Heating and cooling equipment and appliances shall be located with respect to building construction and other equipment and appliances to permit maintenance, servicing and replacement. Clearances shall be maintained to permit cleaning of heating and cooling surfaces; replacement of filters, blowers, motors, controls and vent connections; lubrication of moving parts; and adjustments.
Exception: Access shall not be required for ducts, piping, or other components approved for concealment.
Heating and cooling equipment and appliances shall be sized in accordance with ACCA Manual S or other approved sizing methodologies based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies.
Exception: Heating and cooling equipment and appliance sizing shall not be limited to the capacities determined in accordance with Manual S or other approved sizing methodologies where any of the following conditions apply:
- The specified equipment or appliance utilizes multi-stage technology or variable refrigerant flow technology and the loads calculated in accordance with the approved heating and cooling methodology fall within the range of the manufacturer’s published capacities for that equipment or appliance.
- The specified equipment or appliance manufacturer’s published capacities cannot satisfy both the total and sensible heat gains calculated in accordance with the approved heating and cooling methodology and the next larger standard size unit is specified.
- The specified equipment or appliance is the lowest capacity unit available from the specified manufacturer.
Radiant panels installed on wood framing shall conform to the following requirements:
- Heating panels shall be installed parallel to framing members and secured to the surface of framing members or mounted between framing members.
- Mechanical fasteners shall penetrate only the unheated portions provided for this purpose. Panels shall not be fastened at any point closer than 1/4 inch (6.4 mm) to an element. Other methods of attachment of the panels shall be in accordance with the panel manufacturer’s instructions.
- Unless listed and labeled for field cutting, heating panels shall be installed as complete units.
Radiant heating systems installed in concrete or masonry shall conform to the following requirements:
- Radiant heating systems shall be identified as being suitable for the installation, and shall be secured in place as specified in the manufacturer’s installation instructions.
- Radiant heating panels or radiant heating panel sets shall not be installed where they bridge expansion joints unless protected from expansion and contraction.
Location of floor furnaces shall conform to the following requirements:
- Floor registers of floor furnaces shall be installed not less than 6 inches (152 mm) from a wall.
- Wall registers of floor furnaces shall be installed not less than 6 inches (152 mm) from the adjoining wall at inside corners.
- The furnace register shall be located not less than 12 inches (305 mm) from doors in any position, draperies or similar combustible objects.
- The furnace register shall be located at least 5 feet (1524 mm) below any projecting combustible materials.
- The floor furnace burner assembly shall not project into an occupied under-floor area.
- The floor furnace shall not be installed in concrete floor construction built on grade.
- The floor furnace shall not be installed where a door can swing within 12 inches (305 mm) of the grille opening.
Floor furnace installations shall conform to the following requirements:
- Thermostats controlling floor furnaces shall be located in the room in which the register of the floor furnace is located.
- Floor furnaces shall be supported independently of the furnace floor register.
- Floor furnaces shall be installed not closer than 6 inches (152 mm) to the ground. Clearance may be reduced to 2 inches (51 mm), provided that the lower 6 inches (152 mm) of the furnace is sealed to prevent water entry.
- Where excavation is required for a floor furnace installation, the excavation shall extend 30 inches (762 mm) beyond the control side of the floor furnace and 12 inches (305 mm) beyond the remaining sides. Excavations shall slope outward from the perimeter of the base of the excavation to the surrounding grade at an angle not exceeding 45 degrees (0.79 rad) from horizontal.
- Floor furnaces shall not be supported from the ground.
The location of vented wall furnaces shall conform to the following requirements:
- Vented wall furnaces shall be located where they will not cause a fire hazard to walls, floors, combustible furnishings or doors. Vented wall furnaces installed between bathrooms and adjoining rooms shall not circulate air from bathrooms to other parts of the building.
- Vented wall furnaces shall not be located where a door can swing within 12 inches (305 mm) of the furnace air inlet or outlet measured at right angles to the opening. Doorstops or door closers shall not be installed to obtain this clearance.
Vented wall furnace installations shall conform to the following requirements:
- Required wall thicknesses shall be in accordance with the manufacturer’s installation instructions.
- Ducts shall not be attached to a wall furnace. Casing extensions or boots shall be installed only when listed as part of a listed and labeled appliance.
- A manual shut off valve shall be installed ahead of all controls.
- Listed room heaters shall be installed on noncombustible floors, assemblies constructed of noncombustible materials or listed floor protectors with materials and dimensions in accordance with the appliance manufacturer’s instructions.
- Room heaters listed for installation on combustible floors without floor protection shall be installed in accordance with the appliance manufacturer’s instructions.
In addition to the requirements of Section M1411.3, a secondary drain or auxiliary drain pan shall be required for each cooling or evaporator coil where damage to any building components will occur as a result of overflow from the equipment drain pan or stoppage in the condensate drain piping. Such piping shall maintain a minimum horizontal slope in the direction of discharge of not less than 1/8 unit vertical in 12 units horizontal (1-percent slope). Drain piping shall be a minimum of 3/4-inch (19 mm) nominal pipe size. One of the following methods shall be used:
- An auxiliary drain pan with a separate drain shall be installed under the coils on which condensation will occur. The auxiliary pan drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain. The pan shall have a minimum depth of 1.5 inches (38 mm), shall not be less than 3 inches (76 mm) larger than the unit or the coil dimensions in width and length and shall be constructed of corrosion-resistant material. Galvanized sheet steel pans shall have a minimum thickness of not less than 0.0236-inch (0.6010 mm) (No. 24 Gage). Nonmetallic pans shall have a minimum thickness of not less than 0.0625 inch (1.6 mm).
- A separate overflow drain line shall be connected to the drain pan installed with the equipment. This overflow drain shall discharge to a conspicuous point of disposal to alert occupants in the event of a stoppage of the primary drain. The overflow drain line shall connect to the drain pan at a higher level than the primary drain connection.
- An auxiliary drain pan without a separate drain line shall be installed under the coils on which condensation will occur. This pan shall be equipped with a water level detection device conforming to UL 508 that will shut off the equipment served prior to overflow of the pan. The pan shall be equipped with a fitting to allow for drainage. The auxiliary drain pan shall be constructed in accordance with Item 1 of this section.
- A water level detection device conforming to UL 508 shall be installed that will shut off the equipment served in the event that the primary drain is blocked. The device shall be installed in the primary drain line, the overflow drain line or the equipment-supplied drain pan, located at a point higher than the primary drain line connection and below the overflow rim of such pan.
Category IV condensing appliances shall have an auxiliary drain pan where damage to any building component will occur as a result of stoppage in the condensate drainage system. These pans shall be installed in accordance with the applicable provisions of Section M1411.3.
- According to the manufacturer’s instructions.
- On level platforms in accordance with Section M1305.1.4.1.
- So that openings in exterior walls are flashed in accordance with Section R703.8.
- So as to protect the potable water supply in accordance with Section P2902.
- So that air intake opening locations are in accordance with Section R303.5.1.