min. Provide mechanical or natural means to supply and exhaust this rate and ensure exhaust openings are above heater level (§ 925.4, § 925.4.1) .
Clearance from combustibles (using the table for 18 in flame height): Minimum horizontal clearance = 3 ft, minimum vertical clearance = 8 ft measured from the nearest portion of the burner head — ensure aisle/stacking and shelving locations comply and post stacking-height signage in storage areas per § 925.3 .
Support: Each suspended heater must be fixed independently of gas and electrical supply lines, supported by noncombustible hangers and fitted with vibration isolators if needed (§ 925.2) .

Apply these steps in plan reviews and inspections: confirm heater input totals, ventilation calculations, physical clearances, posted signs where combustibles are stored, and independent noncombustible supports.

Related provisions

§ 925.5 — Installation in commercial garages and aircraft hangars (listed overhead heaters in these occupancies) .
§ 925.6 — Electric radiant heaters must comply with UL 2021 and the manufacturer’s installation instructions (electric radiant-specific rules) .
§ 1312.2 — Suspended low-intensity infrared tube heaters: connector and installation requirements (fuel-gas connector listing and use) .
Sections on unit heaters and room heaters (e.g., § 916.2, § 915.3) provide related support and clearance concepts for different heater types; consult those for unit- or room-type heater installations .

Code references

Grounded in the retrieved California Mechanical Code — click a citation to read the verbatim passage:

CMC § 923.5 High relevance — show source text
923.5 Appliance Pressure Regulators. Where an appliance pressure regulator is not supplied with an illuminating appliance and the service line is not equipped with a service pressure regulator, an appliance pressure regulator shall be installed in the line serving one or more illuminating appliances. [NFPA 54:10.14.5]

924.0 Incinerators and Crematories.

924.1 Field Constructed Commercial-Industrial

Incinerators. Field constructed commercial-industrial incin erators shall be constructed and installed in accordance with

NFPA 82.

924.2 Factory-Built Commercial Crematories. Factorybuilt commercial incinerators and crematories shall comply with UL 2790 and installed in accordance with the manufac turer’s installation instructions.

924.3 Residential Incinerators. Residential incinerators shall comply with UL 791 and installed in accordance with the manufacturer’s installation instructions.

925.0 Infrared Heaters.

925.1 Application. Infrared heaters having an input rating of 400 000 Btu/hr (117 kW) or less shall be listed in accordance with ANSI Z83.19/CSA 2.35 or ANSI Z83.20/CSA 2.34. [NFPA 54:10.16.1]

925.2 Support. Suspended-type infrared heaters shall be fixed in position independent of gas and electric supply lines. Hangers and brackets shall be of noncombustible material. Heaters subject to vibration shall be provided with vibrationisolating hangers. [NFPA 54:10.16.2]

925.3 Clearance. The installation of infrared heaters shall comply with the following clearance requirements:

(1) Listed heaters shall be installed with clearances from combustible material in accordance with their listing and the manufacturer’s installation instructions.

(2) Unlisted heaters shall be installed in accordance with clearances from combustible material acceptable to the Authority Having Jurisdiction.

(3) In locations used for the storage of combustible materials, signs shall be posted to specify the maximum per

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FLAME HEIGHT ABOVE
BURNER HEAD
(inches) MINIMUM CLEARANCE FROM
COMBUSTIBLE MATERIAL
(feet)* Col3

FLAME HEIGHT ABOVE
BURNER HEAD
(inches) HORIZONTAL VERTICAL

12 2 6

18 3 8

24 3 10

30 4 12

For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm
- Measured from the nearest portion of the burner head.
2025 CALIFORNIA MECHANICAL CODE 211

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INSTALLATION OF SPECIFIC APPLIANCES

927.2 Clearance. Refrigerators shall be provided with clearances for ventilation at the top and back in accordance with the manufacturer’s instructions. Where such instructions are
CMC § 925.3 High relevance — show source text
925.3 Clearance. The installation of infrared heaters shall comply with the following clearance requirements:

(1) Listed heaters shall be installed with clearances from combustible material in accordance with their listing and the manufacturer’s installation instructions.

(2) Unlisted heaters shall be installed in accordance with clearances from combustible material acceptable to the Authority Having Jurisdiction.

(3) In locations used for the storage of combustible materials, signs shall be posted to specify the maximum per

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FLAME HEIGHT ABOVE
BURNER HEAD
(inches) MINIMUM CLEARANCE FROM
COMBUSTIBLE MATERIAL
(feet)* Col3

FLAME HEIGHT ABOVE
BURNER HEAD
(inches) HORIZONTAL VERTICAL

12 2 6

18 3 8

24 3 10

30 4 12

For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm
- Measured from the nearest portion of the burner head.
2025 CALIFORNIA MECHANICAL CODE 211

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INSTALLATION OF SPECIFIC APPLIANCES

927.2 Clearance. Refrigerators shall be provided with clearances for ventilation at the top and back in accordance with the manufacturer’s instructions. Where such instructions are

not available, at least 2 inches (51 mm) shall be provided between the back of the refrigerator and the wall at least 12 inches (305 mm) above the top. [NFPA 54:10.20.2]

927.3 Venting or Ventilating Kits Approved for Use with a Refrigerator. Where an accessory kit is used for conveying air for burner combustion or unit cooling to the refrigerator from areas outside the room in which it is located, or for conveying combustion products diluted with air containing waste heat from the refrigerator to areas outside the room in which it is located, the kit shall be installed in accordance with the refrigerator manufacturer’s instructions. [NFPA 54:10.20.3]

928.0 Gas-Fired Toilets.

928.1 Clearance. A listed gas-fired toilet shall be installed in accordance with its listing and the manufacturer’s installation instructions, provided that the clearance shall be such to afford ready accessibility for use, cleanout, and necessary servicing. {NFPA 54:10.23.1}

928.2 Installation on Combustible Floors. Listed gasfired toilets installed on combustible floors shall be listed for

such installation. [NFPA 54:10.23.2]

928.3 Vents. Vents or vent connectors that are capable of being contacted during casual use of the room in which the toilet is installed shall be protected or shielded to prevent such contact. [NFPA 54:10.23.3]

929.0 Appliances for Installation in Manufactured Housing. [Not adopted by HCD]
CMC § 923.0 High relevance — show source text
923.0 Illuminating Appliances. . . . . . . . . 211

923.1 Clearances for Listed Appliances. . 211

923.2 Clearances for Unlisted

Appliances . . . . . . . . . . . . . . . . . . 211

Table 923.2.1 Clearances for Unlisted Outdoor

Open-Flame Illuminating Appliances . . . . . . . . . . . . . . . . . . 211

923.3 Mounting on Buildings . . . . . . . . . 211

923.4 Mounting on Posts . . . . . . . . . . . . 211

923.5 Appliance Pressure Regulators . . . 211

924.0 Incinerators and Crematories . . . . 211

924.1 Field Constructed Commercial Industrial Incinerators . . . . . . . . . . 211

924.2 Factory-Built Commercial Crematories . . . . . . . . . . . . . . . . . 211

924.3 Residential Incinerators . . . . . . . . 211

925.0 Infrared Heaters . . . . . . . . . . . . . . 211

925.1 Application . . . . . . . . . . . . . . . . . . 211

925.2 Support . . . . . . . . . . . . . . . . . . . . . 211

925.3 Clearance . . . . . . . . . . . . . . . . . . . 211

925.4 Combustion and Ventilation Air . . . 212

925.5 Installation in Commercial

Garages and Aircraft Hangars . . . 212

925.6 Electric Radiant Heaters. . . . . . . . 212

926.0 Pool Heaters. . . . . . . . . . . . . . . . . 212

926.1 Application . . . . . . . . . . . . . . . . . . 212

926.2 Location . . . . . . . . . . . . . . . . . . . . 212

926.3 Clearance . . . . . . . . . . . . . . . . . . . 212

926.4 Temperature or PressureLimiting Devices . . . . . . . . . . . . . . 212

926.5 Bypass Valves . . . . . . . . . . . . . . . 212

926.6 Venting . . . . . . . . . . . . . . . . . . . . . 212

927.0 Refrigerators. . . . . . . . . . . . . . . . . 212

927.1 Application . . . . . . . . . . . . . . . . . . 212

927.2 Clearance . . . . . . . . . . . . . . . . . . . 212

927.3 Venting or Ventilating Kits Approved for Use with a Refrigerator. . . . . . . . . . . . . . . . . . 212

928.0 Gas-Fired Toilets . . . . . . . . . . . . . 212

928.1 Clearance . . . . . . . . . . . . . . . . . . . 212

928.2 Installation on Combustible
CMC § 915.3.3 High relevance — show source text
(2) Radiating type room heaters other than those of the circulating type described in Section 915.3.3(1) shall have clearance at sides and rear of not less than 18 inches (457 mm), except that heaters that make use of metal, asbestos, or ceramic material to direct radiation to the front of the heater shall have a clearance of 36 inches (914 mm) in front and, where constructed with a double back of metal or ceramic, shall be permitted to be installed with a clearance of 18 inches (457 mm) at sides and 12 inches (305 mm) at rear. Combustible floors under unlisted room heaters shall be protected in an approved manner.

915.3.4 Wall-Mounted Room Heaters. Wall mounted room heaters shall not be installed in or attached

to walls of combustible material unless listed for such installation. [NFPA 54:10.21.4]

915.4 Solid-Fuel Type Room Heaters. Solid-fuel type room heaters shall comply with UL 1482.

916.0 Unit Heaters.

916.1 Application. Unit heaters shall be listed in accordance with ANSI Z83.8/CSA 2.6 and installed in accordance with the manufacturer’s installation instructions. [NFPA 54:10.24.1]

916.2 Support. Suspended-type unit heaters shall be safely and adequately supported, with due consideration given to their weight and vibration characteristics. Hangers and brackets shall be of noncombustible material. [NFPA 54:10.24.2]

916.3 Clearance for Suspended-Type Unit Heaters. Suspended-type unit heaters shall comply with the following requirements:

(1) Unit heaters shall be installed with clearances from combustible material of not less than 18 inches (457 mm) at the sides, 12 inches (305 mm) at the bottom, and 6 inches (152 mm) above the top where the unit heater has an internal draft hood, or 1 inch (25.4 mm) above the top of the sloping side of a vertical draft hood. A unit heater listed for reduced clearances shall be installed in accordance with its listing and the manufacturer’s installation instructions.

(2) Clearances for servicing shall be in accordance with the manufacturer’s installation instructions. {NFPA 54:10.24.3}

916.3.1 Floor-Mounted-Type Unit Heaters. Floormounted-type unit heaters shall comply with the following requirements:

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208 2025 CALIFORNIA MECHANICAL CODE

), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

INSTALLATION OF SPECIFIC APPLIANCES

permitted where protected in accordance with Table 303.10.1.

[NFPA 54:10.11.5] 917.6 Use with Casters. Floor-mounted appliances with casters shall be listed for such construction and shall be

installed in accordance with the manufacturer’s installation instructions for limiting the movement of the appliance to prevent strain on the connection. [NFPA 54:10.11.6]

917.7 Level Installation. Floor-mounted food service appliances shall be installed level on a firm foundation.

[NFPA 54:10.11.7]

FLAME HEIGHT ABOVE BURNER HEAD (inches)	MINIMUM CLEARANCE FROM COMBUSTIBLE MATERIAL (feet)*	Col3
FLAME HEIGHT ABOVE BURNER HEAD (inches)	HORIZONTAL	VERTICAL
12	2	6
18	3	8
24	3	10
30	4	12

FLAME HEIGHT ABOVE BURNER HEAD (inches)	MINIMUM CLEARANCE FROM COMBUSTIBLE MATERIAL (feet)*	Col3
FLAME HEIGHT ABOVE BURNER HEAD (inches)	HORIZONTAL	VERTICAL
12	2	6
18	3	8
24	3	10
30	4	12

CMC § 12-7 High relevance — show source text

|143|180|2|386| |2:50|1|912|276|110|4|602|1|045|153|390|2|556|

26 2025 CALIFORNIA REFERENCED STANDARDS CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

FIRE-RESISTIVE STANDARDS

TABLE 12-7-3A—STANDARD TIME-TEMPERATURE CURVE FOR CONTROL OF FIRE TESTS—continued	Col2	Col3	Col4	Col5	Col6	Col7	Col8	Col9	Col10	Col11	Col12	Col13
TIME	AREA ABOVE 68°F BASE	AREA ABOVE 68°F BASE	AREA ABOVE 68°F BASE	AREA ABOVE 68°F BASE	AREA ABOVE 68°F BASE	AREA ABOVE 68°F BASE	AREA ABOVE 20°C BASE	AREA ABOVE 20°C BASE	AREA ABOVE 20°C BASE	AREA ABOVE 20°C BASE	AREA ABOVE 20°C BASE	AREA ABOVE 20°C BASE
TIME	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE	TEMPERATURE
hr.: min.	°Fahr.	°Fahr.	°Fahr. min.	°Fahr. min.	°Fahr. hr.	°Fahr. hr.	°Cent.	°Cent.	°Cent. min.	°Cent. min.	°Cent. hr.	°Cent. hr.
3:00	1	925	294	610	4	910	1	052	163	670	2	728
3:10	1	938	313	250	5	221	1	059	174	030	2	900
3:20	1	950	332	000	5	533	1	066	184	450	3	074
3:30	1	962	350	890	5	848	1	072	194	940	3	249
3:40	1	975	369	890	6	165	1	079	205	500	3	425
3:50	1	988	389	030	6	48

California Mechanical Code Medium relevance — show source text

53
47|195
134
107
92
82|276
190
152
131
116|590
406
326
279
247|1060
730
586
502
445|1680
1150
925
791
701|3490
2400
1930
1650
1460| |60
70
80
90
100|60
70
80
90
100|10
NA
NA
NA
NA|21
19
18
17
16|42
39
36
34
32|74
68
63
59
56|105
96
90
84
79|224
206
192
180
170|403
371
345
324
306|635
585
544
510
482|1320
1220
1130
1060
1000| |125
150
175
200
250|125
150
175
200
250|NA
NA
NA
NA
NA|14
13
12
11
NA|28
26
24
22
20|50
45
41
39
34|70
64
59
55
48|151
136
125
117
103|271
245
226
210
1
CMC § 919.0 Medium relevance — show source text
919.0 Household Cooking Appliances. . . 209

919.1 Application . . . . . . . . . . . . . . . . . . 209

919.2 Electric Household Cooking Appliances . . . . . . . . . . . . . . . . . . 209

919.3 Gas-Fired Household Cooking Appliances . . . . . . . . . . . . . . . . . . 209

919.4 Floor-Mounted Units . . . . . . . . . . . 210

919.5 Built-In Units . . . . . . . . . . . . . . . . . 210

919.6 Level Installation. . . . . . . . . . . . . . 210

920.0 Cooking Appliance Listings . . . . . 210

920.1 Commercial Electric Ranges . . . . 210

920.2 Commercial Wood-Fired

Baking Ovens . . . . . . . . . . . . . . . . 210

920.3 Oil-Burning Ranges . . . . . . . . . . . 210

921.0 Open-Top Broiler Units. . . . . . . . . 210

921.1 Application . . . . . . . . . . . . . . . . . . 210

921.2 Protection Above Domestic Units. . 210

2025 CALIFORNIA MECHANICAL CODE

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TABLE OF CONTENTS

921.3 Commercial Units . . . . . . . . . . . . . 210

922.0 Outdoor Cooking Appliances . . . . 210

922.1 Application . . . . . . . . . . . . . . . . . . 210

923.0 Illuminating Appliances. . . . . . . . . 211

923.1 Clearances for Listed Appliances. . 211

923.2 Clearances for Unlisted

Appliances . . . . . . . . . . . . . . . . . . 211

Table 923.2.1 Clearances for Unlisted Outdoor

Open-Flame Illuminating Appliances . . . . . . . . . . . . . . . . . . 211

923.3 Mounting on Buildings . . . . . . . . . 211

923.4 Mounting on Posts . . . . . . . . . . . . 211

923.5 Appliance Pressure Regulators . . . 211

924.0 Incinerators and Crematories . . . . 211

924.1 Field Constructed Commercial Industrial Incinerators . . . . . . . . . . 211

924.2 Factory-Built Commercial Crematories . . . . . . . . . . . . . . . . . 211

924.3 Residential Incinerators . . . . . . . . 211

925.0 Infrared Heaters . . . . . . . . . . . . . . 211

925.1 Application . . . . . . . . . . . . . . . . . . 211

925.2 Support . . . . . . . . . . . . . . . . . . . . . 211

925.3 Clearance . . . . . . . . . . . . . . . . . . . 211

925.4 Combustion and Ventilation Air . . . 212

925.5 Installation in Commercial
California Mechanical Code Medium relevance — show source text
to farthest sprinkler (feet)**|Allowable length of pipe from service valve to farthest sprinkler (feet)|Allowable length of pipe from service valve to farthest sprinkler (feet)|Allowable length of pipe from service valve to farthest sprinkler (feet)| |8|1|314|418|523|628|732|837|941|1,046|1,151|1,255| |9|1|252|336|421|505|589|673|757|841|925|1,009| |10|1|208|277|346|415|485|554|623|692|761|831| |11|1|174|232|290|348|406|464|522|580|638|696| |12|1|148|198|247|296|346|395|445|494|543|593| |13|1|128|170|213|256|298|341|383|426|469|511| |14|1|111|149|186|223|260|297|334|371|409|446| |15|1|98|131|163|196|229|262|294|327|360|392| |16|1|87|116|145|174|203|232|261|290|319|348| |17|1|78|104|130|156|182|208|233|259|285|311| |18|1|70|93|117|140|163|187|210|233|257|280| |19|1|63|84|106|127|148|169|190|211|232|253| |20|1|58|77|96|115|134|154|173|192|211|230| |21|1|53|70|88|105|123|140|158|175|193|211| |22|1|48|64|80|97|113|129|145|161|177|193| |23|1|44|59|74|89|104|119|133|148|163|178| |24|1|41|55|69|82|96|110|123|137|15
CMC § 11.15 Medium relevance — show source text
ADMINISTRATION

Building:
1. One-story detached accessory structures used as tool and storage sheds, playhouses and similar uses, provided that the floor area does not exceed than 120 square feet (11.15 m [2] ). It is permissible that these structures still be regulated by Section 710A, despite exemption from permit.
2. Fences, other than swimming pool barriers, not over 7 feet (2134 mm) high.
3. Oil derricks.
4. Retaining walls that are not over 4 feet (1219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II or IIIA liquids.
5. Water tanks supported directly on grade if the capacity is not greater than 5,000 gallons (18 925 L) and the ratio of height to diameter or width is not greater than 2:1.
6. Sidewalks and driveways not more than 30 inches (762 mm) above adjacent grade, and not over any basement or story below and are not part of an accessible route.
7. Painting, papering, tiling, carpeting, cabinets, countertops and similar finish work.
8. Temporary motion picture, television and theater stage sets and scenery.
9. Prefabricated swimming pools accessory to a Group R-3 occupancy that are less than 24 inches (610 mm) deep, are not greater than 5,000 gallons (18 925 L) and are installed entirely above ground.
10. Shade cloth structures constructed for nursery or agricultural purposes, not including service systems.
11. Swings and other playground equipment accessory to detached one- and two-family dwellings.
12. Window awnings in Group R-3 and U occupancies, supported by an exterior wall that do not project more than 54 inches (1372 mm) from the exterior wall and do not require additional support.
13. Nonfixed and movable fixtures, cases, racks, counters and partitions not over 5 feet 9 inches (1753 mm) in height.
Electrical:
1. Repairs and maintenance: Minor repair work, including the replacement of lamps or the connection of approved portable electrical equipment to approved permanently installed receptacles.
2. Radio and television transmitting stations: The provisions of this code shall not apply to electrical equipment used for radio and television transmissions, but do apply to equipment and wiring for a power supply and the installations of towers and antennas.
3. Temporary testing systems: A permit shall not be required for the installation of any temporary system required for the testing or servicing of electrical equipment or apparatus.
Gas:
1. Portable heating appliance.
2. Replacement of any minor part that does not alter approval of equipment or make such equipment unsafe.
Mechanical:
1. Portable heating appliance.
2. Portable ventilation equipment.
3. Portable cooling unit.
4. Steam, hot or chilled water piping within any heating or cooling equipment regulated by this code.
5. Replacement of any part that does not alter its approval or make it unsafe.
6. Portable evaporative cooler.
7. Self-contained refrigeration system containing 10 pounds (4.54 kg) or less of refrigerant and actuated by motors of 1 horsepower (0.75 kW) or less.
California Mechanical Code Medium relevance — show source text
Clearance
to Obstruction
4” Min. Clearance
Required. (See Note 1
and Note 6)
Bolts
”
in.
15”
28”
Min.
Location of
Terminating
Pull
Section
(See
Note 1)
30”
Load Section Only–.
Not a Utility Service
Termination Section.
75” M
Heig
Oute
Enclo|Blank Panel (Sealable)
Hinge
Meter Panels
Hinge

Only for Low Profile
10” Min. Clearance
to Obstruction
4” Min. Clearance
Required. (See Note 1
and Note 6)
Bolts
”
in.
15”
28”
Min.
Location of
Terminating
Pull
Section
(See
Note 1)
30”
Load Section Only–.
Not a Utility Service
Termination Section.
75” M
Heig
Oute
Enclo|Hinge
Meter Panels
Bolts|Hinge
Meter Panels
Bolts|Hinge
Meter Panels
Bolts| |Blank Panel (Sealable)
Hinge
Meter Panels
Hinge

Only for Low Profile
10” Min. Clearance
to Obstruction
4” Min. Clearance
Required. (See Note 1
and Note 6)
Bolts
”
in.
15”
28”
Min.
Location of
Terminating
Pull
Section
(See
Note 1)
30”
Load Section Only–.
Not a Utility Service
Termination Section.
75” M
Heig
Oute
Enclo|Blank Panel (Sealable)
Hinge
Meter Panels
Hinge

Only for Low Profile
10” Min. Clearance
to Obstruction
4” Min. Clearance
Required. (See Note 1
and Note 6)
Bolts
”
in.
15”
28”
Min.
Location of
Terminating
Pull
Section
(See
Note 1)
30”
Load Section Only–.
Not a Utility Service
Termination Section.
75” M
Heig
Oute
Enclo|Hinge
10” Min. Clearance
|Hinge
10” Min. Clearance
|Hinge
10” Min. Clearance
| |”
in||||| |”
in||to Obstruction
4” Min. Clearance
Required. (See Note 1
and Note 6)
Load Section Only–.
Not a Utility Service
Termination Section.|to Obstruction
4” Min. Clearance
Required. (See Note 1
and Note 6)
Load Section Only–.
Not a Utility Service
Termination Section.|to Obstruction
4” Min.
CMC § 914.5 Medium relevance — show source text
914.5 Air Supply . . . . . . . . . . . . . . . . . . . 207

914.6 Atmospheric Vents, Gas Reliefs, or Bleeds . . . . . . . . . . . . . 207

914.7 Relief Openings . . . . . . . . . . . . . . 207

914.8 Purging . . . . . . . . . . . . . . . . . . . . . 207

915.0 Room Heaters . . . . . . . . . . . . . . . 207

915.1 Application . . . . . . . . . . . . . . . . . . 207

915.2 Electric Room Heaters . . . . . . . . . 207

915.3 Gas-Fired Room Heaters . . . . . . . 207

xxxvi

915.4 Solid-Fuel Type Room Heaters . . 208

916.0 Unit Heaters . . . . . . . . . . . . . . . . . 208

916.1 Application . . . . . . . . . . . . . . . . . . 208

916.2 Support . . . . . . . . . . . . . . . . . . . . 208

916.3 Clearance for Suspended-Type Unit Heaters . . . . . . . . . . . . . . . . . 208

916.4 Combustion and Circulating Air. . . 208

916.5 Ductwork. . . . . . . . . . . . . . . . . . . . 208

916.6 Installation in Commercial

Garages and Aircraft Hangars . . . 208

916.7 Oil-Fired Unit Heaters. . . . . . . . . . 208

917.0 Food Service Appliance, FloorMounted . . . . . . . . . . . . . . . . . . . . 208

917.1 Application . . . . . . . . . . . . . . . . . . 208

917.2 Clearance for Listed Appliances. . . 208

917.3 Mounting on Combustible Floors . . . . . . . . . . . . . . . . . . . . . . 208

917.4 Installation on Noncombustible

Floors . . . . . . . . . . . . . . . . . . . . . . 209

917.5 Combustible Material

Adjacent to Cooking Top . . . . . . . 209

917.6 Use with Casters . . . . . . . . . . . . . 209

917.7 Level Installation. . . . . . . . . . . . . . 209

917.8 Ventilation. . . . . . . . . . . . . . . . . . . 209

918.0 Food Service Appliances, Counter Appliances . . . . . . . . . . . 209

918.1 Application . . . . . . . . . . . . . . . . . . 209

918.2 Vertical Clearance . . . . . . . . . . . . 209

918.3 Clearance for Listed Appliances. . . 209

918.4 Clearance for Unlisted

Appliances . . . . . . . . . . . . . . . . . . 209

919.0 Household Cooking Appliances. . . 209
CMC § 929.1 Medium relevance — show source text
929.1 General. [Not adopted by HCD] Appliances installed in manufactured housing after the initial sale shall be listed for installation in manufactured housing, or approved, and shall be installed in accordance with the requirements of this code and the manufacturer’s installation instructions.

Appliances installed in the living space of manufactured housing shall be in accordance with the requirements of Section 701.0. [NFPA 54:10.28]

930.0 Small Ceramic Kilns.

930.1 General. The provisions of this section apply to kilns used for ceramics that have a maximum interior volume of 20 cubic feet (0.57 m [3] ) and are used for hobby or noncommercial purposes.

930.2 Installation. Kilns shall be installed in accordance with the manufacturer’s installation instructions and the provisions of this code.

930.3 Fuel-Gas Controls. Fuel-gas controls shall comply with Section 306.0 and Section 902.4. Standing pilots shall not be used with gas-fired kilns. 930.4 Electrical Equipment. All electrical equipment used as part of, or in connection with, the installation of a kiln

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missible stacking height to maintain required clearances from the heater to the combustibles. {NFPA 54:10.16.3}

925.4 Combustion and Ventilation Air. Where unvented

infrared heaters are used, natural or mechanical means shall be provided to supply and exhaust at least 4 ft [3] /min/1000 Btu/h (0.38 m [3] /min/kW) input of installed heaters. [NFPA 54:10.16.4.1]

925.4.1 Exhaust Openings. Exhaust openings for removing flue products shall be above the level of the heaters. [NFPA 54:10.16.4.2]

925.5 Installation in Commercial Garages and Air- craft Hangars. Overhead heaters installed in garages for more than three motor vehicles or in aircraft hangars shall be listed and shall be installed in accordance with Section 303.11 and Section 303.12. [NFPA 54:10.16.5]

925.6 Electric Radiant Heaters. Electric radiant heaters shall comply with UL 2021 and installed in accordance with the manufacturer’s installation instructions.

926.0 Pool Heaters.

926.1 Application. Pool heaters shall be listed in accordance with CSA/ANSI Z21.56/CSA 4.7. [NFPA 54:10.19.1]

926.2 Location. A pool heater shall be located or protected so as to minimize accidental contact of hot surfaces by persons. [NFPA 54:10.19.2]

926.3 Clearance. The installation of pool heaters shall comply with the following requirements:

(1) The clearances shall not interfere with combustion air, draft hood or vent terminal clearance and relief, and accessibility for servicing.

(2) A pool heater shall be installed in accordance with its listing and the manufacturer’s installation instructions.

[NFPA 54:10.19.3]

Frequently asked questions

Can I reduce clearances if the heater is listed for reduced clearances?

Yes. If a heater is listed for reduced clearances, install it according to its listing and manufacturer’s instructions rather than the generic numeric minimums in the CMC (§ 925.3(1)) .

How do I size ventilation for multiple unvented infrared heaters?

Add the installed input ratings (Btu/h) for all unvented infrared heaters, divide by 1,000, and multiply by 4 ft³/min to get the required supply and exhaust rate (4 ft³/min per 1,000 Btu/h) (§ 925.4) .

Are hangers allowed to be plastic or wood?

No. The code requires hangers and brackets to be of noncombustible material for suspended infrared heaters (§ 925.2) .

What if a heater is unlisted — who decides the clearance?

For unlisted heaters, clearances must be acceptable to the Authority Having Jurisdiction (AHJ); provide documentation and proposed clearances for approval, or comply with the code’s numeric minimums where applicable (§ 925.3(2)) .

Where must exhaust openings be placed for unvented heaters?

Exhaust openings required to remove combustion products must be located above the level of the heaters (§ 925.4.1) .

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