Development Services

Mechanical Code Questions

Condensate from air conditioning equipment and cooling coils shall be collected and discharged to an approved plumbing fixture or disposal area. Condensate shall not drain over a public way. Specific requirements are as follows:

  • Condensate must be piped to the sanitary system with an indirect connection into a properly trapped and vented plumbing receptor or directly into its tailpiece; or
  • Condensate may be piped to an approved drywell. When condensate is terminated at a drywell, it shall be an indirect connection to a properly constructed drywell. Handouts specifying drywell construction requirements are available at the Development Services Center. Drywells for draining large tonnage systems and for commercial and industrial projects must be engineered and included as part of the approved plans for the project.

Additional requirements for condensate piping to consider are as follows:

  • Condensate drain lines shall slope not less then 1/8 inch per ft. or 1 percent slope toward the termination and shall be of an approved corrosion resistant material.
  • Condensate drain lines shall be sized in accordance with the California Mechanical Code Section 310.3 or as recommended by the equipment manufacturer.
  • When a cooling coil is located in an attic or furred space where damage may result from condensate overflow, an additional water tight pan of corrosion resistant metal shall be installed beneath the cooling coil to catch overflow condensate due to a clogged primary condensate drain, or one pan with a standing overflow and separate secondary drain may be provided in lieu of the secondary pan. The secondary drain shall be piped to a discharge location where it can be readily observed outdoors such as over a door or window.
Dryer moisture exhaust ducts shall be of metal and shall have smooth interior surfaces. Screws or other fasteners shall not be used that will penetrate the duct wall and obstruct the airflow. Dryer moisture exhaust ducts shall only serve clothes dryers. Unless otherwise permitted or required by the dryer manufacturer’s installation instructions and approved by the Authority Having Jurisdiction, domestic clothes dryer moisture exhaust ducts shall not exceed a total combined horizontal and vertical length of 14 feet, including two 90 degree elbows. Two feet shall be deducted for each 90-degree elbow in excess of two.
Interior spaces intended for human occupancy shall be provided with active or passive space heating systems capable of maintaining a minimum indoor temperature of 68 degrees F. at a point 3 feet above the floor on the design heating day.
Not less then 30 inches in depth, width and height of working space and platform shall be provided to service all equipment on the service/access side of the equipment. Clearances to combustibles shall be in accordance with the equipment manufacturer’s listing and installation instructions. Additional clearances may be required by the equipment manufacturer for service, airflow etc. Clearance for gas vents shall be in accordance with the listed vent manufacturer’s installation instructions.
Environmental exhaust ducts shall terminate a minimum of 3 feet from the property line and 3 feet from openings to the building.