Electrical power and lighting systems, other than those systems or portions thereof required for emergency use only, shall meet these requirements.

401.1 Electrical Distribution Systems.

401.1.1 Check Metering. Single-tenant buildings with a service over 250 kVA and tenant spaces with a connected load over 100 kVA in multiple-tenant buildings shall have provisions for check metering of electrical consumption. The electrical power feeders for which provision for check metering is required shall be subdivided as follows:

401.1.1.1 Lighting and receptacle outlets

401.1.1.2 HVAC systems and equipment

401.1.1.3 Service water heating (SWH), elevators, and special occupant equipment or systems of more than 20 kW.

401.1.1.4 Exception to 401.1.1.1 through 401.1.1.3: 10 percent or less of the loads on a feeder may be from another usage or category.

401.1.2 Tenant-shared HVAC and service hot water systems in multiple tenant buildings shall have provision to be separately check metered.

401.1.3 Subdivided feeders shall contain provisions for portable or permanent check metering. The minimum acceptable arrangement for compliance shall provide a safe method for access by qualified persons to the enclosures through which feeder conductors pass and provide sufficient space to attach clamp-on or split core current transformers. These enclosures may be separate compartments or combined spaces with electrical cabinets serving another function. Dedicated enclosures so furnished shall be identified as to measuring function available.

401.1.4 Electrical Schematic. The person responsible for installing the electrical distribution system shall provide the Federal building manager a single-line diagram of the record drawing for the electrical distribution system, which includes the location of check metering access, schematic diagrams of non-HVAC electrical control systems, and electrical equipment manufacturer's operating and maintenance literature.

401.2 Electric Motors. All permanently wired polyphase motors of 1 hp or more shall meet these requirements:

401.2.1 Efficiency. NEMA design A & B squirrel-cage, foot-mounted, T-frame induction motors having synchronous speeds of 3600, 1800, 1200, and 900 rpm, expected to operate more than 1000 hours per year shall have a nominal full-load efficiency no less than that shown in Table 401.2.1 or shall be classified as an “energy efficient motor” in accordance with RS-3 (incorporated by reference, see § 434.701). The following are not covered:

(a) Multispeed motors used in systems designed to use more than one speed.

(b) Motors used as a component of the equipment meeting the minimum equipment efficiency requirements of subsection 403, provided that the motor input is included when determining the equipment efficiency.

401.3 Lighting Power Allowance. The lighting system shall meet the provisions of subsections 401.3.1 through 401.3.5.

401.3.1 Building Exteriors. The total connected exterior lighting power for the building, or a facility containing multiple buildings, shall not exceed the total exterior lighting power allowance, which is the sum of the individual allowances determined from Table 401.3.1. The individual allowances are determined by multiplying the specific area or length of each area description times the allowance for that area. Exceptions are as follows: Lighting for outdoor manufacturing or processing facilities, commercial greenhouses, outdoor athletic facilities, public monuments, designated high-risk security areas, signs, retail storefronts, exterior enclosed display windows, and lighting specifically required by local ordinances and regulations.

401.3.1.1 Trade-offs of exterior lighting budgets among exterior areas shall be allowed provided the total connected lighting power of the exterior area does not exceed the exterior lighting power allowance. Trade-offs between interior lighting power allowances and exterior lighting power allowances shall not be allowed.

401.3.2 Building interiors. The total connected interior lighting power for a building, including adjustments in accordance with subsection 401.3.3, shall not exceed the total interior lighting power allowance explained in this paragraph. Using Table 401.3.2a, multiply the interior lighting power allowance value by the gross lighted area of the most appropriate building or space activity. For multi-use buildings, using Table 401.3.2a, select the interior power allowance value for each activity using the column for the gross lighted area of the whole building and multiply it by the associated gross area for that activity. The interior lighting power allowance is the sum of all the wattages for each area/activity. Using Table 401.3.2b, c, or d, multiply the interior lighting power allowance values of each individual area/activity by the area of the space and by the area factor from Figure 401.3.2e, based on the most appropriate area/activity provided. The interior lighting power allowance is the sum of the wattages for each individual space. When over 20% of the building's tasks or interior areas are undefined, the most appropriate value for that building from Table 401.3.2a shall be used for the undefined spaces. Exceptions are as follows:

(a) Lighting power that is an essential technical element for the function performed in theatrical, stage, broadcasting, and similar uses.

(b) Specialized medical, dental, and research lighting.

(c) Display lighting for exhibits in galleries, museums, and monuments.

(d) Lighting solely for indoor plant growth (between the hours of 10:00 pm and 6:00 am).

(e) Emergency lighting that is automatically off during normal building operation.

(f) High-risk security areas.

(g) Spaces specifically designed for the primary use by the physically impaired or aged.

(h) Lighting in dwelling units.

401.3.2.1 Trade-offs of the interior lighting power budgets among interior spaces shall be allowed provided the total connected lighting power within the building does not exceed the interior lighting power allowance. Trade-offs between interior lighting power allowances and exterior lighting power allowances shall not be allowed.

401.3.2.2 Building/Space Activities. Definitions of buildings/space activity as they apply to Table 401.3.2a are as follows. These definitions are necessary to characterize the activities for which lighting is provided. They are applicable only to Table 401.3.2a. They are not intended to be used elsewhere in place of building use group definitions provided in the Building Code. They are not included in § 434.201, “Definitions,” to avoid confusion with “Occupancy Type Categories.”

(a) Food service, fast food, and cafeteria: This group includes cafeterias, hamburger and sandwich stores, bakeries, ice cream parlors, cookie stores, and all other kinds of retail food service establishments in which customers are generally served at a counter and their direct selections are paid for and taken to a table or carried out.

(b) Garages: This category includes all types of parking garages, except for service or repair areas.

(c) Leisure dining and bar: This group includes cafes, diners, bars, lounges, and similar establishments where orders are placed with a wait person.

(d) Mall concourse, multi-store service: This group includes the interior of multifunctional public spaces, such as shopping center malls, airports, resort concourses and malls, entertainment facilities, and related types of buildings or spaces.

(e) Offices: This group includes all kinds of offices, including corporate and professional offices, office/laboratories, governmental offices, libraries, and similar facilities, where paperwork occurs.

(f) Retail: A retail store, including departments for the sale of accessories, clothing, dry goods, electronics, and toys, and other types of establishments that display objects for direct selection and purchase by consumers. Direct selection means literally removing an item from display and carrying it to the checkout or pick-up at a customer service facility.

(g) Schools: This category, subdivided by pre-school/elementary, junior high/high school, and technical/vocational, includes public and private educational institutions, for children or adults, and may also include community centers, college and university buildings, and business educational centers.

(h) Service establishment: A retail-like facility, such as watch repair, real estate offices, auto and tire service facilities, parts departments, travel agencies and similar facilities, in which the customer obtains services rather than the direct selection of goods.

(i) Warehouse and storage: This includes all types of support facilities, such as warehouses, barns, storage buildings, shipping/receiving buildings, boiler or mechanical buildings, electric power buildings, and similar buildings where the primary visual task is large items.

401.3.2—Tables and Figures Figure 401.3.2e—Area Factor Formula Area Factor Formula: Area Factor (AF) = 0.2 + 0.8(1/0.9 n) Where: AF = area factor, CH = ceiling height (ft), Ar = space area (ft 2). If AF <1.0 use 1.0; if AF >1.8 use 1.8

401.3.3 Lighting Power Control Credits. The interior connected lighting power determined in accordance with § 434.401.3.2 can be decreased for luminaries that are automatically controlled for occupancy, daylight, lumen maintenance, or programmable timing. The adjusted interior connected lighting power shall be determined by subtracting the sum of all lighting power control credits from the interior connected lighting power. Using Table 401.3.3, the lighting power control credit equals the power adjustment factor times the connected lighting power of the controlled lighting. The lighting power adjustment shall be applied with the following limitations:

(a) It is limited to the specific area controlled by the automatic control device.

(b) Only one lighting power adjustment may be used for each building space or luminaire, and 50 percent or more of the controlled luminaire shall be within the applicable space.

(c) Controls shall be installed in series with the lights and in series with all manual switching devices.

(d) When sufficient daylight is available, daylight sensing controls shall be capable of reducing electrical power consumption for lighting (continuously or in steps) to 50 percent or less of maximum power consumption.

(e) Daylight sensing controls shall control all luminaires to which the adjustment is applied and that direct a minimum of 50 percent of their light output into the daylight zone.

(f) Programmable timing controls shall be able to program different schedules for occupied and unoccupied days, be readily accessible for temporary override with automatic return to the original schedule, and keep time during power outages for at least four hours.

401.3.4 Lighting controls.

401.3.4.1 Type of Lighting Controls. All lighting systems shall have controls, with the exception of emergency use or exit lighting.

401.3.4.2 Number of Manual Controls. Spaces enclosed by walls or ceiling-high partitions shall have a minimum of one manual control (on/off switch) for lighting in that space. Additional manual controls shall be provided for each task location or for each group of task locations within an area of 450 ft 2 or less. For spaces with only one lighting fixture or with a single ballast, one manual control is required. Exceptions are as follows:

401.3.4.2.1 Continuous lighting for security;

401.3.4.2.2 Systems in which occupancy sensors, local programmable timers, or three-level (including OFF) step controls or preset dimming controls are substituted for manual controls at the rate of one for every two required manual controls, providing at least one control is installed for every 1500 watts of power.

401.3.4.2.3 Systems in which four-level (including OFF) step controls or preset dimming controls or automatic or continuous dimming controls are substituted for manual controls at a rate of one for every three required manual controls, providing at least one control is installed for every 1500 watts of power.

401.3.4.2.4 Spaces that must be used as a whole, such as public lobbies, retail stores, warehouses, and storerooms.

401.3.4.3 Multiple Location Controls. Manual controls that operate the same load from multiple locations must be counted as one manual control.

401.3.4.4 Control Accessibility. Lighting controls shall be readily accessible from within the space controlled. Exceptions are as follows: Controls for spaces that are to be used as a whole, automatic controls, programmable controls, controls requiring trained operators, and controls for safety hazards and security.

401.3.4.5 Hotel and Motel Guest Room Control. Hotel and motel guest rooms and suites shall have at least one master switch at the main entry door that controls all permanently wired lighting fixtures and switched receptacles excluding bathrooms. The following exception applies: Where switches are provided at the entry to each room of a multiple-room suite.

401.3.4.6 Switching of Exterior Lighting. Exterior lighting not intended for 24-hour use shall be automatically switched by either timer or photocell or a combination of timer and photocell. When used, timers shall be capable of seven-day and seasonal daylight schedule adjustment and have power backup for at least four hours.

401.3.5 Ballasts.

401.3.5.1 Tandem Wiring. One-lamp or three-lamp fluorescent luminaries that are recess mounted within 10 ft center-to-center of each other, or pendant mounted, or surface mounted within 1 ft of each other, and within the same room, shall be tandem wired, unless three-lamp ballasts are used.

401.3.5.2 Power Factor. All ballasts shall have a power factor of at least 90%, with the exception of dimming ballasts, and ballasts for circline and compact fluorescent lamps and low wattage high intensity discharge (HID) lamps not over 100 W.

The building envelope and its associated assemblies and materials shall meet the provisions of this section.

402.1 Calculations and Supporting Information.

402.1.1 Material Properties. Information on thermal properties, building envelope system performance, and component heat transfer shall be obtained from RS-4. When the information is not available from RS-4, (incorporated by reference, see § 434.701) the data shall be obtained from manufacturer's information or laboratory or field test measurements using RS-5, RS-6, RS-7, or RS-8 (incorporated by reference, see § 434.701).

402.1.1.1 The shading coefficient (SC) for fenestration shall be obtained from RS-4 (incorporated by reference, see § 434.701) or from manufacturer's test data. The shading coefficient of the fenestration, including both internal and external shading devices, is SCX and excludes the effect of external shading projections, which are calculated separately. The shading coefficient used for louvered shade screens shall be determined using a profile angle of 30 degrees as found in Table 41, Chapter 27 of RS-4 (incorporated by reference, see § 434.701).

402.1.2 Thermal Performance Calculations. The overall thermal transmittance of the building envelope shall be calculated in accordance with Equation 402.1.2:

$$ Where: Uo = the area-weighted average thermal transmittance of the gross area of the building envelope; i.e., the exterior wall assembly including fenestration and doors, the roof and ceiling assembly, and the floor assembly, Btu/(h·ft 2·°F) Ao = the gross area of the building envelope, ft 2 Ui = the thermal transmittance of each individual path of the building envelope, i.e., the opaque portion or the fenestration, Btu/(h·ft 2·°F) Ui = 1/Ri (where Ri is the total resistance to heat flow of an individual path through the building envelope) Ai = the area of each individual element of the building envelope, ft 2

The thermal transmittance of each component of the building envelope shall be determined with due consideration of all major series and parallel heat flow paths through the elements of the component and film coefficients and shall account for any compression of insulation. The thermal transmittance of opaque elements of assemblies shall be determined using a series path procedure with corrections for the presence of parallel paths within an element of the envelope assembly (such as wall cavities with parallel paths through insulation and studs). The thermal performance of adjacent ground in below-grade applications shall be excluded from all thermal calculations.

402.1.2.1 Envelope Assemblies Containing Metal Framing. The thermal transmittance of the envelope assembly containing metal framing shall be determined from one of three methods:

(a) Laboratory or field test measurements based on RS-5, RS-6, RS-7, or RS-8 (incorporated by reference, see § 434.701).

(b) The zone method described in Chapter 22 of RS-4 (incorporated by reference, see § 434.701) and the formulas on page 22.10.

(c) For metal roof trusses or metal studs covered by Tables 402.1.2.1a and b, the total resistance of the series path shall be calculated in accordance with the following Equations:

Where: Rt = the total resistance of the envelope assembly Ri = the resistance of the series elements (for i = 1 to n) excluding the parallel path element(s) Re = the equivalent resistance of the element containing the parallel path (R-value of insulation × Fc). Values for Fc and equivalent resistances shall be taken from Tables 402.1.2.1a or b.

402.1.2.2 Envelope Assemblies Containing Nonmetal Framing. The thermal transmittance of the envelope assembly shall be determined from laboratory or field test measurements based on RS-5, RS-6, RS-7, or RS-8 (incorporated by reference, see § 434.701) or from the series-parallel (isothermal planes) method provided in page 23.2 of Chapter 23 of RS-4 (incorporated by reference, see § 434.701).

402.1.2.3 Metal Buildings. For elements with internal metallic structures bonded on one or both sides to a metal skin or covering, the calculation procedure specified in RS-9 (incorporated by reference, see § 434.701) shall be used.

402.1.2.4 Fenestration Assemblies. Determine the overall thermal transmittance of fenestration assemblies in accordance with RS-18 and RS-19 (incorporated by reference, see § 434.701) or by calculation. Calculation of the overall thermal transmittance of fenestration assemblies shall consider the center-of-glass, edge-of-glass, and frame components.

(a) The following equation 402.1.2.4a shall be used.

$$ Where: Uof = the overall thermal transmittance of the fenestration assemblies, including the center-of-glass, edge-of-glass, and frame components, Btu/(h·ft 2·°F) i = numerical subscript (1, 2, . . .n) refers to each of the various fenestration types present in the wall n = the number of fenestration assemblies in the wall assembly Ucg = the thermal transmittance of the center-of-glass area, Btu/(h·ft 2·°F) Acg = the center of glass area, that is the overall visible glass area minus the edge-of-glass area, ft 2 Ueg = the thermal transmittance of the edge of the visible glass area including the effects of spacers in multiple glazed units, Btu/(h·ft 2·°F) Aeg = the edge of the visible glass area, that is the 2.5 in. perimeter band adjacent to the frame, ft 2 Uf = the thermal transmittance of the frame area, Btu/(h·ft 2·°F) Af = the frame area that is the overall area of the entire glazing product minus the center-of-glass area and minus the edge-of-glass area, ft 2

(b) Values of Uof shall be based on one of the following methods:

(1) Results from laboratory test of center-of-glass, edge-of-glass, and frame assemblies tested as a unit at winter conditions. One of the procedures in Section 8.3.2 of RS-1 (incorporated by reference, see § 434.701) shall be used.

(2) Overall generic product C (commercial) in Table 13, Chapter 27, of the RS-4 (incorporated by reference, see § 434.701). The generic product C in Table 13, Chapter 27, is based on a product of 24 ft 2. Larger units will produce lower U-values and thus it is recommended to use the calculation procedure detailed in Equation 402.1.2.4a.

(3) Calculations based on the actual area for center-of-glass, edge-of-glass, and frame assemblies and on the thermal transmittance of components derived from 402.1.2.4a, 402.1.2.4b or a combination of the two.

402.1.3 Gross Areas of Envelope Components.

402.1.3.1 Roof Assembly. The gross area of a roof assembly shall consist of the total surface of the roof assembly exposed to outside air or unconditioned spaces and is measured from the exterior faces of exterior walls and centerline of walls separating buildings. The roof assembly includes all roof or ceiling components through which heat may flow between indoor and outdoor environments, including skylight surfaces but excluding service openings. For thermal transmittance purposes when return air ceiling plenums are employed, the roof or ceiling assembly shall not include the resistance of the ceiling or the plenum space as part of the total resistance of the assembly.

402.1.3.2 Floor Assembly. The gross area of a floor assembly over outside or unconditioned spaces shall consist of the total surface of the floor assembly exposed to outside air or unconditioned space and is measured from the exterior face of exterior walls and centerline of walls separating buildings. The floor assembly shall include all floor components through which heat may flow between indoor and outdoor or unconditioned space environments.

402.1.3.3 Wall Assembly. The gross area of exterior walls enclosing a heated or cooled space is measured on the exterior and consists of the opaque walls, including between-floor spandrels, peripheral edges of flooring, window areas (including sash), and door areas but excluding vents, grilles, and pipes.

402.2 Air Leakage and Moisture Mitigation. The requirements of this section shall apply only to those building components that separate interior building conditioned space from the outdoors or from unconditioned space or crawl spaces. Compliance with the criteria for air leakage through building components shall be determined by tests conducted in accordance with RS-10 (incorporated by reference, see § 434.701).

402.2.1 Air Barrier System. A barrier against leakage shall be installed to prevent the leakage of air through the building envelope according to the following requirements:

(a) The air barrier shall be continuous at all plumbing and heating penetrations of the building opaque wall.

(b) The air barrier shall be sealed at all penetrations of the opaque building wall for electrical and telecommunications equipment.

402.2.2 Building Envelope. The following areas of the building envelope shall be sealed, caulked, gasketed, or weatherstripped to limit air leakage:

(a) Intersections of the fenestration and door frames with the opaque wall sections.

(b) Openings between walls and foundations, between walls and roof and wall panels.

(c) Openings at penetrations of utility service through, roofs, walls, and floors.

(d) Site built fenestration and doors.

(e) All other openings in the building envelope.

Exceptions are as follows: Outside air intakes, exhaust outlets, relief outlets, stair shaft, elevator shaft smoke relief openings, and other similar elements shall comply with subsection 403.

402.2.2.1 Fenestration and Doors Fenestration and doors shall meet the requirements of Table 402.2.1.

402.2.2.2 Building Assemblies Used as Ducts or Plenums. Building assemblies used as ducts or plenums shall be sealed, caulked, and gasketed to limit air leakage.

402.2.2.3 Vestibules. A door that separates conditioned space from the exterior shall be equipped with an enclosed vestibule with all doors opening into and out of the vestibule equipped with self-closing devices. Vestibules shall be designed so that in passing through the vestibule, it is not necessary for the interior and exterior doors to open at the same time. Exceptions are as follows: Exterior doors need not be protected with a vestibule where:

(a) The door is a revolving door.

(b) The door is used primarily to facilitate vehicular movement or material handling.

(c) The door is not intended to be used as a general entrance door.

(d) The door opens directly from a dwelling unit.

(e) The door opens directly from a retail space less than 2,000 ft 2 in area, or from a space less than 1,500 ft 2 for other uses.

(f) In buildings less than three stories in building height in regions that have less than 6,300 heating degree days base 65 °F.

402.2.2.4 Compliance Testing. All buildings shall be tested after completion using the methodology in RS-11, (incorporated by reference, see § 434.701) or an equivalent approved method to determine the envelope air leakage. A standard blower door test is an acceptable technique to pressurize the building if the building is 5,000 ft 2 or less in area. The building's air handling system can be used to pressurize the building if the building is larger than 5,000 ft 2. The following test conditions shall be:

(a) The measured envelope air leakage shall not exceed 1.57 pounds per square foot of wall area at a pressure difference of 0.3 inches water.

(b) At the time of testing, all windows and outside doors shall be installed and closed, all interior doors shall be open, and all air handlers and dampers shall be operable. The building shall be unoccupied.

(c) During the testing period, the average wind speed during the test shall be less than 6.6 feet per second, the average outside temperature greater than 59 °F, and the average inside-outside temperature difference is less than 41 °F.

402.2.2.5 Moisture Migration. The building envelope shall be designed to limit moisture migration that leads to deterioration in insulation or equipment performance as determined by the following construction practices:

(a) A vapor retarder shall be installed to retard, or slow down the rate of water vapor diffusion through the building envelope. The position of the vapor retarder shall be determined taking into account local climate and indoor humidity levels. The methodologies presented in Chapter 20 of RS-4 (incorporated by reference, see § 434.701) shall be used to determine temperature and water vapor profiles through the envelope systems to assess the potential for condensation within the envelope and to determine the position of the vapor retarder within the envelope system.

(b) The vapor retarder shall be installed over the entire building envelope.

(c) The perm rating requirements of the vapor retarder shall be determined using the methodologies contained in Chapter 20 of RS-4, (incorporated by reference, see § 434.701) and shall take into account local climate and indoor humidity level. The vapor retarder shall have a performance rating of 1 perm or less.

402.3 Thermal Performance Criteria.

402.3.1 Roofs; Floors and Walls Adjacent to Unconditioned Spaces. The area weighted average thermal transmittance of roofs and also of floors and walls adjacent to unconditioned spaces shall not exceed the criteria in Table 402.3.1a. Exceptions are as follows: Skylights for which daylight credit is taken may be excluded from the calculations of the roof assembly Uor if all of the following conditions are met:

(a) The opaque roof thermal transmittance is less than the criteria in Table 402.3.1b.

(b) Skylight areas, including framing, as a percentage of the roof area do not exceed the values specified in Table 402.3.1b. The maximum skylight area from Table 402.3.1b may be increased by 50% if a shading device is used that blocks over 50% of the solar gain during the peak cooling design condition. For shell buildings, the permitted skylight area shall be based on a light level of 30 foot candles and a lighting power density (LPD) of less than 1.0 w/ft 2. For speculative buildings, the permitted skylight area shall be based on the unit lighting power allowance from Table 401.3.2a and an illuminance level as follows: for LPD <1.0, use 30 footcandles; for 1.0 <LPD <2.5, use 50 footcandles; and for LPD ≥2.5, use 70 footcandles.

(c) All electric lighting fixtures within daylighted zones under skylights are controlled by automatic daylighting controls.

(d) The Uo of the skylight assembly including framing does not exceed____________Btu/(h·ft 2·°F) [Use 0.70 for ≤8000 HDD65 and 0.45 for >8000 HDD65 or both if the jurisdiction includes cities that are both below and above 8000 HDD65.]

(e) Skylight curb U-value does not exceed 0.21 Btu/(h·ft 2·°F).

(f) The infiltration coefficient of the skylights does not exceed 0.05 cfm/ft 2.

402.3.2 Below-Grade Walls and Slabs-on-Grade. The thermal resistance (R-value) of insulation for slabs-on-grade, or the overall thermal resistance of walls in contact with the earth, shall be equal to or greater than the values in Table 402.3.2.

402.4 Exterior Walls. Exterior walls shall comply with either 402.4.1 or 402.4.2.

402.4.1 Prescriptive Criteria. (a) The exterior wall shall be designed in accordance with subsections 402.4.1.1 and 402.4.1.2. When the internal load density range is not known, the 0-1.50 W/ft 2 range shall be used for residential, hotel/motel guest rooms, or warehouse occupancies; the 3.01-3.50 w/ft 2 range shall be used for retail stores smaller than 2,000 ft 2 and technical and vocational schools smaller than 10,000 ft 2; and the 1.51-3.00 W/ft 2 range shall be used for all other occupancies and building sizes. When the building envelope is designed or constructed prior to knowing the building occupancy type, an internal load density of ______ W/ft 2 shall be used. [Use 3.0 W/ft 2 for HDD65 <3000, 2.25 W/ft 2 for 3000 <HDD65 <6000, and 1.5 W/ft 2 for HDD65 >6000.]

(b) When more than one condition exists, area weighted averages shall be used. This requirement shall apply to all thermal transmittances, shading coefficients, projection factors, and internal load densities rounded to the same number of decimal places as shown in the respective table.

402.4.1.1 Opaque Walls. The weighted average thermal transmittance (U-value) of opaque wall elements shall be less than the values in Table 402.4.1.1. For mass walls (HC ≥5), criteria are presented for low and high window/wall ratios and the criteria shall be determined by interpolating between these values for the window/wall ratio of the building.

402.4.1.2 Fenestration. The design of the fenestration shall meet the criteria of Table 402.4.1.2. When the fenestration columns labeled “Perimeter Daylighting” are used, automatic daylighting controls shall be installed in the perimeter daylighted zones of the building. These daylighting controls shall be capable of reducing electric lighting power to at least 50% of full power. Only those shading or lighting controls for perimeter daylighting that are shown on the plans shall be considered. The column labeled “VLT >= SC” shall be used only when the shading coefficient of the glass is less than its visible light transmittance.

Appendix A

The example Alternate Component Package tables illustrate the requirements of subsections 434.301.1, 434.402.3.1, 434.402.3.2, 434.402.4.1.1 and 434.402.4.1.2. Copies of specific tables contained in this appendix A can be obtained from the Energy Code for Federal Commercial Buildings, Docket No. EE-RM-79-112-C, EE-43, Office of Building Research and Standards, U.S. Department of Energy, Room 1J-018, 1000 Independence Avenue, SW., Washington, DC 20585, (202) 586-9127.

402.4.2 System Performance Criteria. The cumulative annual energy flux attributable to thermal transmittance and solar gains shall be less than the criteria determined using the ENVSTD24 computer program in Standard 90.1-1989, or the equations in RS-1, (incorporated by reference, see § 434.701) Attachment 8-B. The cumulative annual energy flux shall be calculated using the ENVSTD24 computer program or the equations in RS-1, (incorporated by reference, see § 434.701) Attachment 8-B.

402.4.2.1 Equipment Power Density (EQUIP). The equipment power density used in the ENVSTD24 computer program shall use the actual equipment power density from the building plans and specifications or be taken from Table 402.4.2 using the column titled “Default Adjusted Equipment Power Density” or calculated for the building using the procedures of RS-1. (incorporated by reference, see § 434.701). The program limits consideration of the equipment power density to a maximum of 1 W/ft 2.

402.4.2.2 Lighting Power Density (LIGHTS). The lighting power density used in the ENVSTD24 computer program shall use the actual lighting power density from the building plans and specifications or the appropriate value from Tables 401.3.2a, b, c, or d.

402.4.2.3 Daylighting Control Credit Fraction (DLCF). When the daylighting control credit fraction is other than zero, automatic daylighting controls shall be installed in the appropriate perimeter zones(s) of the building to justify the credit.

Mechanical systems and equipment used to provide heating, ventilating, and air conditioning functions as well as additional functions not related to space conditioning, such as, but not limited to, freeze protection in fire projection systems and water heating, shall meet the requirements of this section.

403.1 Mechanical Equipment Efficiency. When equipment shown in Tables 403.1a through 403.1f is used, it shall have a minimum performance at the specified rating conditions when tested in accordance with the specified reference standard. The reference standards listed in Tables 403.1a through 403.1f are incorporated by reference, see § 434.701. Omission of minimum performance requirements for equipment not listed in Tables 403.1a through 403.1f does not preclude use of such equipment.

403.1.1 Where multiple rating conditions and/or performance requirements are provided, the equipment shall satisfy all stated requirements.

403.1.2 Equipment used to provide water heating functions as part of a combination integrated system shall satisfy all stated requirements for the appropriate space heating or cooling category.

403.1.3 The equipment efficiency shall be supported by data furnished by the manufacturer or shall be certified under a nationally recognized certification program or rating procedure.

403.1.4 Where components, such as indoor or outdoor coils, from different manufacturers are used, the system designer shall specify component efficiencies whose combined efficiency meets the standards herein.

403.2 HVAC Systems.

403.2.1 Load Calculations. Heating and cooling system design loads for the purpose of sizing systems and equipment shall be determined in accordance with the procedures described in RS-1 (incorporated by reference, see § 434.701) using the design parameters specified in subpart C of this part.

403.2.2 Equipment and System Sizing. Heating and cooling equipment and systems shall be sized to provide no more than the loads calculated in accordance with subsection 403.2.1. A single piece of equipment providing both heating and cooling must satisfy this provision for one function with the other function sized as small as possible to meet the load, within available equipment options. Exceptions are as follows:

(a) When the equipment selected is the smallest size needed to meet the load within available options of the desired equipment line.

(b) Standby equipment provided with controls and devices that allow such equipment to operate automatically only when the primary equipment is not operating.

(c) Multiple units of the same equipment type with combined capacities exceeding the design load and provided with controls that sequence or otherwise optimally control the operation of each unit based on load.

403.2.3 Separate Air Distribution System. Zones with special process temperature and/or humidity requirements shall be served by air distribution systems separate from those serving zones requiring only comfort conditions or shall include supplementary provisions so that the primary systems may be specifically controlled for comfort purposes only. Exceptions: Zones requiring only comfort heating or comfort cooling that are served by a system primarily used for process temperature and humidity control need not be served by a separate system if the total supply air to these comfort zones is no more than 25% of the total system supply air or the total conditioned floor area of the zones is less than 1000 ft2.

403.2.4 Ventilation and Fan System Design. Ventilation systems shall be designed to be capable of reducing the supply of outdoor air to the minimum ventilation rates required by Section 6.1.3 of RS-41 (incorporated by reference, see § 434.701) through the use of return ducts, manually or automatically operated control dampers, fan volume controls, or other devices. Exceptions are as follows: Minimum outdoor air rates may be greater if:

(a) Required to make up air exhausted for source control of contaminants such as in a fume hood.

(b) Required by process systems.

(c) Required to maintain a slightly positive building pressure. For this purpose, minimum outside air intake may be increased up to no greater than 0.30 air changes per hour in excess of exhaust quantities.

403.2.4.1 Ventilation controls for variable or high occupancy areas. Systems with design outside air capacities greater than 3,000 cfm serving areas having an average design occupancy density exceeding 100 people per 1,000 ft 2 shall include means to automatically reduce outside air intake to the minimum values required by RS-41 (incorporated by reference, see § 434.701) during unoccupied or low-occupancy periods. Outside air shall not be reduced below 0.14 cfm/ft 2. Outside air intake shall be controlled by one or more of the following:

(a) A clearly labeled, readily accessible bypass timer that may be used by occupants or operating personnel to temporarily increase minimum outside air flow up to design levels.

(b) A carbon dioxide (CO2) control system having sensors located in the spaces served, or in the return air from the spaces served, capable of maintaining space CO2 concentrations below levels recommended by the manufacturer, but no fewer than one sensor per 25,000 ft 2 of occupied space shall be provided.

(c) An automatic timeclock that can be programmed to maintain minimum outside air intake levels commensurate with scheduled occupancy levels.

(d) Spaces equipped with occupancy sensors.

403.2.4.2 Ventilation Controls for enclosed parking garages. Garage ventilation fan systems with a total design capacity greater than 30,000 cfm shall have automatic controls that stage fans or modulate fan volume as required to maintain carbon monoxide (CO) below levels recommended in RS-41.

403.2.4.3 Ventilation and Fan Power. The fan system energy demand of each HVAC system at design conditions shall not exceed 0.8 W/cfm of supply air for constant air volume systems and 1.25 W/cfm of supply air for variable-air-volume (VAV) systems. Fan system energy demand shall not include the additional power required by air treatment or filtering systems with pressure drops over 1 in. w.c. Individual VAV fans with motors 75 hp and larger shall include controls and devices necessary for the fan motor to demand no more than 30 percent of design wattage at 50 percent of design air volume, based on manufacturer's test data. Exceptions are as follows:

(a) Systems with total fan system motor horsepower of 10 hp or less.

(b) Unitary equipment for which the energy used by the fan is considered in the efficiency ratings of subsection 403.1.

403.2.5 Pumping System Design. HVAC pumping systems used for comfort heating and/or comfort air conditioning that serve control valves designed to modulate or step open and closed as a function of load shall be designed for variable fluid flow and capable of reducing system flow to 50 percent of design flow or less. Exceptions are as follows:

(a) Systems where a minimum flow greater than 50% of the design flow is required for the proper operation of equipment served by the system, such as chillers.

(b) Systems that serve no more than one control valve.

(c) Systems with a total pump system horse power ≤10 hp.

(d) Systems that comply with subsection 403.2.6.8 without exception.

403.2.6 Temperature and Humidity Controls.

403.2.6.1 System Controls. Each heating and cooling system shall include at least one temperature control device.

403.2.6.2 Zone Controls. The supply of heating and cooling energy to each zone shall be controlled by individual thermostatic controls responding to temperature within the zone. For the purposes of this section, a dwelling unit is considered a zone. Exceptions are as follows: Independent perimeter systems that are designed to offset building envelope heat losses or gains or both may serve one or more zones also served by an interior system when the perimeter system includes at least one thermostatic control zone for each building exposure having exterior walls facing only one orientation for at least 50 contiguous ft and the perimeter system heating and cooling supply is controlled by thermostat(s) located within the zone(s) served by the system.

403.2.6.3 Zone Thermostatic Control Capabilities. Where used to control comfort heating, zone thermostatic controls shall be capable of being set locally or remotely by adjustment or selection of sensors down to 55 °F or lower. Where used to control comfort cooling, zone thermostatic controls shall be capable of being set locally or remotely by adjustment or selection of sensors up to 85 °F or higher. Where used to control both comfort heating and cooling, zone thermostatic controls shall be capable of providing a temperature range or deadband of at least 5 °F within which the supply of heating and cooling energy to the zone is shut off or reduced to a minimum. Exceptions are as follows:

(a) Special occupancy or special usage conditions approved by the building official or

(b) Thermostats that require manual changeover between heating and cooling modes.

403.2.6.4 Heat Pump Auxiliary Heat. Heat pumps having supplementary electric resistance heaters shall have controls that prevent heater operation when the heating load can be met by the heat pump. Supplemental heater operation is permitted during outdoor coil defrost cycles not exceeding 15 minutes.

403.2.6.5 Humidistats. Humidistats used for comfort purposes shall be capable of being set to prevent the use of fossil fuel or electricity to reduce relative humidity below 60% or increase relative humidity above 30%.

403.2.6.6 Simultaneous Heating and Cooling. Zone thermostatic and humidistatic controls shall be capable of operating in sequence the supply of heating and cooling energy to the zone. Such controls shall prevent: Reheating; recooling; mixing or simultaneous supply of air that has been previously mechanically heated and air that has been previously cooled, either by mechanical refrigeration or by economizer systems; and other simultaneous operation of heating and cooling systems to the same zone. Exceptions are as follows:

(a) Variable-air-volume systems that, during periods of occupancy, are designed to reduce the air supply to each zone to a minimum before heating, recooling, or mixing takes place. This minimum volume shall be no greater than the larger of 30% of the peak supply volume, the minimum required to meet minimum ventilation requirements of the Federal agency. (0.4 cfm/ft 2 of zone conditioned floor area, and 300 cfm).

(b) Zones where special pressurization relationships or cross-contamination requirements are such that variable-air-volume systems are impractical, such as isolation rooms, operating areas of hospitals and clean rooms.

(c) At least 75% of the energy for reheating or for providing warm air in mixing systems is provided from a site-recovered or site-solar energy source.

(d) Zones where specified humidity levels are required to satisfy process needs, such as computer rooms and museums.

(e) Zones with a peak supply air quantity of 300 cfm or less.

403.2.6.7 Temperature Reset for Air Systems. Air systems supplying heated or cooled air to multiple zones shall include controls that automatically reset supply air temperatures by representative building loads or by outside air temperature. Temperature shall be reset by at least 25% of the design supply air to room air temperature difference. Zones that are expected to experience relatively constant loads, such as interior zones, shall be designed for the fully reset supply temperature. Exception are as follows: Systems that comply with subsection 403.2.6.6 without using exceptions (a) or (b).

403.2.6.8 Temperature Reset for Hydronic Systems. Hydronic systems of at least 600,000 Btu/hr design capacity supplying heated and/or chilled water to comfort conditioning systems shall include controls that automatically reset supply water temperatures by representative building loads (including return water temperature) or by outside air temperature. Temperature shall be reset by at least 25% of the design supply-to-return water temperature difference. Exceptions are as follows:

(a) Systems that comply with subsection 403.2.5 without exception or

(b) Where the design engineer certifies to the building official that supply temperature reset controls cannot be implemented without causing improper operation of heating, cooling, humidification, or dehumidification systems.

403.2.7 Off Hour Controls.

403.2.7.1 Automatic Setback or Shutdown Controls. HVAC systems shall be equipped with automatic controls capable of accomplishing a reduction of energy use through control setback or equipment shutdown. Exceptions are as follows:

(a) Systems serving areas expected to operate continuously or

(b) Equipment with full load demands not exceeding 2 kW controlled by readily accessible, manual off-hour controls.

403.2.7.2 Shutoff Dampers. Outdoor air supply and exhaust systems shall be provided with motorized or gravity dampers or other means of automatic volume shutoff or reduction. Exceptions are as follows:

(a) Systems serving areas expected to operate continuously.

(b) Individual systems which have a design airflow rate or 3000 cfm or less.

(c) Gravity and other non-electrical ventilation systems controlled by readily accessible, manual damper controls.

(d) Where restricted by health and life safety codes.

403.2.7.3 Zone Isolation systems that serve zones that can be expected to operate nonsimultaneously for more than 750 hours per year shall include isolation devices and controls to shut off or set back the supply of heating and cooling to each zone independently. Isolation is not required for zones expected to operate continuously or expected to be inoperative only when all other zones are inoperative. For buildings where occupancy patterns are not known at the time of system design, such as speculative buildings, the designer may predesignate isolation areas. The grouping of zones on one floor into a single isolation area shall be permitted when the total conditioned floor area does not exceed 25,000 ft 2 per group.

403.2.8 Economizer Controls.

403.2.8.1 Each fan system shall be designed and capable of being controlled to take advantage of favorable weather conditions to reduce mechanical cooling requirements. The system shall include either: A temperature or enthalpy air economizer system that is capable of automatically modulating outside air and return air dampers to provide up to 85% of the design supply air quantity as outside air, or a water economizer system that is capable of cooling supply air by direct and/or indirect evaporation and is capable of providing 100% of the expected system cooling load at outside air temperatures of 50 °F dry-bulb/45 °F wet-bulb and below. Exceptions are as follows:

(a) Individual fan-cooling units with a supply capacity of less than 3000 cfm or a total cooling capacity less than 90,000 Btu/h.

(b) Systems with air-cooled or evaporatively cooled condensers that include extensive filtering equipment provided in order to meet the requirements of RS-41 (incorporated by reference, see § 434.701).

(c) Systems with air-cooled or evaporatively cooled condensers where the design engineer certifies to the building official that use of outdoor air cooling affects the operation of other systems, such as humidification, dehumidification, and supermarket refrigeration systems, so as to increase overall energy usage.

(d) Systems that serve envelope-dominated spaces whose sensible cooling load at design conditions, excluding transmission and infiltration loads, is less than or equal to transmission and infiltration losses at an outdoor temperature of 60 °F.

(e) Systems serving residential spaces and hotel or motel rooms.

(f) Systems for which at least 75% of the annual energy used for mechanical cooling is provided from a site-recovered or site-solar energy source.

(g) The zone(s) served by the system each have operable openings (windows, doors, etc.) with an openable area greater than 5% of the conditioned floor area. This applies only to spaces open to and within 20 ft of the operable openings. Automatic controls shall be provided that lock out system mechanical cooling to these zones when outdoor air temperatures are less than 60 °F.

403.2.8.2 Economizer systems shall be capable of providing partial cooling even when additional mechanical cooling is required to meet the remainder of the cooling load. Exceptions are as follows:

(a) Direct-expansion systems may include controls to reduce the quantity of outdoor air as required to prevent coil frosting at the lowest step of compressor unloading. Individual direct-expansion units that have a cooling capacity of 180,000 Btu/h or less may use economizer controls that preclude economizer operation whenever mechanical cooling is required simultaneously.

(b) Systems in climates with less than 750 average operating hours per year between 8 a.m. and 4 p.m. when the ambient dry-bulb temperatures are between 55 °F and 69 °F inclusive.

403.2.8.3 System design and economizer controls shall be such that economizer operation does not increase the building heating energy use during normal operation.

403.2.9 Distribution System Construction and Insulation.

403.2.9.1 Piping Insulation. All HVAC system piping shall be thermally insulated in accordance with Table 403.2.9.1. Exceptions are as follows:

(a) Factory-installed piping within HVAC equipment tested and rated in accordance with subsection 403.1.

(b) Piping that conveys fluids that have a design operating temperature range between 55 °F and 105 °F.

(c) Piping that conveys fluids that have not been heated or cooled through the use of fossil fuels or electricity.

403.2.9.2 Duct and Plenum Insulation. All supply and return air ducts and plenums installed as part of an HVAC air distribution system shall be thermally insulated in accordance with Table 403.2.9.1. Exceptions are as follows:

(a) Factory-installed plenums, casings, or ductwork furnished as a part of the HVAC equipment tested and rated in accordance with subsection 403.1

(b) Ducts within the conditioned space that they serve. (incorporated by reference, see § 434.701)ca a06oc0.186

403.2.9.3 Duct and Plenum Construction. All air-handling ductwork and plenums shall be constructed and erected in accordance with RS-34, RS-35, and RS-36 (incorporated by reference, see § 434.701). Where supply ductwork and plenums designed to operate at static pressures from 0.25 in. wc to 2 in. wc, inclusive, are located outside of the conditioned space or in return plenums, joints shall be sealed in accordance with Seal Class C as defined in RS-34 (incorporated by reference, see § 434.701). Pressure sensitive tape shall not be used as the primary sealant where such ducts are designed to operate at static pressures of 1 in. wc, or greater.

403.2.9.3.1 Ductwork designed to operate at static pressures in excess of 3 in. wc shall be leak-tested in accordance with Section 5 of RS-35, (incorporated by reference, see § 434.701), or equivalent. Test reports shall be provided in accordance with Section 6 of RS-35, (incorporated by reference, see § 434.701)m or equivalent. The tested duct leakage class at a test pressure equal to the design duct pressure class rating shall be equal to or less than leakage Class 6 as defined in Section 4.1 of RS-35 (incorporated by reference, see § 434.701). Representative sections totaling at least 25% of the total installed duct area for the designated pressure class shall be tested.

403.2.10 Completion.

403.2.10.1 Manuals. Construction documents shall require an operating and maintenance manual provided to the Federal Agency. The manual shall include, at a minimum, the following:

(a) Submittal data stating equipment size and selected options for each piece of equipment requiring maintenance, including assumptions used in outdoor design calculations.

(b) Operating and maintenance manuals for each piece of equipment requiring maintenance. Required maintenance activity shall be specified.

(c) Names and addresses of at least one qualified service agency to perform the required periodic maintenance shall be provided.

(d) HVAC controls systems maintenance and calibration information, including wiring diagrams, schematics, and control sequence descriptions. Desired or field determined setpoints shall be permanently recorded on control drawings, at control devices, or, for digital control systems, in programming comments.

(e) A complete narrative, prepared by the designer, of how each system is intended to operate shall be included with the construction documents.

403.2.10.2 Drawings. Construction documents shall require that within 30 days after the date of system acceptance, record drawings of the actual installation be provided to the Federal agency. The drawings shall include details of the air barrier installation in every envelope component, demonstrating continuity of the air barrier at all joints and penetrations.

403.2.10.3 Air System Balancing. Construction documents shall require that all HVAC systems be balanced in accordance with the industry accepted procedures (such as National Environmental Balancing Bureau (NEBB) Procedural Standards, Associated Air Balance Council (AABC) National Standards, or ANSI/ASHRAE Standard 111). Air and water flow rates shall be measured and adjusted to deliver final flow rates within 10% of design rates, except variable flow distribution systems need not be balanced upstream of the controlling device (VAV box or control valve).

403.2.10.3.1 Construction documents shall require a written balance report be provided to the Federal agency for HVAC systems serving zones with a total conditioned area exceeding 5,000 ft 2.

403.2.10.3.2 Air systems shall be balanced in a manner to first minimize throttling losses, then fan speed shall be adjusted to meet design flow conditions or equivalent procedures. Exceptions are as follows: Damper throttling may be used for air system balancing;

(a) With fan motors of 1 hp (0.746 kW) or less, or

(b) Of throttling results in no greater than 1/3 hp (0.248 kW) fan horsepower draw above that required if the fan speed were adjusted.

403.2.10.4 Hydronic System Balancing. Hydronic systems shall be balanced in a manner to first minimize throttling losses; then the pump impeller shall be trimmed or pump speed shall be adjusted to meet design flow conditions. Exceptions are as follows:

(a) Pumps with pump motors of 10 hp (7.46 kW) or less.

(b) If throttling results in no greater than 3 hp (2.23 kW) pump horsepower draw above that required if the impeller were trimmed.

(c) To reserve additional pump pressure capability in open circuit piping systems subject to fouling. Valve throttling pressure drop shall not exceed that expected for future fouling.

403.2.10.5 Control System Testing. HVAC control systems shall be tested to assure that control elements are calibrated, adjusted, and in proper working condition. For projects larger than 50,000 ft2 conditioned area, detailed instructions for commissioning HVAC systems shall be provided by the designer in plans and specifications.

404.1 Service Water Heating Equipment Efficiency. Equipment must satisfy the minimum performance efficiency specified in Table 404.1 when tested in accordance with RS-37, RS-38, or RS-39 (incorporated by reference, see § 434.701). Omission of equipment from Table 404.1 shall not preclude the use of such equipment. Service water heating equipment used to provide additional function of space heating as part of a combination (integrated) system shall satisfy all stated requirements for the service water heating equipment. All gas-fired storage water heaters that are not equipped with a flue damper and use indoor air for combustion or draft hood dilution and that are installed in a conditioned space, shall be equipped with a vent damper listed in accordance with RS-42 (incorporated by reference, see § 434.701). Unless the water heater has an available electrical supply, the installation of such a vent damper shall not require an electrical connection.

404.1.1 Testing Electric and Oil Storage Water Heaters for Standby Loss.

(a) When testing an electric storage water heater, the procedures of Z21.10.3-1990 (RS-39, incorporated by reference, see § 434.701), Section 2.9, shall be used. The electrical supply voltage shall be maintained with ±1% of the center of the voltage range specified on the water heater nameplate. Also, when needed for calculations, the thermal efficiency (Et) shall be 98%. When testing an oil-fired water heater, the procedures of Z21.10.3-1990 (RS-39 incorporated by reference, see § 434.701), Sections 2.8 and 2.9, shall be used.

(b) The following modifications shall be made: A vertical length of flue pipe shall be connected to the flue gas outlet of sufficient height to establish the minimum draft specified in the manufacturer's installation instructions. All measurements of oil consumption shall be taken by instruments with an accuracy of ±1% or better. The burner rate shall be adjusted to achieve an hourly Btu input rate within ±2% of the manufacturer's specified input rate with the CO2 reading as specified by the manufacturer with smoke no greater than 1 and the fuel pump pressure within ±1% of the manufacturer's specification.

404.1.2 Unfired Storage Tanks. The heat loss of the tank surface area Btu/(h·ft 2) shall be based on an 80 °F water-air temperature difference.

404.1.3 Storage Volume Symbols in Table 404.1. The symbol “V” is the rated storage volume in gallons as specified by the manufacturer. The symbol “VT” is the storage volume in gallons as measured during the test to determine the standby loss. VT may differ from V, but it is within tolerances allowed by the applicable Z21 and Underwriters Laboratories standards. Accordingly, for the purpose of estimating the standby loss requirement using the rated volume shown on the rating plate, VT should be considered as no less than 0.95V for gas and oil water heaters and no less than 0.90V for electric water heaters.

404.1.4 Electric Water Heaters. In applications where water temperatures not greater than 145 °F are required, an economic evaluation shall be made on the potential benefit of using an electric heat pump water heater(s) instead of an electric resistance water heater(s). The analysis shall compare the extra installed costs of the heat pump unit with the benefits in reduced energy costs (less increased maintenance costs) over the estimated service life of the heat pump water heater. Exceptions are as follows: Electric water heaters used in conjunction with site-recovered or site-solar energy sources that provide 50% or more of the water heating load or off-peak heating with thermal storage.

404.2 Service Hot Water Piping Insulation. Circulating system piping and noncirculating systems without heat traps, the first eight feet of outlet piping from a constant-temperature noncirculating storage system, and the inlet pipe between the storage tank and a heat trap in a noncirculating storage system shall meet the provisions of subsection 403.2.9.

404.2.1 Vertical risers serving storage water heaters not having an integral heat trap and serving a noncirculating system shall have heat traps on both the inlet and outlet piping as close as practical to the water heater.

404.3 Service Water Heating System Controls. Temperature controls that allow for storage temperature adjustment from 110 °F to a temperature compatible with the intended use shall be provided in systems serving residential dwelling units and from 90 °F for other systems. When designed to maintain usage temperatures in hot water pipes, such as circulating hot water systems or heat trace, the system shall be equipped with automatic time switches or other controls that can be set to turn off the system.

404.3.1 The outlet temperature of lavatory faucets in public facility restrooms shall be limited to 110 °F.

404.4 Water Conservation. Showerheads and lavatory faucets must meet the requirements of 10 CFR 430.32 (o)-(p).

404.4.1 Lavatory faucets in public facility restrooms shall be equipped with a foot switch, occupancy sensor, or similar device or, in other than lavatories for physically handicapped persons, limit water delivery to 0.25 gal/cycle.

404.5 Swimming Pools. All pool heaters shall be equipped with a readily accessible on-off switch.

404.5.1 Time switches shall be installed on electric heaters and pumps. Exceptions are as follows:

(a) Pumps required to operate solar or heat recovery pool heating systems.

(b) Where public health requirements require 24-hour pump operation.

404.5.2 Heated swimming pools shall be equipped with pool covers. Exception: When over 70% of the annual energy for heating is obtained from a site-recovered or site-solar energy source.

404.6 Combined Service Water Heating and Space Heating Equipment. A single piece of equipment shall not be used to provide both space heating and service water heating. Exceptions are as follows:

(a) The energy input or storage volume of the combined boiler or water heater is less than twice the energy input or storage volume of the smaller of the separate boilers or water heaters otherwise required or

(b) The input to the combined boiler is less than 150,000 Btuh.