Are You Ready for Solar-Ready? And Other Energy Code Updates

Transcription

1 Are You Ready for Solar-Ready? And Other Energy Code Updates May 9, 2018 Massachusetts Energy Code Technical Support Program 1 Who Is Mass Save? Mass Save is an initiative sponsored by Massachusetts gas and electric utilities and energy efficiency service providers, including -The Berkshire Gas Company -Cape Light Compact -Columbia Gas of Massachusetts -Eversource Energy -Liberty Utilities -National Grid -Unitil The Sponsors of Mass Save work closely with the Massachusetts Department of Energy Resources to provide a wide range of services, incentives, trainings, and information promoting energy efficiency that help residents and businesses manage energy use and related costs. 2 1

2 Continuing Education Eligible for Massachusetts Building Officials CEUs Attendance record will be submitted to OPSI 3 Agenda 9 th Edition Changes Residential Solar-ready provisions Significant changes from IECC 2012 to IECC 2015 with MA amendments Duct Insulation Duct leakage Insulation around hot water piping Mechanical Ventilation ERI Path Changes to 9th Edition Stretch Code Stretch Code for New Buildings Stretch Code for Existing Buildings 4 2

3 Presented by: Performance Systems Development Mike Turns, Senior Program Manager Rakesh Koti, Energy Code Specialist 5 ACEEE State Energy Efficiency Scorecard

4 MA Code Timeline 11 9 th Edition Concurrency & Changes Concurrency period: Oct 20, 2017 to Jan 1, Solar-ready roof-tops is the only change from 8 th Edition to 9 th Edition with respect to Residential Energy 12 4

5 Appendix U: Solar-Ready Provisions 2015 IECC Appendix RB SOLAR-READY PROVISIONS - DETACHED ONE- AND TWOFAMILY DWELLINGS, MULTIPLE SINGLE-FAMILY DWELLINGS Adopted by MA and replaced by Appendix U in 780 CMR 13 Appendix U: Solar-Ready Provisions Intent of Appendix U Ability to plan ahead for solar installation Solar-ready zones and roof load documentation helps solar contractors in installing solar PV Easy identification of unobstructed areas Easy identification of pathway to run conduits & wiring All the above will save a lot of money if the owner wants to install solar in the future. 14 5

6 Appendix U: Solar-Ready Provisions General AU General These provisions shall be applicable for new construction, except additions. AU102 GENERAL DEFINITIONS SOLAR-READY ZONE: A section or sections of the roof or building overhang designated and reserved for the future installation of a solar photovoltaic or solar thermal system. 15 Appendix U: Solar-Ready Provisions Scope AU103.2 General: Applies to new detached one-and two-family dwelling units and townhouses with: Not less than 600 sqft. of roof area oriented between 110 to 270 degrees of true north 16 6

7 Appendix U: Solar-Ready Provisions Scope 17 Appendix U: Solar-Ready Provisions Exceptions Exception 1: Buildings with permanently installed on-site renewable energy systems Exception 2: Solar-ready zone shaded for more than 70% of daylight hours Exception 3: Shown in construction docs to be outside of scope 18 7

8 Appendix U: Solar-Ready Provisions Exceptions 19 Appendix U: Solar-Ready Provisions AU Construction Documentation Solar panel layout or solar-ready zone indicated on plans Solar panel layout 20 8

9 Appendix U: Solar-Ready Provisions AU Solar-ready zone area The solar-ready zone shall not be less than 300 sqft. Or If the house is A townhouse three stories or less, and Total floor area less than 2000 sq.ft The solar ready zone shall not be less than 150 sqft. These areas are exclusive of mandatory access or set-back areas as required by 527 CMR (fire safety code) 21 Appendix U: Solar-Ready Provisions AU Solar-ready zone area The solar-ready zone areas shall be composed of: Areas not less than 80 square feet At least 5 ft. wide 80 sq.ft. area 22 9

10 Appendix U: Solar-Ready Provisions AU Obstructions The solar-ready zone should not be obstructed, including but not limited to: Vents Chimneys Roof-mounted Nothing in Appendix U shall require the construction documents to be redesigned/reconfigured for solar-ready zone 23 Appendix U: Solar-Ready Provisions AU Roof Load Documentation The structural design loads for live and dead loads should be clearly indicated on construction documentation 24 Image Source: 10

11 Appendix U: Solar-Ready Provisions AU Interconnection Pathway Construction drawings should indicate: Pathway for electrical conduit from the solar-ready zone to the electrical panel (PV) Or Plumbing pathway from the solar-ready zone to the service hot water system (solar thermal) 25 Appendix U: Solar-Ready Provisions AU Electrical Service Reserved Space The main electrical service panel shall have a reserved space to allow installation of a dual pole circuit breaker for future solar installation It shall be labeled For Future Solar Electric Space for Dual pole circuit breaker to be located at the opposite end and labeled Input Feeder/Main 26 Reference: 11

12 Appendix U: Solar-Ready Provisions AU Construction Documentation Certificate A permanent certificate, indicating solar-ready zone and other requirements of this section shall be posted at a conspicuous location (electrical distribution panel, water heater, etc.) by the builder/registered design professional 27 Duct insulation, Duct leakage, Piping insulation, Mechanical Ventilation, ERI Path SIGNIFICANT CHANGES BETWEEN 2012 IECC AND 2015 IECC 29 12

13 1. Duct Insulation R IECC Location of ducts R-value of duct insulation Supply ducts in attics R 8 All other ducts elsewhere R IECC Location of ducts Supply and Returnducts in attic Supply and Return ducts elsewhere R-value of duct insulation R-8 when 3 inch diameter R-6 when 3 inch diameter R-6 when 3 inch diameter R-4.2 when 3 inch diameter No duct insulation required in conditioned space. 30 R Duct Insulation High-velocity ducts 31 Source: 13

14 2. Duct Leakage Prescriptive leakage rates are unchanged New distinction between Mandatory vs. Prescriptive Leakage testing is mandatoryregardless of compliance path Leakage limits(below) only apply to prescriptive path Location of ducts Rough-in test total duct leakage 2012 IECC & 2015 IECC R-value of duct insulation 4 cfm/100 sf when air handler installed 3 cfm/100 sf when air handler not installed Postconstruction test Total leakage less than or equal to 4 cfm/100 sf N : Testing and verification of ducts to be done by HERS Rater, HERS Field Inspector or BPI Certified Professional Pipe Insulation R Hot water pipe insulation (Prescriptive) IECC 2012 R-3 required for hot water piping larger than ¾ inch nominal diameter R-3 for piping from water heater to kitchen outlets IECC 2015 R-3 required for hot water piping ¾ inch nominal diameter and larger R-3 for piping from water heater to kitchen outlets Decreases energy efficiency Increases energy efficiency ¾ inch is the most common size for long trunk lines in typical residences, this change is likely to improve efficiency as a whole. 33 Reference: 14

15 4. Mechanical Ventilation Why Ventilate? Indoor Air Quality Fresh air Diluting pollutants (Carbon monoxide, radon, off-gasing from building materials, burnt oil is carcinogenic etc.) Moisture control Have to rely on the occupants opening windows Inadequate air flow without mechanical ventilation 34 Why Ventilate? Source:

16 Build Tight and Ventilate Right Leaky homes transfer more (or less) air than required. Is the air really fresh? Results in condensation in envelope assemblies which causes mold growth Mechanical ventilation gives you control over quality as well as quantity of air flow. 36 Problems with depending on only Natural Ventilation? Natural ventilation depends on temperature and humidity differences between inside and outdoors Large variation in the amount of ventilation throughout the day/season/year

17 Why Ventilate? (Very leaky) (Leaky) (Tight) Source: ASHRAE 62.2 and Ventilation Philosophy, Energy Trust of Oregon 38 Local Exhaust vs Whole House Exhaust The purpose of local exhaust is to remove pollutants at their point of origin. Whole-house ventilation provides fresh air for people and dilutes pollutants emitted from building materials IRC Section M deals with Local Exhausts Local exhausts rates are different from the required mechanical ventilation rates -which can be served by whole house exhaust. Ventilation rates are determined separately. Local Exhausts, when operated continuously, can serve towards mechanical ventilation requirement

18 Mechanical Ventilation MA Amendment Formula Stack Effect 40 Mechanical Ventilation MA Amendment Formula Wind Effect 41 18

19 Code Section and Language R403.6 Mechanical Ventilation (Replaced by MA Code Amendment Mandatory N1103.6) Each dwelling unit of a residential building shall be provided with continuously operating exhaust, supply or balanced ventilation that meets the requirements of: Energy Star Homes Version 3.1 ASHRAE ; or Per formula the following formula ASHRAE 62.2 Formula MA Amendment Mechanical Ventilation MA Amendment Formula S Building Height Factor Stories above grade S WSF Weather Shielding Factor County Barnstable 0.60 Berkshire 0.52 Bristol 0.54 Dukes 0.59 Essex 0.58 Franklin 0.52 WSF 19

20 ASHRAE 62.2 Calculator Source: 44 Mechanical Ventilation ENERGY STAR HOMES Version 3.1 Ventilation air flow rate and run-time meet the requirements of ASHRAE or later The system shall have at least one supply or exhaust fan with associated ducts and controls. Local exhaust systems are allowed to be part of wholehouse mechanical ventilation 20

21 N Mechanical Testing and Verification Installed performance of the mechanical ventilation system shall be tested and verified by HERS Rater HERS Rating Field inspector BPI Certified Professional And measured using a flow hood, flow grid or other air measuring device in accordance with either RESNET Standard Chapter 8 or ACCA Standard N Mechanical Testing and Verification Source:

22 N Mechanical Testing and Verification Residential Checklist 48 Local Exhaust and Whole House Ventilation Strategies Source: 22

23 Types of Ventilation Strategies Exhaust-Only Ventilation Supply-Only Ventilation Balanced Ventilation Balanced flow with supply and exhaust working at the same air flow rate Energy Recovery Ventilation Heat Recovery Ventilation Mechanical Ventilation Exhaust-Only Ventilation Types of exhaust ventilation systems Single-point Multi-point from bathrooms Multi-point from bedrooms/common areas Source:

24 Mechanical Ventilation Single-Point Exhaust Ventilation 52 Source: Mechanical Ventilation Multi-point Exhaust Ventilation 53 Source: 24

25 Mechanical Ventilation Multi-point Exhaust Ventilation Source: 54 Mechanical Ventilation Pressures in the house due to Exhaust-Only Ventilation Source:

26 Mechanical Ventilation Advantages/Disadvantages of Exhaust-Only Ventilation Advantages Simple to install and inexpensive Removes pollutants at the source Can be used as a part of whole-house ventilation The negative house pressure lowers condensation risk Disadvantages Source of air unknown Backdraft of combustion air Other pollutants, such as radon, may enter the house Air not distributed evenly throughout the house 56 Mechanical Ventilation Bad Installation Practices 57 26

27 Mechanical Ventilation Bad Installation Practices Manufacturer instructions tell you the total length and equivalent length for bends in ducts. Mechanical ventilation testing helps in making sure installation is proper Source: Mechanical Ventilation Bad Installation Practices 59 Source: 27

28 Mechanical Ventilation Supply-Only Ventilation 60 Source: Mechanical Ventilation Supply-Only Ventilation Source:

29 Mechanical Ventilation Pressures in the house due to Supply-Only Ventilation Source: 62 Mechanical Ventilation Advantages/Disadvantages of Supply-only Ventilation Advantages Inexpensive; can use existing duct systems Better distribution of fresh air Air being distributed can be filtered Positive pressure means pollutants can be stopped from infiltrating into the house Disadvantages Uncomfortable drafts of air at the point of intake Warm moist air is forced through cracks and holes in wall and ceiling assemblies Using air-handler fan results in higher electricity use Air-handler limitations on the temperature of intake air 63 29

30 Mechanical Ventilation Balanced Ventilation with supply and exhaust 64 Source: Mechanical Ventilation Balanced Ventilation with HRV/ERV 65 Source: 30

31 Mechanical Ventilation Balanced Ventilation with HRV/ERV Source: 66 Mechanical Ventilation What is an ERV? Cold outside air Exhaust air/conditioned air ERV can have recovery efficiencies of over 70%. Heat exchanger 67 31

32 Mechanical Ventilation Difference between ERV and HRV ERV and HRV are very similar ERV transfers both heat and moisture HRV transfers only heat 68 Mechanical Ventilation R Fan Efficacy Requirements In-line fan minimum efficacy is 2.8 cfm/watt For a house that requires 65 cfm (earlier example), Fan Wattage required is 65 cfm / 2.8 = 24 Watt Depending on the house, wattage may vary

33 Mechanical Ventilation Advantages/Disadvantages of Balanced ventilation Advantages Can recover energy in some cases (ERV/HRV) Applicable in all climate zones Source of ventilation air known Filtered and tempered outdoor air House pressure approximately equal to outside Disadvantages Expensive Requires proper planning during the design phase Local exhaust still required if not exhausting from bathrooms ERI Path/HERS Index Section R401.2 Compliance (Amended) Compliance Paths Prescriptive with MA Amendments Sections N through N1104 Simulated Performance Alternative with Mandatory Provision Sections N1105 & Mandatory provisions Energy Rating Index or Alternate Compliance Paths Sections N

34 Section R401.2 Compliance (Amended) ERI and Alternative Energy Performance Rating Paths Certified RESNET HERS Rating with MA Amendments Certified Energy Star Homes Version 3.1 Certified Passivehaus Performance method 74 Maximum HERS Index Score Table R (N ): Max. HERS index with onsite renewable energy systems Renewable Energy Source New Construction Maximum HERS Index Whole House Renovations; Additions None Renewable System: Solar PV > 2.5 kw, or Renewable primary heating system 2 Renewable Systems: Solar PV + Solar thermal DHW, or Renewable primary heating + solar thermal DHW 3 Renewable Systems: Solar PV + Renewable primary heating + solar thermal DHW Section N1106.4: The building should have a HERS score less than the score listed in the table prior to credit for onsite renewable electric generation

35 Energy Performance Index/HERS Index Table R (N ): Maximum HERS index scores with onsite renewable energy systems Renewable Energy Source New Construction Maximum HERS Index Whole House Renovations; Additions None HERS score should not exceed 55 for New Construction Section N :Post-construction or rough-in testing and verification shall be done by HERS Rater HERS Rating Field Inspector BPI Certified Professional 76 Energy Performance Index/HERS Index Renewable Primary Heating: 1. Clean Biomass heating System 2. Solar thermal array 3. Ground Source Heat Pump 4. Or a combination of all the above These systems offset 5 HERS points Wood-pellet fired central boilers with a thermal efficiency of at least 80% 77 Reference: 35

36 Energy Performance Index/HERS Index Two points are offset for Solar thermal array for DHW Clean Biomass Stove Wood or pellet-fired stoves that are EPA certified Reference: Energy Performance Index/HERS Index Solar Photovoltaic 2.5 kw Clean Biomass Heating system Ground Source heat Pumps Solar thermal array for Domestic Water Heating Clean Biomass Stove Each can offset 5 HERS points Each can offset 2 HERS points Exception: Clean Biomass stove offset cannot be combined with primary heating system offset

37 Appendix AA Stretch Energy Code 9TH EDITION STRETCH CODE 80 9th Edition Stretch Code New Construction Simplified for 9 th Edition 8 th Edition Stretch Code requirements New Stretch Code for New Construction for New Construction (3 stories or less) (4 stories or less) -until Dec 31 st, from Jan 1, 2017 Dwelling unit size (CFA) Maximum HERS score Units 3000 sq.ft. 65 Maximum HERS Score of 55 for New Construction (can be higher if renewables are installed) Passive House Institute US (PHIUS) Approved Software Units < 3000 sq.ft. 70 ENERGY STAR Homes 3.1 Path Should also comply with Energy Star Thermal Bypass Inspection Checklist Should also comply with Mandatory Air leakage requirements of IECC 2015 and Table R The 9 th Edition Stretch Code includes 4 story residential buildings

38 9th Edition Stretch Code Existing Buildings For alterations, renovations, additions and repairs of existing buildings, Stretch Code refers back to MA Residential Energy Code (780 CMR 51.00). 82 Summary Solar-ready provisions are applicable to new construction, except additions. Solar-ready zone, roof load documentation, pathway for conduit should be shown on construction drawings. Duct testing is a mandatory requirement. Mechanical ventilation is mandatory can be supply only, return only or balanced. New ERI Path requires HERS 55/ENERGYSTAR v3.1 or Passive House. Renewables should not be modeled in the HERS report. Stretch Code requires one of the above compliance paths. No special requirements for existing buildings in Stretch Code

39 Energy Code Support Questions about the energy code? Energy Code Support Hotline: Energy Code Support 84 Residential New Construction Incentives for energy efficient building and renovating Low-Rise New Construction Performance Path based upon Electric and Fuel savings, plus a % adder as compared to MA baseline incentives up to $10,000 High-Rise New Construction and all Master Metered Natural Gas Incentives based upon modeling by Program Manager Incentives also offered for existing buildings. Visit for the details

40 Residential New Construction Incentives Blended Savings Approach (BSA) Details at: 86 Thanks! Massachusetts Energy Code Technical Support Program 87 40