Transcript Intent of web training - Energy Design Resources

1
Multifamily
Energy
Efficiency
Web Training
80 Slides
Intent of Web Training
• Provide an overview of energy efficient and costeffective 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.
2
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
3
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
4
5
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!
6
CA Residential New Construction
7
Multifamily is making its way back into new
construction
MultifamilyUnits
Construction
Residential
Permitted
as % of Total Residential Construction
60.00%
Overall home-building is down, but the
proportion of multifamily to single family
units permitted in California is growing*
Multifamily
Residential Permits
2008 Construction
as % of Total Residential Construction
60.00% Multifamily Single Family
40.00%
30.00%
20.00%
10.00%
54.76%
•
30.00%
45.24%
20.00%
2007
2005
2003
2001
1999
1997
1995
1993
1991
1989
1987
1985
0.00%
1983
Est.
2008
2007
2005
2006
2003
2001
2004
1999
1997
2002
1995
1993
1991
2000
45% of new California homes permitted
between January and September 2008
were multifamily*
10.00%
* U.S. Census Bureau
1989
1998
1987
1983
0.00%
50.00%
40.00%
Multifamily
50.00%
1985
•
Single Family
Multifamily Trends and Projections
8
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 High Rise
– 4+include
stories nonresidential areas
• MF buildings
often
– Residential
and lighting
code ways,
requirements
– Common
spaces:DHW
Corridors,
entry
laundry
– Nonleasing
residential
HVAC recreational
and envelope measures
facilities,
offices,
rooms, etc.
•• MF
Lowmeasures
Rise - 3 or
fewer
Energy
must
bestories
analyzed separately if more
– All
residential
code requirements
then
20%
of the total
floor area is common space (i.e. one
energy model for the residential area, another for the nonresidential 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.
9
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.
10
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?
11
12
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
13
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
14
15
Design Concepts and Practices
for Energy Efficiency in
Multifamily Buildings
Design Team
16
Early team collaboration results in the most
cost-effective solutions:
• Involve an energy consultant as early as possible in the design
process
Consultant
Engineers
Architect
Builder
• OptimizeEbuilding
orientation,
windowOwner/Dev
areas andFinancing
any other
Goals/Objectives
potential design restrictions BEFORE they are locked in by the
Maximize
Minimize
Design &
entitlement
process
Efficiency
Cost
Program
• Title 24 can be started in schematic drawing phase
Parameters/Options
Energy Efficiency Design Options
Marketing
Strategies
Financing
Options
Building
Strategies
Analysis
Energy
Simulation
Alternatives
Non-energy
benefits
Cost Analysis
Final Decisions
Construction
Documents
Obtain
Permits
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
17
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.
18
Time Dependent Valuation (TDV)
19
• 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
Flat Energy Value
used in
prior standards
Time Dependent Energy Value in 2008
Standards are ‘Peakier’ than the 2005
Standards
Energy value
TDV Values - 2008 Standards
TDV Values - 2005 Standards
With TDV value a kWh saved during a highcost peak hour is valued more highly than a
kWh saved during an off-peak hour
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 favors technologies that save more energy onpeak 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)
20
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 Party Verification
22
• The following measures require HERS verification
if claimed for minimal Title 24 code compliance (or
ENERGY STAR compliance):
– New in 2008 code
– Continued from past years
• 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
•
•
•
•
•
•
•
•
•
•
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)
23
Energy Efficiency
Measure Selection
Energy Efficiency Measures
24
• Apply your understanding of individual measures to an integrated
design approach
• The goal is to have a good ‘package’ of measures that are costeffective 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
These•Insulation
are used
in Title
24 performance
•Solar
Access
compliance calculations
•Space
heating
•Radiant
barrierand cooling
•Orientation
•Correct
and
•Cool roofsizing
•Central
or individual
distribution
•Attic
venting
•Storage
or tankless
•Hardwired
high efficacy
lighting
fixtures
(CFLs,
•Windows
andcontrols
glazing
•Distribution
• ENERGY
STAR®
LEDs,
etc)of building
•Shading
refrigerators,
and
•Location
• dishwashers,
Leave
a guide
on how to
•Lighting
controls
clothes
windows
washers
(vegetation,
and natural
maintain
and
operate
a high
•Pipe and
tank
insulation
(dimmers,
gas
overhangs,
clothes occupancy
dryers
etc)
performance
building
sensors,
photometric
•Infiltration/leakage
sensors)
•Quality insulation
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
25
Envelope: Site Considerations
26
• 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
– Short faces shading
of building
– Inter-building
toEast-West
minimize afternoon solar heat gain
reduce heat gain when the sun is at
– Plant
deciduous trees on the south side
low angles in mornings and
– Shade with summer leaves and allow
afternoons
– Material
properties
sun penetration when bare in winter
– Long
faces of building
facing North– Solar
transmittance
of windows
South allow heat gain when the
– Air infiltration
properties of building envelope
winter sun is lower in the sky
– Reflectivity and emissivity of outer surfaces
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
27
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
28
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.mybungalow.com
Source: www.southface.org
Source: www.penta.ca
Source: www.california-siphomes.com
Source: www.wdcicf.com
29
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
30
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
31
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
32
Envelope: Radiant Barrier
33
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
System Type
Split DX
Packaged Terminal
Air Conditioning/
Heat Pump
Cooling
Efficiency Metric
Seasonal Energy Efficiency
Ratio (SEER)/
Energy Efficiency Ratio (EER)
SEER/EER
Heating
Efficiency Metric
Heating Seasonal Performance
Factor (HSPF)/
Coefficient of Performance
(COP)
HSPF/COP
Advantages
Disadvantages
34
Hydronic
Fan Coil/
Heat Pump
Furnace
N/A
Energy Factor
(EF)
Annual Fuel
Utilization
Efficiency
(AFUE)
• Occupies little interior space
• Can cool multiple rooms/large
areas
• No ductwork
• Efficient in
individual rooms
• Can combine
with DHW
system
• Ducted or
ductless
• Need adjacent or roof space
• Occupies wall
space
• Seen on bldg
exterior
• Additional
plumbing
required
• Not packaged
with A/C
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 AirConditioning Engineers (ASHRAE ): www.ashrae.org
• Handbooks
– Sheet Metal and Air Conditioning Contractors'
National Association (SMACNA): www.smacna.org
• Residential Comfort Manual
35
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
36
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
37
HVAC: HERS Compliance Measures
•
•
•
•
•
•
•
•
•
•
•
High Efficiency Air Conditioner
Air
Handler
Watt Draw
– Higher
SEER
Higher
EER
– High
efficiency
& duct system with low wattage
Minimum
Coolingfan
Capacity
– fan
“Right
sized”
cooling
system criteria
Duct
Sealing
and
Testing
– Reduce
duct
to 6%
Low
Leakage
Airleakage
Handlers
Refrigerant Charge Measurement or
Refrigerant Charge Indicator Light Display
Duct Location (within conditioned space)
Blower
Doorthan
Test12(Envelope
– No more
lineal feet infiltration)
of supply duct
is outside
the conditioned
Verified
Cooling
Coil Airflowspace
– 12’ includesCooled
the air handler
and
Evaporatively
Condensers
plenum length
Ice Storage Air Conditioners
Source: National Renewable Energy
Laboratory
38
Ducts
39
Reduce distribution losses by:
• Placing ducts within conditioned
space
• Conduct tight duct test
• Increase
duct
– Unsealed
ductinsulation
systems can leak 2040% of their
air
• Correctly
sizeconditioned
ducts
– Tight ducts are <6%
• Run duct as straight as possible
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?
40
Water Heating: Central Systems
Important Elements of Energy Efficient Central
Water Heating Systems
•
•
•
•
•
High efficiency hot water source
– Large boilersloop
withdesigned
indirect storage
tanks last longer than smaller
Recirculation
for efficiency
heaters
andcontrols
can often
be repaired
than replaced.
– water
Central
hot loop
water
systems
designed
withrather
continuous
Recirculation
systems
are
simple
and
keep
tenant
–– recirculation
The
federal
minimum
standard
for
large
gas
boilers
is 80%
Well
insulated
hot
water
piping
and
storage
tank
Timer
Controls
shut
off
the
recirculation
pump
atcomplaints
time
whento
a
minimum,
but
areisextremely
thermal
efficiency
the
hotfixtures
water
draw
expected inefficient.
tothat
be minimal
Efficient
and
appliances
reduce
hot water
• Significant
energy
savings
can
be
achieved
with a well
designed
Simple atmospheric boilers can reach a maximum
of about
82%
–
Temperature
Controls
shut
off
the
recirculation
pump
when
consumption
“structured
plumbing” recirculation loop and advanced boiler
thermal efficiency
the modulation
return water reaches
a temperature
threshold
controls
• Condensing and/or
boilers demand
can attain
thermal efficiencies up to 98% by
– Demand
Controls
are more
advanced
thanthe
the
basic
timer and
capturing
the sensible
and latent
heat from
flue
gases.
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
41
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
42
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
43
Lighting
44
Lighting Terminology
• Lamp = Light Bulb
• Lumen = A unit of Visible Light
• Luminaire = Light Fixture
• Efficacy = Efficiency of
Lighting Product
(Lumens/watt)
Lighting
• 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
45
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
46
Lighting
47
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
TABLE 150-C High Efficacy Luminaire Requirements
Lamp Power Rating
Minimum Lamp Efficacy
5 watts or less
30 lumens per watt
over 5 and to 15 watts
40 lumens per watt
over 15 watts to 40 watts
50 lumens per watt
over 40 watts
60 lumens per watt
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
48
49
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
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Achieving 15% Better Than T-24
• Building simulation software can evaluate the
effectiveness of multiple measures and compare
those results with alternate combinations
– Adding insulation will reduce cooling and heating loads
– Combining a radiant barrier with a lower level of
insulation may reduce cooling loads more affectively than
maximizing insulation alone
• The goal of the integrated design process is to seek
the most cost-effective combination of energy
efficient measures
– Balance first costs and energy savings
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Achieving 15% Better Than T-24
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• The same measure or combination of measures
can result in widely divergent energy savings for
different buildings
Effects of Measure Combinations on Energy Savings
% lower energy use than code allowable
30%
Option 1 = High Eff Windows
Option 2 = High Eff Windows + Tight Ducts
Option 3 = Tight Ducts Only
Option 4 = DHW Temperature Controls
25%
20%
15%
10%
5%
0%
Bldg A
Bldg B
Bldg C
Bldg D
Achieving 15% Better Than T-24
• The same measure or combination of measures
can result in widely divergent energy savings for
different buildings
• Some measure will have more impact inland than
coastal
– Window SHGC
– Cooling EER
• Some measures will have more impact in coastal
climate zones
– DHW System Efficiency
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How to do Cost-Benefit
& Payback Analysis
Cost Benefit Analysis Process
Identify cost-effective energy
efficiency measures
Find utility rates and multiply by kWh
and Therm savings
Specify EE measures in building
energy simulation software
Find incremental cost estimate for
each measure (DEER database)*
Use simulation software output for
kWH and Therm savings
Divide estimated annual utility savings
by incremental measure costs to get
the number of year payback
If the cost-benefit numbers aren’t
satisfactory, change the mix of
measures and begin again
* http://www.energy.ca.gov/deer/
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Example: Upgrade Detail
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Original
Specification
Energy Efficiency
Upgrade
Cost
Implication
R-38
R-30 + Radiant
Barrier
$7,000
Wood frame,
2x4, R-13
Wood frame,
2x4, R-13
N/A
Dual pane,
Alum. frame
Low-e2,
Vinyl frame
$3,900
Space
Heating
Room heat
pump
(6.6 HSPF)
Room heat pump
(downsized)
(2.841 COP)
($1,163)
Space
Cooling
Room heat
pump
(10 EER)
Room heat pump
(downsized)
(11.26 EER)
Included
Water
Heating
Central Boiler,
recirc. Loop
w/aquastat control
Central Boiler,
recirc. loop
w/demand
pump control
Ceiling
Attic
Wall
Fenestration
Savings
per year
Payback
Period
$151/
Unit
1.6 years
Or
$6,070
$0.00
Note: Costs are illustrative and not definitive.
Example is also illustrative; combination of measures will vary by building and location.
$2,160
(after
$6,000
utility
incentive)
immediate
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Case Study
Case Study – Project Details
• Project name:
Cottonwood Creek Apartments
• Owner:
BRIDGE Housing Corporation
• Architect:
KTGY Group
• Location:
Suisun City, California
• California Climate Zone: 12
• Dwelling Units: 94
• Percent better than 2005 California
Residential Building Code: 17.6%
Cottonwood Creek Apartments received design assistance, cash
incentives, and training opportunities through their
participation in the CMFNH program, funded by Pacific Gas
& Electric.
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Case Study – EE Measures Installed
Overall site layout increased energy efficiency by:
• Maximizing daylighting
• Strategic landscaping to minimize solar gain in the
summers and encourage it in the winter
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Case Study – EE Measures Installed
Materials and mechanical systems materials
contributing to energy efficiency included:
• Radiant barrier roof sheathing
• Low E² thermally efficient windows
• Third-party HERS-rated HVAC equipment to
ensure maximum performance of the system
• Raised heel trusses for increased insulation
• A high-performing building envelope complete with
Quality Insulation Installation
• Ducts in conditioned spaces, tested and verified
for leakage
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Case Study – EE Measures Installed
In addition BRIDGE also incorporated high efficiency
ENERGY STAR® appliances and lighting:
• Refrigerators, dishwashers, and front-loading
washers and dryers
• Fluorescent lighting, light-emitting diode (LED)
exit signs, and motion sensor lights in the
community building.
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Case Study - Cost Benefit Analysis
As a result of the advanced planning and clear goals
BRIDGE exceeded Title 24 by over 17% without
significant impact on the cost of the project.
• Estimated $85,000 spent on incremental energy
efficiency upgrades ($0.71 per square foot).
• CMFNH incentives received = $38,540, reducing
net cost of EE measures to $0.39 per square foot
• Total hard costs for the project ≈ $143/sqft
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Case Study - Cost Benefit Analysis
Cost of energy efficiency upgrades only ≈ 0.27% of
hard costs!
Total Hard Cost
$17,105,000.00 (≈$143/sqft)
Incremental Energy Efficiency Cost (including CMFNH
incentives)
$46,151.00 (≈$0.39/sqft)
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Case Study - Cost Benefit Analysis
Cottonwood Creek Apartments is expected to save…
+
27,426.83 kWh every year through good design
12,445.60 kWh savings from appliances
This one project will be saving enough energy every
year to power roughly six California single-family
homes.
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Case Study – Payback
Cost of EE upgrade
Utility incentives
Net Cost of EE Measures
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$85,000
$38,540
$48,455
Annual energy savings (kWh) 39,872.43
Utility Cost (per kWh) x
$
0.14
Annual utility cost savings $5,582.14
Payback Period = 48,455/5,582 = 8.7 years
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Non-Energy Benefits of
Energy Efficiency
Non-Energy Benefits of Energy Efficiency
Beyond energy savings, energy efficiency
benefits include:
• Marketability
– Buyers and tenants value homes that are easy
and inexpensive to maintain
– As well as socially and environmentally
responsible
• Comfort
– Measures to reduce energy use also produce
more comfortable living conditions
• Public recognition
– Awards are given by numerous associations for
achievement in energy efficiency.
– Receipt of such awards may give your business
credibility and prestige
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Beyond EE – Green Measures
• Non toxic materials and finishes
– Low VOC Paints, carpet, cabinets
• Better indoor air quality
• Local and replenishable materials
– Forest Stewardship Council (FSC) certified wood
products
– Recycled materials
• Water conservation
– Landscaping
• Irrigation
• Indigenous plant species
– Plumbing & Appliances
• Dual flush toilets
• Low flow shower and sink fixtures
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Beyond EE – Green Measures
• Storm water control
– Green roofs
• Water capture
• Insulating and cool roof properties
– Permeable surfaces
• Prevent water run-off and stormwater pollution
– Greywater systems
• Onsite water recycling
• Location
– Proximity of transportation and amenities
– Low environmental impact
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Financing for Energy
Efficiency and Green
Measures
Financing Energy Efficiency
Low Income Housing Tax Credits (LIHTCs) are
awarded to new construction and rehabilitation
projects on a competitive points basis
• 155 points required to be competitive in the 4%
and 9% categories
• Maximum of eight points available for
incorporating sustainable measures, including
energy efficiency
– Of those 8 points, 6 are available for energy
efficiency
• Exceed Title 24 by at least 10% - 4 points
• Energy Star rated fans, whole house fan, economizer
cycle on HVAC system – 2 points
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Financing Energy Efficiency
• Additional discretionary threshold basis limits
boost up to 5% of the project’s basis limit.
– Exceed Title 24 by 15% or more
– Distributive energy technologies
– Renewable energy sources
– Tankless water heaters
– High efficiency condensing boiler
– Solar thermal domestic hot water system
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Financing Energy Efficiency
Federal Tax Credits for New Homes are available for
site built homes, excluding rental properties and
non-profits.
• $2,000 to builder for each home whose performance is
calculated to exceed Heating and Cooling Use of Section 404
of 2004 Supplement of the IECC by 50%)
The New Solar Homes Partnership offers rebates to
reduce (buy-down) the initial cost of a photovoltaic
system in new residential construction (single and
multifamily).
• $2.50/watt for market-rate housing
• $3.50/watt for affordable housing projects
• Project must exceed Title 24 by at least 15%
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Summary
Summary Points
• Title 24 defines the worst building allowed by
law
• Early team collaboration allows for integrated
and cost-effective decisions
E Consultant
Engineers
Owner/Dev
Financing
Builder
• Consider
lifecycleArchitect
cost, including
non-energy
benefits
• Local, statewide and federal financial
incentives are available to offset incremental
costs of energy efficiency upgrades
• Use a performance approach to find the best
package of cost-effective measures for each
unique project
• Third Party verification allows for performance
credits and quality assurance
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Resources
Resources
Program Information
• US EPA ENERGY STAR® Program
– www.energystar.gov/homes
• California Multifamily New Homes Program: PG&E
– www.h-m-g.com/multifamily
• California Advanced Homes Program: SCE,
SDG&E, SoCalGas
– http://www.sce.com/b-rs/bb/cali-new-homes/
– http://www.sdge.com/builderservices/newHomes.shtml
– http://www.socalgas.com/construction/ahp/
• California Multifamily Energy Efficiency Programs
– www.californiaenergyefficiency.com
– www.fyppower.com
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Resources
General EE Resources
• Energy Design Resources
– www.energydesignworkshops.com
• California Energy Commission
– www.energy.ca.gov
• California Association of Building Energy Consultants
(CABEC)
– www.cabec.org
• California Multifamily Housing Consortium
– www.seiinc.org/mfconsortium.html
• Partnership for Advancing Technology in Housing (PATH)
– www.pathnet.org
• US Green Building Council (USGBC)
– www.usgbc.org
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Resources
Verification and HERS rating
• California Home Energy Efficiency Rating System
– www.cheers.org
• CalCERTS
– www.calcerts.com
• CBPCA
– www.cbpca.org
• Resnet
– www.natresnet.org/herseems/ratingmethod.htm
• Building Commissioning Association
– www.bcxa.org
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Resources
Finance
• Energy-Efficient Mortgages
– www.pueblo.gsa.gov/cic_text/housing/energy_mort/ener
gy-mortgage.htm
• Solar and Wind Financial Incentives & Tax Credits
– www.californiasolarcenter.org/incentives.html
• Energy Efficiency-Based Utility Allowance
– www.designedforcomfort.com
• California Housing Finance Agency (CalHFA)
– www.calhfa.ca.gov/multifamily/financing/index.htm
• EnergyWi$e Construction Funding Directory
– www.fundinggreenbuildings.com
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