Air Conditioning Unit

A permit is required to install a new air conditioning (AC) unit or replace an existing AC unit. A permit must be obtained prior to the installation of the AC unit.

• You will need the AC unit model equipment information (or the manufactures specification sheet) to complete your permit application.
• Note, if the property is in the flood zone, compliance with California Residential Code (CRC) Section R322.1.6 is required.

For questions, please contact the Building Division at 650-903-6313 or building@mountainview.gov.

Permit Required

A mechanical permit is required.

Cost

Permit fee (includes inspection): $200 to $300

Timeline

Typical Time to Receive Permit: 5 days

1. Verify your project complies with the Zoning and Requirements listed below.
2. Submit for an instant building permit online. No building plans are required.
3. Contractor installs AC unit and schedules City inspection online.
4. On-site inspection completed by City Building Inspector. A successful inspection will result in the permit being finaled.

Zoning Compliance

All AC units located at single-family homes or duplex properties:

• Must be at least 3' from the side or rear property line.
• Cannot be located within the front yard or be visible from the public street. NOTE: For properties within a Homeowners Association, then AC unit must be in HOA-approved location.
• Can be located in the street side yard on a corner lot, but must be located within a fenced yard area.
• If roof-mounted, must be within the height limits of the zoning district where the property is located and screened on all sides, so as to not be visible from the public street. Check your zoning

If you are proposing exterior modifications to a building to accommodate the AC unit, such as a new exterior closet, review by the Planning Division is required prior to issuing a permit for installation. 

Noise Limitations

• All air conditioning units must meet the noise level standards per City Code Section 21.26. Noise must not exceed 50 dBA during the nighttime hours of 10:00 pm to 7:00 am and 55 dBA during the daytime hours of 7:00 am to 10:00 pm.

Requirements

Electrical Requirements

• An electrical disconnect for the unit must be located within sight and readily accessible from the air conditioning or refrigerant equipment. (CEC 440.14)
• Every circuit for the AC equipment shall be legibly identified in the main electrical panel. (CEC 408.4(A))
• Provide a 15 amp- or 20 amp-rated electrical receptacle outlet at an accessible location within 25 feet of the equipment. (CEC 210.63)
• The electrical receptacle for the AC unit shall be GFCI protected, water-resistant and in a weatherproof cover. (CEC 210.8 and 406.9)
• If the existing main electrical panel size (amps) is not sufficient to support the new electrical load for the AC equipment, the main panel must be upgraded to a minimum 200 amp service for a single-family home and a minimum 125 amps service for a duplex. (City Code Section 8.51(C) & (D)) 

Equipment and Specification Requirements

• The condensate disposal must be collected and discharged to an approved plumbing fixture or disposal area (e.g. in landscaping). Condensate, or wastewater, cannot drain over a public sidewalk or public street. (CPC 814.1)
• The compressor or condenser unit must be anchored to a minimum 3-inch-thick concrete slab or approved platform above ground level. An unobstructed, readily accessible opening and passageway to the compressor no less than 36" wide and 80" high must be provided and maintained. (CMC 1105.2 and 1105.3)
• The refrigerant port protection circuit access that is located outdoors must be protected from unauthorized access with a locking-type tamper resistant cap. (CMC 1105.11)
• Installed air conditioner and heat pump outdoor condensing units must have a clearance of at least 5 feet from the outlet (termination) of any dryer vent. (CEnerC, Subchapter 7, 150.0(h)3(A))
• Minimum cooling efficiency for central air conditions and heat pumps up to 45,000 Btu/hour must have a minimum Seasonal Energy Efficiency Rating (SEER) of 14 and an Energy Efficient Ratio (EER) of 12.2 per table 4-6 of the 2022 Residential Compliance Manual.
• Any insulation shall be protected from damage and be suitable for outdoor service, typically protected by aluminum, sheet metal, paint or plastic cover. (CEnerC, Subchapter 7, 150.0(m)9)

Installation Requirements

• The installation of the air conditioning unit must follow the manufacturer’s installation instructions and shall be available on the job site at time of inspection (CRC R106.1.2).
• In all climate zones, when a space-conditioning system is altered by the installation or replacement of space-conditioning system equipment (e.g. replacement of the air handler, outdoor condensing unit of a split system AC unit, or heat pump, cooling or heating coil) a Duct Air Leakage Test performed by a HERS rater is required for altered ducts (CEnerC, Subchapter 9, 150.2(b)(1)(E)).
  
  • Exceptions:
    
    1. Duct systems that are documented to have been previously sealed as confirmed through field verification and diagnostic testing in accordance with procedures in the Residential Appendix Table RA3.1.
    2. Duct systems with less than 40 linear feet as determined by visual inspection.
    3. Existing duct system was constructed, insulated or sealed with asbestos.

    If a Duct Air Leakage Test is performed, the HERS report completed by a HERS rater must be provided to the City Building inspector at the final inspection.