Multifamily Energy Efficiency Web Training 80 Slides. Intent of Web Training. Provide an overview of energy efficient and cost-effective design strategies for multifamily new construction buildings Benefits of energy efficiency in multifamily new construction buildings
Intent of Web Training • Provide an overview of energy efficient and cost-effective design strategies for multifamily new construction buildings • Benefits of energy efficiency in multifamily new construction buildings • Building energy code applicable to low-rise and high-rise buildings • Energy efficiency design concepts • Information on financial incentives, and • List of resources for energy efficiency It should take approximately one hour to review the contents of this training. This is not a comprehensive training, but will provide you with links to additional resources where you can learn more about multifamily energy efficiency.
Overview of Content • Introduction: The Value of Energy Efficiency in Multifamily Buildings • Unique Aspects of Multifamily Building Construction • Design Concepts and Practices for Energy Efficiency in Multifamily Buildings • Energy Efficiency Measure Selection • Envelope • Heating • Cooling • Water Heating • Lighting • Appliances
Overview of Content How to Achieve at Least 15% Better than Code Using an Integrated Approach How to do Cost-Benefit and Payback Analyses Case Study Non-Energy Benefits of Energy Efficiency Financing for Energy Efficiency and Green Measures Summary Resources
Introduction Value of Energy Efficiency in Multifamily Buildings
Why Energy Efficiency? Energy efficiency saves money, energy, and resources… making homes more affordable, comfortable, and attractive to residents. It increases: • Comfort • Energy Savings • Property Value • Maintenance Savings • Tenant Payment Security …to list a few A minimally compliant Title 24 building is the worst building you can legally build in California!
CA Residential New Construction Multifamily is making its way back into new construction • Overall home-building is down, but the proportion of multifamily to single family units permitted in California is growing* • 45% of new California homes permitted between January and September 2008 were multifamily* * U.S. Census Bureau
Multifamily Trends and Projections The California Department of Finance projects there will be over 44 million people in 2020 (almost 5 million more than California’s current population) More people equates to more demand for housing
Unique Aspects of MF Buildings • MF buildings come in high-rise and low-rise varieties • Building design, equipment selection, construction practices, and code regulations vary by building type • MF buildings often include nonresidential areas • Common spaces: Corridors, entry ways, laundry facilities, leasing offices, recreational rooms, etc. • Energy measures must be analyzed separately if more then 20% of the total floor area is common space (i.e. one energy model for the residential area, another for the non-residential are) • Mixed Use Projects • Also follow the above 20% rule if more than 20% nonresidential floor area. • Live Work Projects • Typically heated and/or cooled like a residence and using domestic water heating systems, so abide to residential standards • Lighting in designated workspaces, however, must comply with the nonresidential prescriptive lighting requirements. • MF High Rise – 4+ stories • Residential DHW and lighting code requirements • Non residential HVAC and envelope measures • MF Low Rise - 3 or fewer stories • All residential code requirements
Unique Aspects of MF Buildings • Split Incentives • Developers have less financial incentive to invest in energy efficiency when they don’t benefit from utility bill savings • Energy efficiency measures typically benefit the tenants • Depending on whether the energy using systems are centralized or individually metered… the cost of the energy use is borne by the space occupants or the building owner/management. • Energy use schedules vary • It’s difficult to predict when many tenants will be occupying the building. • Domestic Hot Water (DHW): The energy used to heat water is typically a higher percentage of the overall energy due to increased occupant density and reduced building envelope areas.
Cost Benefits of Energy Efficiency You’re probably asking yourself: Does energy efficiency really add value to a building? As energy costs continue to sharply rise, where will people want to live? Owners: can you afford not to build an energy efficient building? Designers: can you afford not to design energy efficient buildings?
First cost is important to consider, but the life-cycle cost is an even more valuable metric …
Cost Benefits of Energy Efficiency So … what are the costs of energy efficiency? • Incremental first costs • Risk (design or installation errors) • Delays (procurement or design) • Maintenance (knowledge) • Financing
Offsetting Additional Costs What’s out there to help offset those costs? • City & Local Support • State and Federal Tax Credits Increased Basis Threshold • Residential Utility Incentive Programs • New Construction • Policy programs • Energy Efficiency-Based Utility Allowance (EEBUA) schedules • Green Building Programs • LEED New Homes • BIG Green Points • Enterprise Green Communities • NAHB Green Builder • Smart Design • Lead to potential lower number of call backs • Lower construction costs
Design Concepts and Practices for Energy Efficiency in Multifamily Buildings
Design Team Early team collaboration results in the most cost-effective solutions: • Involve an energy consultant as early as possible in the design process • Optimize building orientation, window areas and any other potential design restrictions BEFORE they are locked in by the entitlement process • Title 24 can be started in schematic drawing phase E Consultant Engineers Architect Owner/Dev Financing Builder Goals/Objectives Maximize Efficiency Minimize Cost Design & Program Parameters/Options Energy Efficiency Design Options Marketing Strategies Financing Options Building Strategies Analysis Energy Simulation Alternatives Cost Analysis Non-energy benefits Final Decisions Obtain Permits Construction Documents Secure Funds Inform all contractors
Title 24 Basics • Mandatory Measures • Lighting efficiency • Shell insulation minimums • Equipment efficiency minimums • Appliance standards • Prescriptive Packages offer a checklist of compliance measures • Establishes Performance baseline • Climate Zone dependant • Performance Calculation allows trade-offs to meet the standard energy budget (baseline) • Envelope: • Orientation, Insulation, Windows, Assemblies • HVAC: • Heating and Cooling equipment and distribution • DHW: • Central and individual water heating equipment & distribution
Title 24 Basics • 2005 code was 24.3% more stringent than 2001 for electricity use and 15.7% for gas usage for new multifamily buildings* • 2008 code is 19.7% more stringent than 2005 for electricity use and 7% for gas usage for new multifamily buildings* • Lower prescriptive U-factors for windows • Additional HERS measures • Required ventilation in residential code • Minimum prescriptive reflectivity of roof materials in specific CZ • Opaque building elements have different default assumptions in non-res calculation methods • Improved controls required for outdoor lighting * California Energy Commission’s Energy Impact Analysis for 2005 and 2008 Title 24, respectively.
Flat Energy Value used in prior standards Time Dependent Energy Value in 2008 Standards are ‘Peakier’ than the 2005 Standards TDV Values - 2008 Standards TDV Values - 2005 Standards With TDV value a kWh saved during a high-cost peak hour is valued more highly than a kWh saved during an off-peak hour Energy value With flat energy value a kWh saved is valued the same for every hour of the day Time of Day Time Dependent Valuation (TDV) • TDV affects energy trade-offs in the performance approach by changing the way energy is ‘valued’ based on the time of use of that energy • Before 2005, T24 energy use estimates had a constant value regardless of the time of use • TDV assigns higher value for on-peak savings, lower value for off-peak savings
Time Dependent Valuation (TDV) • TDV favors technologies that save more energy on-peak than off-peak (and dings harder for wasteful peak usage) • Greater credit for: • Higher EER air conditioners • Lower SHGC glazing • Better duct insulation (in unconditioned spaces) • Daylighting controls for lighting • Greater penalties for: • West-facing glass • Oversized, unshaded windows/skylights • Generally neutral for: • Economizers • Envelope insulation • High efficiency water heating • This affects trade-off choices using the performance approach (computer simulation)
Third PartyVerification Building department focus is Health and Life Safety, not energy efficiency Energy savings are not realized unless measures are installed properly HERS rater verifies measures for T-24 compliance Provide quality assurance, making certain that products are installed properly for maximum safety and efficiency Three C-HERS providers: CHEERS, CalCERTS, CBPCA Commissioning Does not give credit in T-24 performance or prescriptive, but a worthwhile option for you to consider Assures that equipment is working as designed 21
Third PartyVerification • The following measures require HERS verification if claimed for minimal Title 24 code compliance (or ENERGY STAR compliance): • New in 2008 code • Low Leakage Air Handlers • Refrigerant Charge Indicator Light Display • Verified Cooling Coil Airflow • Evaporatively Cooled Condensers • Ice Storage Air Conditioners • QII for Spray Polyurethane Foam • PV Field Verification Protocol • Continued from past years • Reduced Duct Leakage (6%) • Supply Duct Location • Deeply Buried Ducts • Duct Surface Area and R-value • Air Handler Fan Watt Draw • Refrigerant Charge • High EER for A/C • Maximum Cooling Capacity • Building Envelope Sealing • Quality Insulation Installation (QII)
Energy Efficiency Measures • Apply your understanding of individual measures to an integrated design approach • The goal is to have a good ‘package’ of measures that are cost-effective in the long run and minimize first costs as much as possible • Site Considerations • Building Envelope Options • HVAC Equipment • Water Heating System • Lighting • Appliances • Operations & Maintenance • Climate • Solar Access • Orientation These are used in Title 24 performance compliance calculations • Insulation • Radiant barrier • Cool roof • Attic venting • Windows and glazing • Shading of building and windows (vegetation, overhangs, etc) • Infiltration/leakage • Quality insulation • Space heating and cooling • Correct sizing and distribution • Central or individual • Storage or tankless • Distribution controls • Location • Pipe and tank insulation • Hardwired high efficacy lighting fixtures (CFLs, LEDs, etc) • Lighting controls (dimmers, occupancy sensors, photometric sensors) ENERGY STAR® dishwashers, refrigerators, clothes washers and natural gas clothes dryers Leave a guide on how to maintain and operate a high performance building
California’s Climate Zones • There are 16 in California • The best package of measures will vary by building design and climate zone • Each building is unique, so there is no single “silver bullet” solution for every buildings Coastal Climate Zones: 1-7 Inland Climate Zones: 8-16
Envelope: Site Considerations • With careful design, the building envelope can control loads that affect residential building heating and cooling energy use • Keep out summer heat • Allow heat penetration from the sun in the winter • Buildings interact with site influences such as sun and wind through • Shape and shade • Building Orientation • Inter-building shading to minimize afternoon solar heat gain • Plant deciduous trees on the south side • Material properties • Solar transmittance of windows • Air infiltration properties of building envelope • Reflectivity and emissivity of outer surfaces • Short faces of building East-West reduce heat gain when the sun is at low angles in mornings and afternoons • Long faces of building facing North-South allow heat gain when the winter sun is lower in the sky • Shade with summer leaves and allow sun penetration when bare in winter
Envelope: Windows and Ventilation • Ventilation • Cross Ventilation • Inlet without outlet - Breeze will not really enter space • Inlet and outlet - Cross ventilation occurs. Stack effect improves flow • Stack Effect: Window or roof opening for the outlet in a higher position than the opening for the inlet • Warm air rises and exhausts • Resulting low pressure draws air in through lower openings • Windows • Use appropriate shading devices • Minimize SHGC and U-factors • Select based on NFRC* performance values • Dual glazing – also provides acoustic insulation • Better windows can result in reduction of heating and cooling equipment size – saving first costs * NFRC = National Fenestration Ratings Council * SHGC = Solar Heat Gain Coefficient
Envelope: Windows and Ventilation What do window ratings mean? • SHGC: Fraction of solar radiation thru window (Solar Heat Gain Coefficient) • If SHGC=0.53, 53% of solar heat gain transmitted • Look for SHGC of 0.35, or less • VLT: Amount of visible light transmitted • If VLT=0.75, 75% of visible light transmitted • Look for VLT of 0.50 or more • U-factor: Rate of heat loss: • Low-emittance (Low-E) coatings are deposited on a window to suppress radiative heat flow (reduce U-factor) • Look for U-factor of 0.40 or less • Air Leakage: Rate of Infiltration
Envelope: Insulation Basics • Insulation resists the flow of heat • Measured by R-value (R = Resistance) • Types: • Fibrous Insulation: Blankets, Batts, Loose-fill • Spray Foam • Rigid Foam Panels • Insulated Concrete Forms (ICF) • Structural Insulated Panels (SIPS) • Better insulation can help reduce HVAC equipment size by reducing heating and cooling loads Source: www.buildingscience.com Source: www.southface.org Source: www.california-siphomes.com Source: www.penta.ca Source: www.wdcicf.com Source: www.mybungalow.com
Envelope: Insulation Basics • Insulation is cost effective when installed correctly: • In continuous contact with air barrier • No gaps • No compressions • No voids • Standard Practice: Poor installation • Gaps and voids • Not in contact with air barrier (drywall) • Compression
Envelope: Insulation Basics Due to poor installation practices: • Insulation R-value is devalued by 13% when using the performance approach for T-24 compliance, unless… • A quality insulation installation (QII) inspection is conducted by a HERS rater and passes the following points: • Fully lofted and filled framing cavities (no compression) • Full contact with air barrier • Rim joists insulated • Batts butt-fit or split around wiring and plumbing • Wall cavities caulked or foamed for air-tight seal • Pre-insulation of hard-to-access wall stud cavities • Knee walls and skylight shafts insulated to min. R-19 • Insulation over all recessed lighting fixtures
Envelope: Insulation Basics Due to poor installation practices: • Insulation R-value is devalued by 13% when using the performance approach for T-24 compliance, unless… • The Thermal Bypass Checklist and QII are requirements for the ENERGY STAR for Homes label • The checklist requires inspection of the following to ensure the building envelope is thermally efficient: • Overall air barrier and thermal barrier alignment • Walls Adjoining Exterior Walls or Unconditioned Spaces • Floors between Conditioned and Exterior Spaces • Shafts • Attic/Ceiling Interface • Common Walls Between Dwelling Units
Envelope: Radiant Barrier Radiant barrier is most effective in cooling-dominated zones because it reflects heat from the sun, preventing it from penetrating the attic space • Benefits • Can reduce attic heat by up to 30% and block up to 97% of radiant heat gain • Reduced heat gain in duct work • Does not carry heating penalty of cool roofs • No additional labor costs (new construction) • Types • Single-sided foil stapled to roof joists (retrofit) • Foil-faced roof sheathing (new construction) • Installation • Must be adjacent to air gap • Must face down (to avoid dust accumulation)
Heating and Cooling Federal Appliance Standards • SEER 13 Federal Standards in effect since Jan 23, 2006 (National Appliance Efficiency Conservation Act) • Title 24 does not govern equipment efficiency of federally mandated equipment
HVAC Equipment Sizing Properly sized equipment can reduce energy usage by as much as 35% • Energy loss due to improper sizing can be greater than savings from higher efficiency equipment • Tools for proper sizing • The Air Conditioning Contractors of America (ACCA): www.acca.org • Guidelines for sizing HVAC equipment & ACCA Manual J Residential Load Calculation • The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE ): www.ashrae.org • Handbooks • Sheet Metal and Air Conditioning Contractors' National Association (SMACNA): www.smacna.org • Residential Comfort Manual
Tools for HVAC Selection • Directory of ARI (Air Conditioning & Refrigeration Institute) Verified HVAC Equipment www.ceehvacdirectory.org • California Energy Commission Certified Equipment Directory www.energy.ca.gov/appliances/appliance • ENERGY STAR® Savings Calculator www.energystar.gov/ia/business/bulk_purchasing/bpsavings_calc/Calc_CAC.xls
SEER vs. EER Minimum air conditioner efficiency is based on SEER (Seasonal Energy Efficiency Ratio) because of Federal Standards SEER is the only performance indicator allowed on manufacturer labels SEER test conducted at 82º F: Southeast US; warm, humid climates EER (Energy Efficiency Ratio) is the full load efficiency at specific operating conditions EER test conducted at 95º F: California conditions; hot, dry climate Helps reduce peak loads Credit granted for higher EER in 2008 Title 24 Manufacturers not required to report EER Requires HERS inspection to obtain Title 24 credit
HVAC: HERS Compliance Measures • High Efficiency Air Conditioner • Air Handler Watt Draw • Minimum Cooling Capacity • Duct Sealing and Testing • Low Leakage Air Handlers • Refrigerant Charge Measurement or Refrigerant Charge Indicator Light Display • Duct Location (within conditioned space) • Blower Door Test (Envelope infiltration) • Verified Cooling Coil Airflow • Evaporatively Cooled Condensers • Ice Storage Air Conditioners • Higher SEER • Higher EER • High efficiency fan & duct system with low wattage fan • “Right sized” cooling system criteria Source: National Renewable Energy Laboratory • Reduce duct leakage to 6% • No more than 12 lineal feet of supply duct is outside the conditioned space • 12’ includes the air handler and plenum length
Ducts Reduce distribution losses by: • Placing ducts within conditioned space • Conduct tight duct test • Increase duct insulation • Correctly size ducts • Run duct as straight as possible • Unsealed duct systems can leak 20-40% of their conditioned air • Tight ducts are <6% R-4.2, 6 or 8 duct insulation prescriptively required depending on climate zone An exception is allowed if more efficient windows and/or HVAC systems are provided (except CZ 15)
Water Heating Types Water heating energy represents a significant portion of the overall energy budget in multifamily buildings • Water Heating System Considerations: • Storage or Tankless/Instantaneous • Gas or Electric • Central or Individual • Indirect or Direct • Integrated with space heating system?
Water Heating: Central Systems Important Elements of Energy Efficient Central Water Heating Systems • High efficiency hot water source • Recirculation loop designed for efficiency • Recirculation loop controls • Well insulated hot water piping and storage tank • Efficient fixtures and appliances that reduce hot water consumption • Large boilers with indirect storage tanks last longer than smaller water heaters and can often be repaired rather than replaced. • The federal minimum standard for large gas boilers is 80% thermal efficiency • Simple atmospheric boilers can reach a maximum of about 82% thermal efficiency • Condensing boilers can attain thermal efficiencies up to 98% by capturing the sensible and latent heat from the flue gases. • Central hot water systems designed with continuous recirculation systems are simple and keep tenant complaints to a minimum, but are extremely inefficient. • Significant energy savings can be achieved with a well designed “structured plumbing” recirculation loop and advanced boiler modulation and/or demand controls • Timer Controls shut off the recirculation pump at time when the hot water draw is expected to be minimal • Temperature Controls shut off the recirculation pump when the return water reaches a temperature threshold • Demand Controls are more advanced than the basic timer and temperature controls, charging the loop with hot water in response to demand • Temperature Modulation Controls save energy by reducing the temperature of the tank water in times of low demand
Water Heating: Central Systems Trade-Offs of Central DHW systems • Hot Water Sub-Metering • Conservation vs. Efficiency • Tenants have incentive to conserve water and energy when they pay the utility bill • Utility Submeter Applications manufactures only CA approved hot water sub-meter • Boiler Performance & Maintenance • Condensing or not, boilers require annual tune-ups • Specialty service and corrosion resistant parts cause higher maintenance costs • Efficiency varies with operating condition temperatures
Water Heating: Solar Hot Water • Title 24 does give credit for solar hot water heating (solar PV does not) • Solar hot water is one of the easiest methods of achieving high levels of energy efficiency • Alternative to high-efficiency boilers • Particularly complimentary to central systems • T-24 consultant uses a savings fraction calculator, and solar designer determines size of the actual system • Solar fraction = the percentage of total hot water heating that the solar system will deliver Image Sources: www.findouthow.co.uk www.solaroptions.biz
Lighting Lighting Terminology • Lamp = Light Bulb • Lumen = A unit of Visible Light • Luminaire = Light Fixture • Efficacy = Efficiency of Lighting Product (Lumens/watt)
Tri-Phosphor Fluorescent Same technology as color television There is only one “full spectrum” lamp Compact Fluorescent Light Bulbs (CFL) Can be used throughout the home Availability and selection increasing LED (Light Emitting Diode) Approx 20 lumens per watt Can be installed: Under counters Hallways, staircases Still limited by production Lighting Controls Dimmers Occupancy Photosensors Timers Motion Sensors Lighting
Lighting All Title 24 lighting requirements are mandatory • Not part of prescriptive package • Not part of residential energy performance calculation budget • Primarily impacts dwelling units • The Standards apply only to permanently installed luminaires
Lighting T-24 Residential Lighting Standards • Kitchens • 50% of total wattage must be high efficicacy • Low efficicacy luminaires must be switched separately • Bathrooms, garages, laundry rooms, closets, and utility rooms • High efficacy OR Controlled by a manual-on occupant sensor • All other residential spaces • High efficacy OR Controlled by a dimmer switch or manual-on occupancy sensor
Appliances Look for the ENERGY STAR® label on all appliances • Refrigerators • Choose refrigerators 20+% more efficient than federal standards • Top freezer models are more efficient than side-by-side models • Refrigerators under 25 cubic feet are sufficient • Dishwashers • Look for models that save water AND energy • Energy Factor (EF) of at least 0.65 • “no heat dry” option can save additional energy • Clothes Washers • High Modified Energy Factor (MEF) - dryer and water heating energy • Low Water Factor (WF) - gallons needed per cubic foot of laundry • Front loading washers are generally more efficient than top loading • Clothes Dryers • Dryness sensor for automatic shut-off when clothes are dry Discount for bulk purchases at www.quantityquotes.net
How to Achieve at Least 15% Better than Code using Integrated Approach
Achieving 15% Better Than T-24 What measures are needed in 2008 standards to get a ~15% compliance margin? • Measures vary by building type • High rise versus low rise • Central versus distributed systems • Amount of building self shading • Building geometry • Measures vary by climate zone • Focus on measures affecting largest energy use • Peak demand related measures first • The “average” answer has little use. There is no “magic bullet” solution for all buildings and climate zones