Michigan Administrative Code › Department - Licensing and Regulatory Affairs › Bureau of Construction Codes › Construction Code Commission General Rules › Construction Code › Part 10 - MICHIGAN UNIFORM ENERGY CODE › Section R. 408.31070 - Steel-frame ceilings, walls, and floors

Current through Vol. 24-12, July 15, 2024
Rule 1070. Section R402.2.6 of the code are amended to
						read as follows:
R402.2.6. Steel-frame ceilings, walls, and floors.
						Steel-frame ceilings, walls, and floors shall meet the insulation requirements
						of table R402.2.6 or shall meet the U-factor requirements in table R402.1.3.
						The calculation of the U-factor for a steel-frame envelope assembly shall use a
						series-parallel path calculation method.
R408.31071 Simulated performance alternative.
Rule 1071. Table R405.5.2(1) of the code is amended to
						read as follows:
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
As proposed
wall is mass; otherwise wood frame.
As proposed
Gross area: same as proposed
As proposed
U-factor: from Table 402.1.3
As proposed
Solar absorptance = 0.75
As proposed
Remittance = 0.90
Basement and crawl space
Type: same as proposed
As proposed
walls
Gross area: same as proposed U-factor: from
									 Table R402.1.3, with insulation layer on interior side of walls.
As proposed As proposed
Above-grade floors
Type: wood frame
Gross area: same as proposed
U-factor: from Table R402.1.3
As proposed As proposed As proposed
Ceilings
Type: wood frame
Gross area: same as proposed
U-factor: from Table R402.1.3
As proposed As proposed As proposed
Roofs
Type: composition shingle on wood
									 sheathing
As proposed
Gross area: same as proposed Solar absorptance
									 = 0.75 Emittance = 0.90
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 Table
									 R402.1.3.
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.
As proposed
(b) 15% of the conditioned floor area: where
									 the proposed glazing area is 15% or more of the conditioned floor area.
Orientation: equally distributed to 4 cardinal
									 compass orientations (N, E, S & W).
As proposed
U-factor: from Table R402.1.3
As proposed
SHGC: From Table R402.1.1 except that for
									 climates with no requirement (NR) SHGC = 0.40 shall be used. Interior shade
									 fraction: 0.92-
As proposed 0.92-(0.21 x SHGC as
									 proposed)
(0.21 x SHGC for the standard reference design)
									 External shading: none
As proposed
Skylights
None
As proposed
Thermally isolated sunrooms
None
As proposed
Air exchange rate
Air leakage rate of 4 air changes per hour 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 x CFA + 7.5 x (Nbr = 1)
where:
CFA = conditioned floor area
Nbr = number of bedrooms Energy recovery shall
									 not be assumed for mechanical ventilation.
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: kWh/yr = 0.03942 x CFA +
									 29.565 x (Nbr + 1) where:
CFA = conditioned floor area Nbr + number of
									 bedrooms
As proposed
Internal gains
IGain = 17,900 + 23.8 x CFA + 4104 x 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
As proposed As proposed
the walls.
For other walls, ceilings, floors, and interior
									 walls, wood frame construction.
As proposed
Heating
									 systemsf,g
As proposed for other than electric heating
									 without a heat pump. Where the proposed design utilizes electric heating
									 without a heat pump, the standard reference design shall be an air source heat
									 pump meeting the requirements of the Michigan energy code-commercial
									 provisions. Capacity: sized in accordance with section R403.6.
As proposed
Cooling
									 systemsf,h
As proposed
Capacity: sized in accordance with section
									 R403.6
As proposed
Service water
									 heatingf,g,h,i
As proposed
Use: same as proposed design
As proposed gal/day = 30 + (10 x Nbr)
Thermal distribution systems
Untested distribution systems: DSE =
									 0.88
Tested ducts: Leakage rate to outside
									 conditioned space as specified section R403.2.2
Tested duct location: Unconditioned
									 attic
Tested duct insulation: in accordance with
									 section R403.2.1
Untested distribution systems: DSE from Table
									 R405.5.2(2)
Tested ducts: Tested leakage rate to outside
									 conditioned space
Duct location: As proposed
Duct insulation: 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, 1 inch water gauge = 1250
						Pa.
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 %
						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 x FA x 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 x 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 a certified independent third 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 non-storage-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.