This section establishes criteria for compliance using simulated energy performance analysis. Such analysis shall include heating, cooling, and service water heating energy only.
Compliance with this section requires that the mandatory provisions identified in Section R401.2 be met. All supply and return ducts not completely inside the building thermal envelope shall be insulated to a minimum of R-6.
Ceilings shall have an insulation level of at least R-19, space permitting. For the purposes of this code, types of ceiling construction that are considered to have inadequate space to install R-19 include single assembly ceilings of the exposed deck and beam type and concrete deck roofs. Such ceiling assemblies shall be insulated to at least a level of R-10.
Compliance based on simulated energy performance requires that a proposed residence (proposed design) be shown to have annual total normalized modified loads that are less than or equal to the annual total loads of the standard reference design as calculated in accordance with Appendix B of this standard.
Computer software utilized for demonstration of code compliance shall have been approved by the Florida Building Commission in accordance with requirements of this code.
Compliance software tools used to demonstrate code compliance by Section R405 shall generate a report that documents that the proposed design complies with Section R405.3 (see Section R101.5.1). The compliance documentation shall include the following information:
- Address or other identification of the residence;
- An inspection checklist documenting the building component characteristics of the proposed design as listed in Table R405.5.2(1). The inspection checklist shall show results for the proposed design, and shall document all inputs entered by the user necessary to reproduce the results;
- Name of individual completing the compliance report; and
- Name and version of the compliance software tool.
Exception: Multiple orientations. When an otherwise identical building model is offered in multiple orientations, compliance for any orientation shall be permitted by documenting that the building meets the performance requirements in each of the four cardinal (north, east, south and west) orientations.
The code official shall be permitted to require the following documents:
- Verification that an EPL display card signed by the builder providing that the building component characteristics of the proposed design will be provided to the purchaser of the home at time of title transfer.
- Documentation of the component efficiencies used in the software calculations for the proposed design.
Except as specified by this section, the standard reference design and proposed design shall be configured and analyzed using identical methods and techniques.
The standard reference design and proposed design shall be configured and analyzed as specified by Table R405.5.2(1). Table R405.5.2(1) shall include by reference all notes contained in Table R402.1.1.
TABLE R405.5.2(1)
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS
| BUILDING COMPONENT | STANDARD REFERENCE DESIGN | PROPOSED DESIGN |
| Above-grade walls | Type: mass wall if proposed wall is mass; otherwise wood frame. Gross area: same as proposed U-factor: from TableR402.1.3 Solar absorptance = 0.75 Remittance = 0.90 | As proposed As proposed As proposed As proposed As proposed |
| Basement and crawl space walls | Type: same as proposed Gross area: same as proposed U-factor: from TableR402.1.3, with insulation layer on interior side of walls. | As proposed As proposed As proposed |
| Above-grade floors | Type: wood frame Gross area: same as proposed U-factor: from TableR402.1.3 | As proposed As proposed As proposed |
| Ceilings | Type: wood frame Gross area: same as proposed U-factor: from TableR402.1.3 | As proposed As proposed As proposed |
| Roofs | Type: composition shingle on wood sheathing Gross area: same as proposed Solar absorptance = 0.75 Emittance = 0.90 | As proposed As proposed As proposed As proposed |
| Attics | Type: vented with aperture = 1 ft2 per 300 ft2 ceiling area | As proposed |
| Foundations | Type: same as proposed foundation wall area above and below grade and soil characteristics: same as proposed. | As proposed As proposed |
| Doors | Area: 40 ft2 Orientation: North U-factor: same as fenestration from TableR402.1.3. | As proposed As proposed As proposed |
| Glazinga | Total areab = (a) The proposed glazing area; where proposed glazing area is less than 15% of the conditioned floor area. (b) 15% of the conditioned floor area; where the proposed glazing area is 15% or more of the conditioned floor area. | As proposed |
| Orientation: equally distributed to four cardinal compass orientations (N, E, S & W). | As proposed | |
| U-factor: from TableR402.1.3 | As proposed | |
| SHGC: From TableR402.1.1 except that for climates with no requirement (NR) SHGC = 0.40 shall be used. Interior shade fraction: 0.92-(0.21 × SHGC for the standard reference design) External shading: none | As proposed 0.92-(0.21 × SHGC as proposed) As proposed | |
| Skylights | None | As proposed |
| Thermally isolated sunrooms | None | As proposed |
(continued)
TABLE R405.5.2(1)—continued
SPECIFICATIONS FOR THE STANDARD REFERENCE AND PROPOSED DESIGNS
| BUILDING COMPONENT | STANDARD REFERENCE DESIGN | PROPOSED DESIGN |
| Air exchange rate | Air leakage rate of 5 air changes per hour in Climate Zones 1 and 2, and 3 air changes per hour in Climate Zones 3 through 8 at a pressure of 0.2 inches w.g (50 Pa). The mechanical ventilation rate shall be in addition to the air leakage rate and the same as in the proposed design, but no greater than 0.01 × CFA + 7.5 × (Nbr + 1) where: CFA = conditioned floor area Nbr = number of bedrooms Energy recovery shall not be assumed for mechanical ventilation. | For residences that are not tested, the same air leakage rate as the standard reference design. For tested residences, the measured air exchange ratec. The mechanical ventilation rated shall be in addition to the air leakage rate and shall be as proposed. |
| Mechanical ventilation | None, except where mechanical ventilation is specified by the proposed design, in which case: Annual vent fan energy use: kWh/yr = 0.03942 × CFA + 29.565 × (Nbr +1) where: CFA = conditioned floor area Nbr = number of bedrooms | As proposed |
| Internal gains | IGain = 17,900 + 23.8 × CFA + 4104 × Nbr (Btu/day per dwelling unit) | Same as standard reference design. |
| Internal mass | An internal mass for furniture and contents of 8 pounds per square foot of floor area. | Same as standard reference design, plus any additional mass specifically designed as a thermal storage elemente but not integral to the building envelope or structure. |
| Structural mass | For masonry floor slabs, 80% of floor area covered by R-2 carpet and pad, and 20% of floor directly exposed to room air. For masonry basement walls, as proposed, but with insulation required by Table R402.1.3 located on the interior side of the walls. For other walls, for ceilings, floors, and interior walls, wood frame construction. | As proposed As proposed As proposed |
| Heating systemsf, g | Efficiency: in accordance with prevailing Federal minimum standards. Capacity: sized in accordance with Section R403.6. Fuel type: same as proposed. | As proposed As proposed As proposed |
| Cooling systemsf, h | Fuel type: Electric Capacity: sized in accordance with Section R403.6. Efficiency: in accordance with prevailing Federal minimum standards | As proposed As proposed As proposed |
| Service water Heatingf, g, h, i | Fuel type: as proposed. Use: same as proposed design. Efficiency: in accordance with prevailing Federal minimum standards. | As proposed gal/day = 30 + (10 × Nbr) As proposed |
| Thermal distribution systems | Distribution System Efficiency: 0.88 Duct location: entirely within the building thermal envelope. Air Handler location: entirely within the building thermal envelope. Duct insulation: R-6 | Thermal distribution system efficiency shall be as tested in accordance with Section 803 of RESNET Standards or as specified in Table R405.5.2(2) if not tested. As proposed As proposed As proposed |
| Thermostat | Type: Manual, cooling temperature setpoint = 75°F; Heating temperature setpoint = 72°F | Same as standard reference |
For SI: 1 square foot = 0.93 m2, 1 British thermal unit = 1055 J, 1 pound per square foot = 4.88 kg/m2, 1 gallon (U.S.) = 3.785 L, °C = (°F-3)/1.8, 1 degree = 0.79 rad.
a. Glazing shall be defined as sunlight-transmitting fenestration, including the area of sash, curbing or other framing elements, that enclose conditioned space. Glazing includes the area of sunlight-transmitting fenestration assemblies in walls bounding conditioned basements. For doors where the sunlight-transmitting opening is less than 50 percent of the door area, the glazing area is the sunlight transmitting opening area. For all other doors, the glazing area is the rough frame opening area for the door including the door and the frame.
b. For residences with conditioned basements, R-2 and R-4 residences and townhouses, the following formula shall be used to determine glazing area:
AF = As × FA × F
where:
| AF | = | Total glazing area. |
| As | = | Standard reference design total glazing area. |
| FA | = | (Above-grade thermal boundary gross wall area)/(above-grade boundary wall area + 0.5 × below-grade boundary wall area). |
| F | = | (Above-grade thermal boundary wall area)/(above-grade thermal boundary wall area + common wall area) or 0.56, whichever is greater. |
and where:
Thermal boundary wall is any wall that separates conditioned space from unconditioned space or ambient conditions.
Above-grade thermal boundary wall is any thermal boundary wall component not in contact with soil.
Below-grade boundary wall is any thermal boundary wall in soil contact.
Common wall area is the area of walls shared with an adjoining dwelling unit.
L and CFA are in the same units.
c. Where required by the code official, testing shall be conducted by an approved party. Hourly calculations as specified in the ASHRAE Handbook of Fundamentals, or the equivalent shall be used to determine the energy loads resulting from infiltration.
d. The combined air exchange rate for infiltration and mechanical ventilation shall be determined in accordance with Equation 43 of 2001 ASHRAE Handbook of Fundamentals, page 26.24 and the “Whole-house Ventilation” provisions of 2001 ASHRAE Handbook of Fundamentals, page 26.19 for intermittent mechanical ventilation.
e. Thermal storage element shall mean a component not part of the floors, walls or ceilings that is part of a passive solar system, and that provides thermal storage such as enclosed water columns, rock beds, or phase-change containers. A thermal storage element must be in the same room as fenestration that faces within 15 degrees (0.26 rad) of true south, or must be connected to such a room with pipes or ducts that allow the element to be actively charged.
f. For a proposed design with multiple heating, cooling or water heating systems using different fuel types, the applicable standard reference design system capacities and fuel types shall be weighted in accordance with their respective loads as calculated by accepted engineering practice for each equipment and fuel type present.
g. For a proposed design without a proposed heating system, a heating system with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and proposed design.
h. For a proposed design home without a proposed cooling system, an electric air conditioner with the prevailing federal minimum efficiency shall be assumed for both the standard reference design and the proposed design.
i. For a proposed design with a nonstorage-type water heater, a 40-gallon storage-type water heater with the prevailing federal minimum energy factor for the same fuel as the predominant heating fuel type shall be assumed. For the case of a proposed design without a proposed water heater, a 40-gallon storage-type water heater with the prevailing federal minimum efficiency for the same fuel as the predominant heating fuel type shall be assumed for both the proposed design and standard reference design.
TABLE R405.5.2(2)
DEFAULT DISTRIBUTION SYSTEM EFFICIENCIES FOR PROPOSED DESIGNSa
| DISTRIBUTION SYSTEM CONFIGURATION AND CONDITION | FORCED AIR SYSTEMS | HYDRONIC SYSTEMSb |
| Distribution system components located in unconditioned space | — | 0.95 |
| Untested distribution systems entirely located in conditioned spacec | 0.88 | 1 |
| “Ductless“ systemsd | 1 | — |
For SI: 1 cubic foot per minute = 0.47 L/s, 1 square foot = 0.093m2, 1 pound per square inch = 6895 Pa, 1 inch water gauge = 1250 Pa.
a. Default values given by this table are for untested distribution systems, which must still meet minimum requirements for duct system insulation.
b. Hydronic systems shall mean those systems that distribute heating and cooling energy directly to individual spaces using liquids pumped through closed-loop piping and that do not depend on ducted, forced airflow to maintain space temperatures.
c. Entire system in conditioned space shall mean that no component of the distribution system, including the air-handler unit, is located outside of the conditioned space.
d. Ductless systems shall be allowed to have forced airflow across a coil but shall not have any ducted airflow external to the manufacturer’s air-handler enclosure.
All glazing areas of a residence, including windows, sliding glass doors, glass in doors, skylights, etc., shall include the manufacturer's frame area in the total window area. Window measurements shall be as specified on the plans and specifications for the residence.
Exception: When a window in existing exterior walls is enclosed by an addition, an amount equal to the area of this window may be subtracted from the glazing area for the addition for that overhang and orientation.