Presentation on theme: "U.S. Department of Energy Building Energy Codes Program"— Presentation transcript:
1U.S. Department of Energy Building Energy Codes Program Residential Requirements of the 2009 International Energy Conservation CodeU.S. Department of Energy Building Energy Codes ProgramPNNL-SA-65859
2What’s Changed Since IECC 2006? Stringency – some key differencesNew requirementsBuilding envelope tightnessDuct testingLighting equipmentPool controls and coversSnow melt controlsMoisture control requirements moved to IRCNo mechanical trade-offs allowed
4Residential Chapter Structure of the IECC Chapter 1 Administrative Chapter 2 DefinitionsChapter 3 Climate ZonesChapter 4 Residential Energy EfficiencyChapter 5 Commercial Energy EfficiencyChapter Referenced StandardsResidentialChapter
5Overview of Residential Code Requirements Focus is on building envelopeCeilings, walls, windows, floors, foundationsSets insulation levels, window U-factors and solar heat gain coefficientsInfiltration control - caulk and seal to prevent air leaksDucts – seal and insulateLimited space heating, air conditioning, and water heating requirementsFederal law sets most equipment efficiency requirements, not the I-codesNo appliance requirementsLighting equipment – 50% of lamps to be high-efficacy lamps
6Additions, Alterations, Renovations, Repairs Conform as relates to new constructionUnaltered portions(s) do not need to complyAdditions can comply alone or in combination with existing buildingExceptionsStorm windows over existing fenestrationGlass only replacementsExposed, existing ceiling, wall or floor cavities if already filled with insulationWhere existing roof, wall or floor cavity isn’t exposedReroofing for roofs where neither sheathing nor insulation exposedInsulate above or below the sheathingRoofs without insulation in the cavitySheathing or insulation is exposed
7Treat as a stand-alone building AdditionsTreat as a stand-alone buildingAdditions must meet the prescriptive requirements in Table1. Treat the addition as a stand-alone building and ignore the common walls between the existing building and the addition.Combine the existing building with the addition and bring the whole building to compliance. Compliance can be harder to achieve if the existing building is quite old.N
8Additions, Alterations, Renovations, Repairs Roof ReplacementWhere the roof of an existing building is being replaced and the roof is a component of the thermal envelope of a building being regulated by the code, and the R-Value of the existing roof insulation is less than 30, insulation shall be added to achieve R-30. (CABQ Code based on 2006 IECC)2009 IECC - None, for new building R-38NM 2009 Energy Code - None, for new building R-38ASHRAE None , for new building R-49
9IECC Compliance - Three Options PrescriptiveR-valuesU-Factor and “UA” AlternativesSimulated Performance(software)U-factorTotal Building UASimulated Performance Alternative405
10Code Compliance Alternate Method Above-code programs. One and two-family dwellings and townhomes designed to obtain LEED Silver or Build Green New Mexico Silver certification are deemed to meet the greenhouse gas reduction codes of the City of Albuquerque and to be in compliance with this code2009 IECC – Above-code programs authorized in SectionThere are mandatory envelope requirements (design must meet these requirements regardless of location) which include moisture and infiltration control and duct insulation. Other envelope requirements such as insulation values and window efficiency are based on the climate of the project location.
11INDEPENDENT THIRD PARTY INSPECTIONS AND TESTS Requires inspections and tests under direct supervision of a RESNET Certified Home Energy RaterThermal Bypass InspectionDuct Leakage TestsBuilding Envelope Leakage Test2009 IECC – Certificate of Inspection Thermal Bypass Test or InspectionNM 2009 Energy Code Certificate of Inspection, Thermal Bypass InspectionThere are mandatory envelope requirements (design must meet these requirements regardless of location) which include moisture and infiltration control and duct insulation. Other envelope requirements such as insulation values and window efficiency are based on the climate of the project location.
12Climate-Specific Requirements FoundationsBasementsSlabsCrawlspacesAbove grade wallsSkylights, windows, and doorsRoofsSolar Heat Gain Coefficient in warm climatesUniversal Requirements (apply everywhere):Duct insulation and sealingInfiltration controlIncluding recessed cansThere are mandatory envelope requirements (design must meet these requirements regardless of location) which include moisture and infiltration control and duct insulation. Other envelope requirements such as insulation values and window efficiency are based on the climate of the project location.
13Insulation and Fenestration Requirements by Climate Zone Table Insulation and Fenestration Requirements by Componentaa. R-values are minimums, U-factors and SHGC are maximums, R-19 batts compressed into a nominal 2 x 6 framing cavity such that the R-value is reduced by R-1 or more shall be marked with the compressed batt R-value in addition to the full thickness R-value.b. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.c. “15/19” means R-15 continuous insulated sheathing on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. “15/19” shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulated sheathing on the interior or exterior of the home. “10/13” means R-10 continuous insulated sheathing on the interior or exterior of the home or R-13 cavity insulation at the interior of the basement wall.d. R-5 shall be added to the required slab edge R-values for heated slabs. Insulation depth shall be the depth of the footing or 2 feet, whichever is less in Zones 1 through 3 for heated slabs.e. There are no SHGC requirements in the Marine Zone.f. Basement wall insulation is not required in warm-humid locations as defined by Figure and Tableg. Or insulation sufficient to fill the framing cavity, R-19 minimum.h. “13+5” means R-13 cavity insulation plus R-5 insulated sheathing. If structural sheathing covers 25 percent or less of the exterior, insulating sheathing is not required where structural sheathing is used. If structural sheathing covers more than 25 percent of exterior, structural sheathing shall be supplemented with insulated sheathing of at least R-2.i. The second R-value applies when more than half the insulation is on the interior of the mass wall.j. For impact rated fenestration complying with Section R of the IRC or Section of the IBC, maximum U-factor shall be 0.75 in Zone 2 and 0.65 in Zone 3.
15U-Factor Requirements by Climate Zone Table Equivalent U-FactorsaNote: SHGC values are in Table and must be met regardless of the this table.Lets take a look at each one of these components in the order of this table starting with fenestration.Note that this table applies to assemblies whereas the previous (R-value) table applies to insulation only.Footnote d which appears in the printed 2009 IECC was removeda. Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.b. When more than half the insulation is on the interior, the mass wall U-factors shall be a maximum of 0.17 in Zone 1, 0.14 in Zone 2, 0.12 in Zone 3, 0.10 in Zone 4 except Marine, and the same as the frame wall U-factor in Marine Zone 4 and Zones 5 through 8.c. Basement wall U-factor of in warm-humid locations as defined by Figure and Table
17Mandatory Requirements Building Envelope Air leakageRecessed lightingMaximum fenestration U-factor and SHGCFireplaces
18Mandatory Requirements Air Leakage ControlMandatory RequirementsBuilding envelopeSealed with caulking materials orClosed with gasketing systemsJoints and seams sealed or taped or covered with a moisture vapor-permeable wrapping materialThe sealing methods between dissimilar materials shall allow for differential expansion and contraction.
19Areas for Air Leakage (Infiltration) Windows and doorsBetween sole platesFloors and exterior wall panelsPlumbingElectricalService access doors or hatchesRecessed light fixturesRim joist junctionThere is no specific code language that precisely dictates how a leak should be sealed or how to judge the quality of a seal.There are several places where air leakage can occur:Site-built windows, doors, and skylightsOpenings between window and door assemblies and their respective jambs and framingUtility penetrationsDropped ceilings or chases adjacent to the thermal envelopeKnee wallsBehind stairwells on exterior wallsWalls and ceilings separating a garage from conditioned spacesBehind tubs and showers on exterior wallsCommon walls between dwelling unitsAttic access hatches
20Air Sealing and Insulation 2 options to demonstrate complianceWhen tested air leakage is <7 ACH when tested with a blower door at pressure of 33.5 psf (Section )Testing after rough in and installation of building envelope penetrationsWhen items listed in Table , applicable to the method of construction, are field verified (Section )
21Mechanical Systems & Equipment Equipment efficiency set by Federal law, not the I-Codes
22Mandatory Requirements Systems (Section 403) ControlsHeat pump supplementary heatDuctsSealing (Mandatory)Insulation (Prescriptive)HVAC piping insulationCirculating hot water systemsVentilationEquipment sizingSystems serving multiple dwelling unitsSnow melt controlsPools- Controls: at least one thermostat shall be provided for each separate heating and cooling system- Heat pump supplementary heat: heat pumps having supplementary electric resistance heat shall have control that except during defrost, prevent supplemental heat operation when the heat pump compressor can meet the heating load.
23Programmable Thermostat - Controls Mandatory RequirementsIf primary heating system is a forced-air furnaceAt least one programmable thermostat/dwelling unitCapability to set back or temporarily operate the system to maintain zone temperaturesdown to 55ºF (13ºC) orup to 85ºF (29ºC)Initially programmed with:heating temperature set point no higher than 70ºF (21ºC) andcooling temperature set point no lower than 78ºF (26ºC)
24Ducts Insulation (Prescriptive) Sealing (Mandatory) Ducts outside the building envelope: R-8All other ducts: R-6Sealing (Mandatory)Joints and seams shall comply with IRC, Section MBuilding framing cavities shall not be used as supply ductsNo Trade offs allowed for duct insulation.Exception: - ducts completely inside the building envelopeBuilding framing cavities shall not be used as supply ducts.
25Duct Insulation Requirements CABQ Code Exception: Ducts or portions thereof located completely inside the building thermal envelope2009 IECC Exception: Ducts or portions thereof located completely inside the building thermal envelopeNM 2009 Energy Code – Detailed specifications on location and R-value, even indirectly conditioned spaces (i.e. inside the building thermal envelope) required R = 3.5ASHRAE – Table C-10 detailed specifications on location and R-value either R=8 or R=6), the indirectly conditioned spaces require no insulation
26Mandatory Requirements Duct Tightness TestsMandatory RequirementsAll ducts, air handlers, filter boxes and building cavities used as ducts shall be sealed (Section )Duct tightness shall be verified by either −Post construction testLeakage to outdoors: ≤8 cfm/per 100 ft2 of conditioned floor area orTotal leakage: ≤12 cfm/per 100 ft2 of conditioned floor areatested at a pressure differential of 0.1 in w.g. (25Pa) across entire system, including manufacturer’s air handler enclosureAll register boots taped or otherwise sealedRough-in testTotal leakage ≤6 cfm/per 100 ft2 of conditioned floor areatested at a pressure differential of 0.1 in w.g. (25Pa) across roughed-in system, including manufacturer’s air handler enclosureall register boots taped or otherwise sealedif air handler not installed at time of testTotal air leakage ≤4 cfm/per 100 ft2Exceptions: Duct tightness test is not required if the air handler and all ducts are located within conditioned spaceOR
27Mandatory Requirements Piping InsulationMandatory RequirementsR-3 required onHVAC systemsException: Piping that conveys fluids between 55 and 105°FCABQ Code R=4 pipe 2” or less, R=6 piping > 2”2009 IECC R=3NM 2009 Energy Code R=2ASHRAE R=5 or greater depending on pipe diameter and temperatureCirculating hot water systems shall include an automatic or readily accessible manual switch that can turn off the hot water circulating pump when the system is not in use.Mandatory – no trade offs.
28Ventilation and Equipment Sizing Mandatory RequirementsVentilationOutdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operatingEquipment SizingIECC references Section M of the IRCLoad calculations determine the proper capacity (size) of equipmentGoal is big enough to ensure comfort but no biggerCalculations shall be performed in accordance with ACCA Manual J or other approved methodsEquipment sizing is a direct reference to the IRC.Oversized equipment has a higher initial cost, a higher operating cost, provides less comfort, and the short-cycling reduces the equipment life expectancy. Any one of these is a good reason not to oversize.Heating and cooling system design loads for the purpose of sizing systems and equipment shall be determined in accordance with the procedures described in the ACCA Manual J or an equivalent computation procedure.
29Fan Power LimitationCABQ Code Table Fan Performance Energy Star Label required2009 IECC = Table Fan Power LimitationNM 2009 Energy Code - meet Energy Star requirementsASHRAE % below ASHRAE 90.1 Requirements
30Roof Material Requirements 402,8 Roof ReflectanceReflective roof coverings that are Energy Star qualifiedLow slope roof – solar reflectance of 0.65Steep slope roof – solar reflectance of 0.25Exception, approved “green roofs”. (CABQ Code)2009 IECC = Specifies roof absorptance value 0.75NM 2009 Energy Code - not addressedASHRAE Solar Reflective Index requirementsLow slope roof – SRI = 78Steep slope roof – SRI = 29
31Lighting Equipment (Prescriptive) A minimum of 50 percent of the lamps in permanently installed lighting fixtures shall be high-efficacy lampsNM 2009 Energy Code also requires motion sensor, daylight sensor and/or timer shall be installed on at least 33% of the outdoor fiuxtures
32Simulated Performance Alternative Requires computer software with specified capabilities (local official may approve other tools)Includes both envelope and equipmentAllows greatest flexibility. Credits features such as:High efficiency furnaces, air-conditioners, etc.Tight ducts (must be leak tested) or hydronic systemsExterior shading, favorable orientation, thermal mass, SHGC, etc.Section 405 specifies “ground rules”These will generally be “hidden” in compliance software calculation algorithmsVery similar ground rules are used in home federal tax credits and ENERGY STAR Home guidelinesThe simulated performance alternative can be used for building designs that do comply with all the prescriptive requirements in Chapter 4 of the IECC. Under the simulated performance alternative, a “Proposed design” will comply with the code if the calculated annual energy cost is not greater than a similar building (the “Standard design”) designed in accordance with Chapter 4.The Proposed design uses the same energy sources, floor area, geometry, design conditions, occupancy, climate data, and usage schedule as the Standard design. Some energy-conserving strategies to improve the performance of the Proposed design include exterior shading of windows, passive solar design, thermal mass heat storage, improved thermal envelope, improved duct systems, reduced air infiltration, and high-efficiency heating, cooling, and water heating equipment.