MANDATORY REQUIREMENTS -
(Continued)
Building framing cavities shall not be used as ducts or plenums.
Mechanical system piping capable of carrying fluids above 105°F (41°C)
or below 55°F (13°C) shall be insulated to a minimum of R-3.
R403.4.1 Protection of piping insulation.
If heated water circulation systems are
installed, they shall be in accordance with Section R403.5.1.1. Heat trace temperature maintenance systems shall be in accordance with
Section R403.5.1.2. Automatic controls, temperature sensors and pumps shall be accessible. Manual controls shall be readily accessible.
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R403.3.5 Building cavities (Mandatory).
R403.4 Mechanical system piping insulation (Mandatory).
R403.5.1 Heated water circulation and temperature maintenance systems (Mandatory).
SECTION R403 SYSTEMS
R402.4.5 Recessed lighting.
Recessed luminaires installed in the building thermal envelope shall be sealed to limit air leakage
between conditioned and unconditioned spaces. All recessed luminaires shall be IC-rated and labeled as having an air leakage rate not
more than 2.0 cfm (0.944 L/s) when tested in accordance with ASTM E283 at a 1.57 psf (75 Pa) pressure differential. All recessed
luminaires shall be sealed with a gasket or caulk between the housing and the interior wall or ceiling covering.
R402.4.4 Rooms containing fuel-burning appliances.
In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to
open combustion fuel burning appliances, the appliances and combustion air opening shall be located outside the building thermal envelope or
enclosed in a room, isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements
of Table R402.1.2, where the walls, floors and ceilings shall meet not less than the basement wall R-value requirement. The door into the room shall be
fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it
passes through conditioned space to a minimum of R-8.
Exceptions:
Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
Fireplaces and stoves complying with Section R402.4.2 and Section R1006 of the Florida Building Code, Residential.
R403.1.3 Heat pump supplementary heat (Mandatory).
Heat pumps having supplementary electric-resistance heat shall have controls
that, except during defrost, prevent supplemental heat operation when the heat pump compressor can meet the heating load.
R403.3.2 Sealing (Mandatory)
All ducts, air handlers, filter boxes and building cavities that form the primary air containment passageways
for air distribution systems shall be considered ducts or plenum chambers, shall be constructed and sealed in accordance with Section
C403.2.9.2 of the Commercial Provisions of this code and shall be shown to meet duct tightness criteria below.
Duct tightness shall be verified by testing in accordance with ANSI/RESNET/ICC 380 by either individuals as defined in Section 553.993(5) or
(7), Florida Statutes, or individuals licensed as set forth in Section 489.105(3)(f), (g) or (i), Florida Statutes, to be “substantially leak free” in
accordance with Section R403.3.3.
Postconstruction test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the entire
system, including the manufacturer’s air handler enclosure. Registers shall be taped or otherwise sealed during the test.
Rough-in test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the system,
including the manufacturer’s air handler enclosure if installed at the time of the test. All registers shall be taped or otherwise
sealed during the test.
2.
1.
Exceptions:
A duct air leakage test shall not be required where the ducts and air handlers are located entirely within the building
thermal envelope.
Duct testing is not mandatory for buildings complying by Section 405 of this code. Duct leakage testing is required for Section
R405 compliance where credit is taken for leakage, and a duct air leakage Qn to the outside of less than 0.080 (where Qn =
duct leakage to the outside in cfm per 100 square feet of conditioned floor area tested at 25 Pascals) is indicated in the
compliance report for the proposed design.
2.
1.
R403.1 Controls.
R403.1.1 Thermostat provision (Mandatory).
At least one thermostat shall be provided for each separate heating and cooling system.
R403.3.2.1 Sealed air handler.
Air handlers shall have a manufacturer’s designation for an air leakage of no more than 2 percent
of the design airflow rate when tested in accordance with ASHRAE 193.
R403.3.3 Duct testing (Mandatory).
Ducts shall be pressure tested to determine air leakage by one of the following methods:
A written report of the results of the test shall be signed by the party conducting the test and provided to the code official.
Piping insulation exposed to weather shall be protected from damage, including that
caused by sunlight, moisture, equipment maintenance and wind, and shall provide shielding from solar radiation that can cause
degradation of the material. Adhesive tape shall not be permitted.
1.
2.
R403.5.1.1 Circulation systems.
R403.5.1.2 Heat trace systems.
Heated water circulation systems shall be provided with a circulation pump. The system return pipe shall
be a dedicated return pipe or a cold water supply pipe. Gravity and thermosiphon circulation systems shall be prohibited. Controls for
circulating hot water system pumps shall start the pump based on the identification of a demand for hot water within the occupancy. The
controls shall automatically turn off the pump when the water in the circulation loop is at the desired temperature and when there is no
demand for hot water.
Electric heat trace systems shall comply with IEEE 515.1 or UL 515. Controls for such systems shall
automatically adjust the energy input to the heat tracing to maintain the desired water temperature in the piping in accordance with the
times when heated water is used in the occupancy.