ENERGY STAR® Homes version 3 - Efficiency Vermont

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ENERGY STAR® Homes version 3 - Efficiency Vermont

ENERGY STAR® Homes version 3

Designing and Building to Meet the 2011 Changes

1


Big Changes for Residential New Construction

• When codes change, ENERGY STAR must change to stay ahead

• VT’s energy code is being revised to align with IECC 2009

ENERGY STAR v3 aims to remedy the most persistent flaws found

in Version 2 buildings

• Flaws that undermine the perception of quality in an ENERGY STAR home

• EPA is steadily moving ENERGY STAR Homes toward Net Zero

Energy

• Reduce energy demands to the point that on site renewables can satisy

residual loads

ENERGY STAR defines an efficient home

• As materials and craft evolve, the concept of “efficient” keeps moving to the

front of the line

2


ENERGY STAR is a Marketing Tool

• A way to express to your customers what you are offering

• A way to distinguish your home from an existing home or

other new homes that lack a performance standard

• A well-recognized label guided by building science and broad

industry consensus

• Higher value stemming from…

• Savings measured and verified

• Air quality strategy

• Durability strategy

• Comfort strategy

3


ENERGY STAR is 3 rd Party Verified

Confidence for home buyers

• Assurance that house truly meets the standard

• Performance tested for accuracy

• Independent verification instead of just labels and claims

4


Version 2 vs. Version 3

• Currently under ENERGY STAR Version 2

• Performance threshold, testing, air sealing and air barrier

requirements

• A little bit more stringent than Vermont’s Energy Code

• Version 3

• Requirements for: insulation, windows, thermal bridging ,

ventilation, air conditioning, lighting, water management

• Version 2, minimum challenge vs.

Version 3 highly challenging

5


Version 3 is an

invitation to

innovate.

The changes you make in response to

the challenges will result in faster,

cheaper, easier construction, and

better performance.

6


Automotive X Prize:

An invitation to

innovate

ENERGY STAR v3 has a slightly less

impressive reward, but you still earn

your spot in a small, proud group

7


Defining Efficient Homes

EPA has defined an efficient home as having these features

(see following slide)

The three features on the left all contribute to occupant

comfort. These are the critical components to get right. An

uncomfortable homeowner by definition does not live in an

energy efficient home.

ENERGY STAR has strategies to assure each of the basic

features of an efficient home.

8


ENERGY STAR v3 is challenging, but

Efficiency Vermont is here to help…

• Answers about the requirements

• Calculate a home’s target index

• Determine whether an assembly meets

the standard

• Plan review

• Performance testing

• Verification

Vermont ENERGY STAR Homes is presented

in partnership with Vermont Gas Systems.

Requirements presented here are for ENERGY STAR

homes built in Vermont

10


Timeline for transition to Version 3

• 2011 transition phase: Version 2.5

• Any project enrolled and completed in 2011 must meet Version 2.5

• Version 3 fully in effect 2012

• Any project completing after January 1, 2012 must meet all the

requirements of Version 3

• New Efficiency Vermont service: Energy Code Plus

• A stepping stone for builders who aren’t ready for the Version 3

challenge

• Assistance meeting VT’s new energy code

• All new enrollments eligible for this service starting in 2011

11


Following is an explanation of the

ENERGY STAR v3 standard as an

Efficiency Vermont service.

The information is organized for design

considerations. An ENERGY STAR

home starts with design. With

Version 3 it is unlikely a home could

be made compliant that was not

designed for compliance.

12


More information can be found on the

ENERGY STAR for Homes checklists,

linked through the Efficiency

Vermont website

www.EfficiencyVermont.com

For Partners

Residential New Construction Partners

13


ENERGY STAR version 3

HERS Index (Energy Rating Score)

• Most significant influences on the index

• House size

• Glazing percentage

• Air tightness

• Insulation levels

• Heating/hot water efficiency

• Lighting and Appliances

• Custom index for each home; likely between 60 and 70 points

(Maximum index under Version 2: 80 pts)

• Large homes must score better

14


Size Adjustment Factor

If your house is larger than the benchmark

home for the number of bedrooms, an

adjustment factor is applied to the target

HERS index, with the effect that it is harder to

meet ENERGY STAR with a large home. The

adjustment generally results in a 1-4 point drop

in the index.

Below grade spaces and bedrooms not included for the purposes of determining the Size Adjustment Factor.

15


Maximum Air Leakage: 3 ACH50

Max blower door #’s

16


Lighting

Appliances*

• 80% ENERGY STAR

lighting

• High use locations

• Fluorescent or LED

• Pin-based or screw-in

ENERGY STAR…

• Heating and

• Cooling and

• Refrigerator and

• Dishwasher and

• Clothes washer

*An incentive is available for Tier II or Tier III appliances. See last slide.

17


ASHRAE 62.2 - Ventilation

Whole House Ventilation

Spot Exhaust Ventilation

• Exhaust fan or balanced

system

• Sized for people and

square feet

• Programmable control

• Delivers adequate fresh

air

• Kitchen

Exhaust flow 5 air changer per

hour, kitchen volume OR

100 cfm plus vented hood

• Bathroom

• 50 cfm (20 cfm if continuous

operation)

* Required documentation: report indicating system type, design.

18


Ventilation Air Inlets

• 10’ from contamination sources

• 4’ above grade

• 1/2” rodent screen

HRV inlet not permitted at

band joist above basement if it

is close to grade.

Only for ventilation air inlets. Combustion air inlets must meet fuel codes.

19


Mechanical: Heating, Cooling, DHW

Including fireplaces and woodstoves

Power vented or

Sealed (combustion air is drawn from outside)

Energy Code has new definition of tight-fitting doors for solid fuel appliances.

20


Slides 22-26 and 29-30 cover design of the

ducted heating and cooling system. The

firm that designs the heating and cooling

system must sign off on these items, and is

responsible for providing documentation on

the design of the system.

All design documents and signed checklist

are to be provided to Efficiency Vermont at

the rough inspection.

21


Mechanical: Ducted Heating and Cooling

(Following slides through page 34 for ducted heating and cooling systems only.)

• Accurate load calculation

• Efficient filtration

• Performance testing

• AC charge

• System flow

• Room balancing

• Duct design

• Duct leakage

ENERGY STAR covers these aspects of heating and cooling design and

installation. There are additional requirements as part of VT’s Energy

Code.

22


Mechanical: Load Calculations

• Design temperatures from ASHRAE

• Correct size of house

• Correct number of bedrooms

• Correct solar orientation

• Correct window area

• Correct window performance value

• Accurate building leakage

• Correct filter static pressure

• MERV 6

* Required documentation: heat load report.

23


Mechanical: Load Calculations

Correct design parameters will be verified by

the Energy Rater.

24


Mechanical: Efficient Filtration

• MERV 6 filter or better

• Well-designed filter slot

• Filter slot must not allow air

to leak past filter

Note: filter efficiency affects

design of ducts. We recommend a

note by the filter door

“This system designed for MERV

X filter.”

25


Mechanical:

Equipment Selection per Manual S

• Manual S or OEM recommendation

• Within 95-115% design load

* Required documentation (for AC only): AHRI certificate.

26


Slides 28 and 31 cover performance testing

of the ducted heating and cooling system.

The installation contractor must sign off on

these items, and is responsible for

providing documentation on the

commissioning of the system.

Performance testing records and signed

ENERGY STAR checklist are due at the final

inspection.

27


Mechanical: Performance Testing

Required tests:

• Refrigerant Charge

• Subcooling deviation no greater than 3ºF

• System air flow

• Within 15% of design value

28


Ducts: Distribution Design

• Ducts and air handler located fully within thermal envelope

• Duct system designed and installed per Manual D

29


Ducts: Distribution Design

Manual D is a detailed design with room-by-room air flows, duct

length and size, connector type and termination size, location

and type. Ductilator design is not a substitute for Manual D.

30


Ducts: Performance Testing

• Static pressure measured

• Test hole must be labeled for comparison testing by rater

• Room air flows measured

• Within 20% or 25 cfm of design flow

• Pressure balanced bedrooms

Return air path OR

Adequately-sized return duct

• 1 sq. in. per cfm of measured supply OR

3 pa pressure difference to hallway

• As measured by the rater

31


Ducts: Leakage

• Total duct leakage 6 cfm per 100 sf floor area

• 8 cfm per 100 sf floor area for homes 1200 sf

• Duct boots sealed to cut out

Seal here

32


Great duct sealing effort, but if you seal after

installation ,there will always be areas that

cannot be sealed. Assemble and seal ducts

before they are installed.

33


This kind of duct sealing effort

categorically will not meet the

ENERGY STAR leakage

threshold. Ducts leak at every

factory seam and all sides of

every joint.

34


Mechanical Documentation

To be provided to your Rater

Ventilation system design report

• For all homes

Manual J Report

• For ducted heating and cooling

AHRI Certificate

• For air conditioning

Balancing Report

• For all ducted heating and cooling

• # Returns each room

• Measured flow rate each terminal

35


Site

• Grade sloped to drain away from house

• Impermeable surfaces sloped away from

house

• Protect your materials!

•Materials with visible signs of water

damage or mold prohibited

36


Foundation: Slab

• Exposed slab insulated at edge

• R-15

• Aligned with framed wall above

• R-15 under heated slabs

• Capillary break

4” aggregate + polyethylene or polystyrene OR

4” sand + geotextile matting + polyethylene or polystyrene

37


Where slab is within 12” of grade, insulation

must cover edge of slab and be aligned with

insulated wall above.

38


This slab

insulation does

not align with the

insulated wall

39


… a particularly disappointing failure to

align slab edge insulation with the

insulated wall above

40


Two other elegant ways to

insulate the slab edge…

Insulated concrete forms

“Pinkcore” and others

41


Foundation: Basement

• Basement walls R-15 continuous insulation or R-20

in a framed wall

• No vapor barrier with fiber insulation on interior of

below-grade walls

42


The next several slides are about

framed assemblies. So, let’s take

a moment to define…

43


Air Barrier

• Blocks air flow

• Durable

• Not Kraft-facing or paper

• Not easily torn

• Sealed

• Rigid material strongly

recommended

44


Cavity Insulation

• All insulation must meet Grade I quality installation (Grade II

permitted with R-5 or greater continuous insulation)

• No gaps

• < 2% area compressed

• Minimum R-6 behind insulation displacement

• Nailers

• Vent stack

• Speakers, etc

• Insulation must be dry before being enclosed

45


Insulation Grading

flaws

Grade I

Enclosed on 6 sides

In full contact with

enclosure

No gaps

< 2% area compressed

• Maximum 30% depth

compression

46


Compression resulting in a void not permitted

These areas require special attention:

• Blocking (for cabinets, stair rail, etc)

• Electrical boxes or wires

• Nailers

• At top and bottom of framing cavity

• Plumbing stack (best to keep these out of insulated walls)

• Thickened walls

• Recessed light fixtures

Compression behind blocking is not considered a flaw, but best

to keep blocking to a minimum in order to allow full insulation

All of every insulated cavity must be installed well.

47


Batt is slit to

conform to

obstacles in the

cavity

Simple framing is easy to

insulate. Design for good

insulation installation.

Score batt in

order to relieve

the batt to the

face of the

framing.

Cellulose often

installs well

around

irregular

framing

48


Framed Floors

• R-30

• Fully enclosed insulation cavity

• Floors over garages

• Room trusses

• Cantilevered floors

• Interior insulation enclosure at band

• Mudsill gasketed and sealed

• Sill seal or better gasket

• Plus caulk or spray foam

49


Insulation enclosure at band. Optional

fiberglass behind. This needs to be sealed in

place to count as an interior air barrier.

50


Windows and Doors

• U factor .32 or better

• 15 s.f. exempted for decorative windows

• One solid door exempted

• Fully flashed rough opening

• Rough opening sealed

51


Window Flashing

• Requires all 3 parts

A. Pan flashing

B. Jam flashing

C. Head flashing

• All lapped correctly to

shed water

52


Window Flashing

Pre-formed pan

flashing.

Comes in 3 pieces

for adjustability.

Avoids hole in

flashing at critical

corner.

If installed after

housewrap,

separate jam

flashing required

in order to lap

over pan flashing.

53


Window Flashing

Very nice site-built

pan flashing with

back-dam to

prevent collected

water from

dribbling into the

house.

Still needs

separate jam

flashing.

54


Strip of housewrap as

release paper under

peel n’ stick.

Some roll products can be installed in a single

piece without cutting. This one is installed before

housewrap. In this case the housewrap can turn

into the rough opening and act as the jam flashing.

55


Walls

Complete weather resistive barrier

• Lapped to shed rain

• Integrated with flashing

56


Framed Walls

• R-20 cavity insulation OR R-5 continuous + R-13 cavity

• Fully enclosed insulation cavity

• Balloon-framed gable walls

• Room truss

• Double walls

• Kneewalls

• Different ceiling heights

• Behind…

• Showers, tubs, fireplaces, skylight shaft

• Party or common wall sealed at exterior (ceiling and wall)

• If structural masonry party wall penetrates envelope, it

must be insulated on both sides

57


Elegant way to insulate knee wall of room truss:

• Build sheathed, framed wall with top plate

within truss

• Insulate interior wall

58


Framed Walls

• Reduced Thermal Bridging required

R-5 continuous insulation

• Exterior foam sheathing

• Double framed wall with insulated gap OR

Advanced framing

• 24” oc for 2X6

• Insulated headers, corners and wall intersections

• Limited framing at windows and doors

• No structurally-unnecessary studs OR

Solid walls

• SIP’s, ICF’s, etc

59


Ceilings

R-49 with R-38 at inside of perimeter wall OR

R-38 throughout

Too little insulation

at perimeter.

Overhanging truss

one way to meet

requirement.

60


Ceilings

• Fully enclosed insulation cavity

• Exception for topside of attic insulation

• Windwash protection at eve

• Sealed fan cutouts

• Air tight recessed lights

• With air tight trim kit

Strapping under insulation does not

meet requirement. These gaps will

undermine insulation performance.

61


Windwash protection

prevents roof ventilation

from washing through

perimeter of attic insulation.

Adequate clearance for R-38

insulation over top plate.

62


Ceilings

• Shafts sealed

• Utility shafts

• Chimney surround

• Dropped ceilings and soffits insulated

• Attic access hatch

• Insulated per ceiling

• Gasketed or sealed

• Party or common wall sealed at attic

Poorly sealed attic hatch shows

leakage under negative pressure

and infrared thermography.

63


Architectural soffits particularly

difficult to seal and insulate.

Best to install ceiling drywall

before framing soffit.

64


Drywall

• Non-paper-faced wall board behind tub-shower

• Exception for 1-piece tub-shower

• Drywall sealed to top plate at attic

Seal after drywall is installed

or before (preferable due to

more continuous seal.

65


Top plate sealed from attic acceptable, but

interrupted at each truss.

Construction adhesive not accepted due to poor

longevity. Flexible sealants required.

Seal partition walls and perimeter walls.

66


Roof

• Flashing

• Step flashing and kickout at roof-wall

• Integrated with house wrap

• Gutters required

• At-grade roof-water collection system

acceptable as alternative

• Self-sealing membrane at

• Valleys

• Eves > 2’ above wall

67


SIP’s

Joints sealed AND taped

68


Builder Orientation and

HVAC Accreditation

Builder must be an ENERGY STAR Partner AND have

completed the Version 3 orientation in order to have a

home labeled with the Version 3 label (starting in 2012).

Become an ENERGY STAR Partner and take the Version 3

orientation at My ENERGY STAR Account

www.ENERGYSTAR.gov

For homes with ducted heating or cooling, the HVAC

contractor and design professional must be part of an EPAaccepted

Quality Installation program. ACCA currently is

the only organization offering such a program.

https://www.acca.org/industry/quality/

69


ENERGY STAR v3 is a Team Effort

You can’t pull it off if you start planning

after you get the ball.

70


ENERGY STAR v3 is a Team Effort

Understand the ENERGY STAR standard

before you sign contracts; Efficiency Vermont

can help you understand the potential

stumbling blocks.

Meet with your critical subs so everyone

knows who is responsible for meeting each

requirement.

71

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