Indra's Energy+ Household

This projects describes the steps taken to retrofit an exsiting single family home in Cupertino California to be net energy positive including daily transportation needs. The house has maintained net energy positive status for 5 years straight showing the sustainability of the approach. No major sacrifices were made in the comfort and convinienece of the household members in the process. 

Quick Facts

General

Location
18870 Barnhart Avenue
Cupertino, CA95014
United States
Building Type Single-family residence
Project Type Net Exporter
Basis of Performance Claim Verified,
Bedrooms 4
Conditioned Floor Area 2 170

Energy Summary

Energy Data Type Measured,
Renewable Energy System Type(s) Photovoltaics,
Ratings
Annual renewable energy generated 15 500

Envelope and Mechanicals

Subslab assembly
Foundation wall assembly
Above grade wall assembly
Door Assembly
Air Changes per hour, ACH50

Project Team:

Other Team Members:

Ratings:

Awards:

Completion

Completion Date: Tuesday, December 20, 2011

Scope

Type of Construction Renovated,
Number of buildings 1
Floor area of each building 2 670
Bedrooms 4
Stories 1
Conditioned Building Volume 20 000
Conditioned Floor Area 2 170

Location and Climate Details

Single-family residence

Address
18870 Barnhart Avenue
Cupertino, CA95014
United States
Location Type Suburaban
Climate Region Zone 4
Köppen Climate Type Csb
Lat. / Long. POINT (-122.001994 37.315261)
Elevation 240
Solar Insolation 5.35 kWh/m2/day
Annual CDD and Base Temp 30 | 80
Annual HDD and Base Temp 2649 | 65

Site

Site Conditions:

previously developed land,

Site Description:

Normal suburban plot about 6000 sq ft. Street has houses on both sides. Backs to another similar house on a similar street at the back.

Monthly Energy Data and Utilities

Energy Data Type: Verified,

Electric Utility: PG&E

Gas Utility: NA

Renewables and Energy Balance

Renewable Energy Sources:Renewable energy is generated within the building footprint (e.g. solar PV on the roof),

Renewable Energy System Description & Details: 40, 295 W Canadian solar mono-crystalline modules (CS6X-295M) meted with a Fronius 11.4 KW single phase inverter. The array faces 40% east, 40% west and 20% south. Half of the array is equipped with Tigo optimizers to optimize output.

Annual renewable energy generated 15 500
Annual Renewable Energy Generated Data Type Measured,
Power Rating 11 800Watts
Renewable Energy System Type(s) Photovoltaics,
Source of Annual Production Data Metered through remote monitoring and also displayed at the inverter panel.

Walls and Roof

Subslab assembly
Subslab R-value
Slab edge assembly
Slab edge R-value
Foundation wall assembly
Foundation wall R-value
Above grade wall assembly
Above grade wall R-value
Cathedral ceiling assembly
Cathedral ceiling R-value

Windows and Doors

Window Assembly:

Door Assembly:

Average window U-factor
Door U-Factor
Door Area

Mechanical Systems

Space cooling - Manufacturer & Model
Space heating - Manufacturer & Model
Domestic hot water - Manufacturer & Model
Domestic hot water - capacity
Ventilation - Manufacturer & Model
Lighting Manufacturer and Model
Lighting Efficiency
Mechanical Equipment Installation Details and Comments

Envelope

Air Changes per hour, ACH50
Air Changes per hour, CFM50

General Process

Design for Adaptability:

Software Tools

Software Tools:

General modeling information:

Lessons Learned

Outcome of Project Goals:

Discrepancies:

Rebates and Financial Incentives

Federal incentives
Local incentives
State incentives
Utility incentives
Other incentives
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