deep energy retrofits: california case studies · solarwaterheater; pumps appliance: fridge,...

DEEP ENERGY RETROFITS:

CALIFORNIA CASE STUDIES

Jeremy Fisher & Brennan Less – LBNL

Aug 16, 2011

LBNL Deep Energy Retrofit Monitoring

10 residential retrofits aiming at 70% or more

energy savings.

Goal: To show how energy is actually being

used in these northern California deep energy

retrofit homes.

End-use energy monitoring

1 year minimum monitoring period

How do we talk about performance?

Energy per house vs. per square foot vs. per occupant

Site vs. Source energy

Separation of renewable energy

Nearly all case studies are significant remodels, not solely energy retrofits or home performance upgrades

Changes in square footage and physical layout

Issues with pre-retrofit vs. post-retrofit comparison

Ownership/Access to utility data

Comfort

Occupancy

Weather

Issues with end-use monitoring

Circuit panel layout and combined electrical loads

Monitoring equipment limitations

Complex combined HVAC/DHW/Solar systems

Load calculation by subtraction is problematic

Monitoring Equipment

Project Locations

P1 Project Description

1904 Craftsman Bungalow

Berkeley, CA

Pre: 960ft2 Post: 1,630ft2

The existing home was un-insulated with one natural gas floor heater on the 2nd level

The house was lifted, and the ground floor was rebuilt to legal height

The retrofit was guided by the European Passive House design principles

4 bedroom, 2 bath, 4 occupants, home office

P1 Retrofit Description

P1 Retrofit Achievements

Conditioned entire home, greatly improving comfort

Doubled usable/legal space

Addition of home office

Addition of 2 teenage occupants

Aesthetic improvements

Pioneered Passive House retrofit techniques in the Bay Area

Significant energy reductions

P1 Historical Utility Bill Data

Before Retrofit

After Retrofit After Retrofit

0

2000

4000

6000

8000

10000

12000

14000

2005-2006 2008-2009 2009-2010

To

tal A

nn

ual

En

erg

y U

se (

kW

h)

31.7% Reduction in

energy use

P1 Energy Use Data

Whole House Energy Usage

0

200

400

600

800

1000

1200

1400

Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11

kW

h

Total Gas Consumption

Total Electrical Consumption

P1 Energy Use Data

0

50

100

150

200

250

300

350

400

450

500

Hot Water: Tankless DHW

HVAC: Wall Heaters

Plugs: Whole House

HVAC: ERV Appliance: Dish Washer, Stove, Clothes Washer

Lights: Whole house

HVAC: Kitchen Range Hood

kW

h

Oct-10

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11Does not include

Gas Cook Top


1936 English Tudor Revival-Style Home

Palo Alto, CAPre: 2,780ft2 Post: 2,780ft2

The existing home was

considered architecturally

significant, and efforts were

made throughout the

project to maintain its

historical character.

5 bedroom, 3 bath, variable

occupancy, home office


Conditioned entire home, adding cooling

Maintained historical character

No expansion of building footprint

Was a high energy user, so even though it is

still higher than other projects, the savings are

significant


Before Retrofit

After Retrofit

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

Mo

nth

ly T

ota

l E

nerg

y U

sg

ae

(kW

h)

38.5%42.5% 50.2% 43.9% 64.8% 70.1%

65.7%

69.4%60.2% 55.4% 30.1%

15.2% 28.8%

44.9%

41.8%

62.4%

66.5%

58.1%

54.9%

28.5% 16.6%

-6.1%

-1000

-500

0

500

1000

1500

2000

2500

3000

3500

4000

Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11

kW

h

Total Electricity Consumption

PV Production

P2 Energy Use Data

Percentage

reductions from

pre-retrofit usage

P2 Energy Use Data

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

2100

2200

HVAC&DHW: HeatPump,

Hydronic Pump

Plugs: A/V, Server (Hydronic Pumps)

HVAC: Air Handlers

Whole House Lights

Appliances Plugs HVAC: Range Hood

kW

h

Sep-10

Oct-10

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11

Electric resistance tank water heater

used during heat pump replacement

Malfunctioning Heat

Pump Unit

2 Pumps

eliminated from

HVAC


Two 1958 ranch-style homes connected by a

covered breezeway

Pre: 1,933ft2 Post: 2,342ft2

The two separate structures were connected by enclosing the breezeway, forming a U-shaped home with a central courtyard

3 bedroom, 2 bath, 1 Occupant, home office

Image courtesy of www.solar-knights.com


First certified Passive House retrofit in the

country

Low heating energy despite challenging U-

shaped layout with high surface to volume

ratio

Turned two relatively undesirable homes into

one beautiful, highly energy efficient home.

Serves as a regional model for deep energy

retrofits

-600

-400

-200

0

200

400

600

800

1000

Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11

kW

h

PV Production


Total Electrical Consumption

P3 Energy Use Data

Invalid Net-

Metering Data

Valid Net-

Metering Begins

P3 Energy Use Data

0

50

100

150

200

250

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11

Temporary Use

during Mini-Split fix


1940’s Bungalow

Petaluma, CAPre: 1,540ft2 Post: 2,510ft2

This retrofit was carried out in 3 phases:

1- In 1998 prior to moving in

2- In 2004 renewable energy

was added

3- In 2010 a structural/seismic

retrofit

A 4th phase is in planning, including a solar combisystemwith a back up biomass boiler for total carbon neutrality.

2 bedroom, 2 bath, 2 occupants, home office


Staged approach to retrofit, learning from

experience and experimentation

Pre-retrofit utility data is not available, yet

major energy reductions were achieved from

phase one to phase three

Added home office

Special attention to improving IAQ and other

sustainable practices

Added 1/3 of floor area while significantly

reducing energy use


PV Installed

0

2000

4000

6000

8000

10000

12000

14000

2001 2002 2003 2004 2005 2006 2007 2008

To

tal A

nn

ual

En

erg

y U

se (

kW

h)

64.9% Reduction in

energy use (including PV)

-1000

-500

0

500

1000

1500

2000

2500

Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11

kW

h

PV Production



P4 Energy Use Data

Net-Site Energy

Exporter!

Total gas does not

include dryer

P4 Energy Use Data

0

100

200

300

400

500

600

700

800

HVAC: Furnace DHW: Tankless Appliance: Range, Fridge, DshWshr, Fan

Plugs: All but kitchn and office

Office: Plugs, Lights, DSL

Router

Plugs: Ktchn, Micro, Study,

MtgRm

Appliance: WellPmp, Vacm,

Wshr/Dryr

Transportation: Electric Car

kW

h

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11

All Electric Nissan

LEAF



San Mateo, CA

Pre: 3136ft2 Post: 3288ft2

House within a house concept, using kitchen and rear zone as primary living space in winter. Insulated entire home, maintaining architecturally significant interiors, increased comfort and hope to achieve 1000 home challenge with future PV installation.

3 bedroom, 2.5 bath, 2 Occupants


House within a house concept

Preserved existing interior

Low energy user behavior (except for cooking)

Seismic, foundation and drainage

improvements

High quality construction practices


0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

kW

h

Total Energy Usage (kWh)

Austerity Efforts50.4%

Reduction!

P7 Energy Use Data

0

50

100

150

200

250

300

350

400

450

kW

h

May-11

Jun-11

Jul-11

Does not include Hot

Water

Pilot Lights and Lots of

Cooking



Oakland, CA


Super Green Retrofit–LEED Platinum rated, greywater, rainwater, sustainable materials and landscaping, low flow fixtures + energy efficiency


Source: http://www.elledecor.com/home-remodeling/articles/greenest-little-house-america



Super “Green” Retrofit

LEED Platinum

Maintained historical character of interior

Did not increase building footprint

-1000

-500

0

500

1000

1500

2000

2500

3000

Mar-11 Apr-11 May-11 Jun-11 Jul-11

kW

h


PV Generation


P8 Energy Use Data

Missing Gas

Data

P8 Energy Use Data

0

500

1000

1500

2000

2500

Solar Combined Space Heat/Hot

Water

Appliances: Kitchen

Plugs: Kitchen, Bath and Dining

Plugs: Crawl Space (Hydronic and Greywater

Pumps)

Lights: Whole house + Bdrm

Plugs

Appliance: Washer/Dryer

Plugs: Garage (Fridge and

Hydronic Pump)

kW

h

Mar-11

Apr-11

May-11

Jun-11

Jul-11

High Efficiency, Solar Assisted Boiler

using far too much gas


1998 Tract Home

Folsom, CA


SMUD Advantage home with a significant energy upgrade and a kitchen remodel.

Increased insulation, air sealed, lighting retrofit and an extensive HVAC overhaul.



Total kWh savings: 59%

Total therm savings: 41%

Total electric and gas cost savings at 2008

rates: $1,260 per year

Air infiltration reduction by 36% cfm50

Low cost, minimally intrusive and very

successful retrofit


0

1000

2000

3000

4000

5000

6000

kW

h

Pre-Retrofit (4-year average)

Post-Retrofit

47.7% Annual

Energy Reduction

P9 Energy Use Data

0

50

100

150

200

250

DHW: Tank Gas Heater

HVAC: A/C Lights and Plugs: Misc

Appliance: Washer/Dryer

HVAC: Furnace

Plugs: Kitchen (Fridge) Dining

Appliance: DishWasher, Disp, Micro

Appliance: Oven

Misc: XMas Lights, Irrigtn,

FireAlrm

kW

h

Jul-11

Mixed Occupancy during this

period due to vacation


1938 Cottage

Pacifica, CA


Family built “Shamrock Shack” remodeled for retirement with goals of resource and energy efficiency, while maintaining original charm with modern comforts.


Images courtesy of Jim Kremer and regreenprogram.org


Greatly increased comfort of home

Changed interior layout to be far more

functional

Installed skylights to improve natural lighting

Material re-use

Water efficient fixtures

0

10

20

30

40

50

60

Plugs: All HVAC: SolarWaterHeater;

Pumps

Appliance: Fridge, Dishwasher, Oven

Lights: Phone and Aquarium

Lights: Outside, Jungle Rm, Baths

Appliance: Washer and Dryer

kW

h

Jul-11

P10 Energy Use Data

Data represents Unoccupied Energy Use

Occupants were on vacation most of month

Net Total Energy Use in July was -252 kWh

Project Comparison-Air Tightness

271 292

1455

1983

2276 2397

5336

1510

50

100

150

200

250

300

350

P1 P5 P10 P4 P2 P8 P7 P3 P6 P9

Sq

uare

In

ch

es

Effective Leakage Area

CFM@-50pa

Factor of x29 from

smallest to largest!

Total Energy Consumption

0

500

1000

1500

2000

2500

3000

3500

4000

P1 P2 P3 P4 P8

kW

h

Sep-10

Oct-10

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11

Energy Per Occupant

0

200

400

600

800

1000

1200

1400

1600

1800

2000

P1 P2 P3 P4 P8

Sep-10

Oct-10

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11

Energy Per Square Foot

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

P1 P2 P3 P4 P8

En

erg

y U

se I

nte

nsit

y

Sep-10

Oct-10

Nov-10

Dec-10

Jan-11

Feb-11

Mar-11

Apr-11

May-11

Jun-11

Jul-11

Final Thoughts

Deep savings are achievable using a variety of

current technologies

Simple approaches are better than complex

ones

Low energy user behavior is essential to

success

Once you reduce heating and hot water,

discretionary energy should be targeted for

reduction

deep energy retrofits: california case studies · solarwaterheater; pumps appliance: fridge,...

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