It is the same lanquage as the 2009 UMC. Gravity drains that discharge to the exterior do fail in cold climates (they freeze) They fail in warm climates due to algee and insect nests so we have allowed the float switches for years. As I said ealier I see how one could reach the conclusion that a float switch in not allowed because it is not specifically mentioned but they can be approved under alternate means and methods.
309.0 Condensate Wastes and Control.309.1 Condensate Disposal.
Condensate from air washers,air-cooling coils, fuel-burning condensing appliances, and theoverflow from evaporative coolers and similar water-suppliedequipment or similar air-conditioning equipment shall becollected and discharged to an approved plumbing fixture ordisposal area. If discharged into the drainage system, equipmentshall drain by means of an indirect waste pipe. Thewaste pipe shall have a slope of not less than VB inch per foot(10.5 mm/m) or 1 percent slope and shall be of approvedcorrosion-resistant material not smaller than the outlet size asrequired in either Section 309.3 or 309.4 for air-cooling coilsor condensing fuel-burning appliances, respectively. Condensateor wastewater shall not drain over a public way.
309~2
Condensate Control. When a cooling coil or coolingunit is located in an attic or furred space where damage mayresult from condensate overflow, an additional watertight panof corrosion-resistant metal shall be installed beneath thecooling coil or unit top to catch the overflow condensate dueto a clogged primary condensate drain, or one pan with astanding overflow and a separate secondary drain may beprovided in lieu of the secondary drain pan. The additionalpan or the standing overflow shall be provided with a drainpipe, minimum % inch (19.1 mm) nominal pipe size,discharging at a point that can be readily observed.This requirement is in addition to the requirements inSections 309.3 and 309.4.
309.3 Condensate Waste Sizing.
Condensate waste pipesfrom air-cooling coils shall be sized in accordance with equipmentcapacity as follows:
TABLE 3-1MINIMUM CONDENSATE PIPE SIZE
EQUIPMENT CAPACITY MINIMUM CONDENSATEIN PIPE DIAMETERTons of
(kW)
Inches (mm)Refrigeration
Up to 20 (Up to 70.34)
% (20)21-40 (73.85 - 140.67) 1 (25)41- 90 (144.19 - 316.6) I1f4 (32)91 - 125 (320.03 - 439.6) lYz (40)126 - 250 (443.12 - 879.2) 2 (50)
The size of condensate waste pipes may be for one unitor a combination of units, or as recommended by the manufacturer.The capacity of waste pipes assumes a one-eights
44
(\Is)
inch per foot (10.5 mmlm) or 1 percent slope, with the piperunning three-quarters (%) full at the following conditions:Outside Air - 20% Room Air - 80%DB75°F(24°C)Condensate drain sizing for other slopes or other conditionsshall be approved by the Authority Having Jurisdiction.
309.4 Fuel-Burning Appliance Condensate Drains.
Condensatedrain lines from individual fuel-burning condensing appliancesshall be sized according to the manufacturer'srecommendations. Condensate drain lines serving more thanone appliance shall be approved by the Authority Having Jurisdictionprior to installation.
309.5 Plastic Fittings.
Female PVC screwed fittings shall beused with plastic male fittings and plastic male threads only.
310.0 Personnel Protection.
A suitable and substantial metal guard shall be providedaround exposed flywheels, fans, pulleys, belts, and movingmachinery that are portions of a heating, ventilating, or refrigeratingsystem.
311.0 Heating or Cooling Air System.311.1 Source.
A heating or cooling air system shall beprovided with return air, outside air, or both. A heating orcooling air system regulated by this code and designed toreplace required ventilation shall be arranged to dischargeinto a conditioned space not less than the amount of outsideair specified in Chapter 4.
311.2 Air Filters.
Air filters shall be installed in a heating,cooling, or makeup air system. Such filters shall comply withthe standard, Air Filter Units, Test Performance of, that isreferenced in Chapter 17, as Class I or II filters.
Exception:
Systems serving single guest rooms or dwellingunits shall not require a listed filter.
311.3 Prohibited Source.
Outside or return air for a heatingor cooling air system shall not be taken from the followinglocations
1) Closer than ten (10) feet (3,048 mm) from an appliancevent outlet, a vent opening of a plumbing drainage system,or the discharge outlet of an exhaust fan, unless the outletis three (3) feet (914 mm) above the outside-air inlet.(2) Where it is less than ten (10) feet above the surface ofany abutting public way, driveway, sidewalk, street, alleyor driveway.(3) A hazardous or insanitary location or a refrigerationmachinery room as defined in this code.(4) From an area, the volume of which is less than 25 percentof the entire volume served by such system, unless thereis a permanent opening to an area the volume of which isequal to 25 percent of the entire volume served.
2010 CALIFORNIA MECHANICAL COD