Green Needham Efficiency Program Breakdown of program road map
General Overview of Steps for the Program • Energy Assessment • Building Envelope Tightening • Insulation Measures • System Upgrade
Step 1 Step 2 high priority Step 2 lower priority High NSL priority level Low Adjusted internal rate of return (after subsidies) across life of measure Next Step Living Priority of Service Rationale Savings off energy bill (assumes no interaction between improvements) Step 1 = 8-12% Step 2 high priority = 10-20% Step 2 lower priority = 10-30% Total = 60% With interaction, total savings =~40% * Measures done across multiple steps Savings figures calculated using TREAT software; Costs based on web searches and consultations with HVAC and insulation contractors; key assumptions for sample home used in TREAT analysis: 3000 sq. ft home, with 4 occupants; Base CFM50 of 3500 improved to 2800 after air sealing; Boiler heated with Nat Gas initial efficiency of 80%, replaced with boiler with 90% efficiency; Water heater storage tank with .56 EF replaced with storage tank with .85 EF; 12 bulbs replaced with CFLs; Hot water initial setpoint of 135 improved to 120; Numbers are meant to be directional
Home Assessment • NSL 3 Hour visit • Blower Door • Infrared • Implementation of weatherization measures • System efficiency testing • 10-20% Energy savings • Average carbon footprint reduction = 10% • Report • Detailed report that outlines measures taken and how the house performed before the visit and then after • Recommendations • The report gives the customer a list of issues to be addressed in the home based on a priority level and cost effectiveness.
NSL Average Carbon Reduction performance results:Most recent 100 customers = 10% Typical savings measures Annual household emissions (lbs CO2)* 1) Insulating hot water pipes 2) Installing low flow shower heads and faucet aerators 22,880 lbs/yr 1) Installing CFLs • Air sealing • Insulation Average 10% CO2 reduction from Step 1 service *Source: Source: EPA’s Unit Conversions, Emissions Factors, and Other Reference Data Report (Nov 2004) Conversion to CO2 based on the following ratios: 1.34 lbs of CO2 per kwh, and 12 lbs of CO2 per therm (Source: eia.doe.gov)
Building Envelope – Air Seal to Increase the Overall Home Efficiency • Follow up work to increase the efficiency of the home • Focus on the most important areas of the home • Attic – seal penetrations for heat loss • Basement – seal to prevent air infiltration • Living space – seal all areas of air infiltration around windows, doors, baseboards, etc.
Building Envelope - Insulation • Diagnostic Assessment will recognize the need for insulation needs • Areas of interest: • Attic – insulate this area either on attic flat or the roof slope • Considerations include HVAC systems or living space • Walls – many older homes have little or no insulation in the walls. Insulation can be put in through blowing in walls either outside or inside
System Efficiency – Upgrade vs. Tuning • Efficiency testing done at diagnostic • Recommendation of efficiency • Weather response controls • Clean, Tune, Evaluate • Triggers for system upgrades • Older than 20 years • Efficiency below 70% • General interest in changing to other options – solar, geothermal, other efficiency options for hot water, etc.
Budget Pricing for Each Step of the Needham Program • Assessment: $670 • Air Sealing: $1,500 - $3,500 • Attic Insulation: $2,500 - $7,000 • Wall Insulation: $2,500 - $7,000 • System Tuning/Simple Efficiency Measures: $120 - $1,500 • System Replacement - $8000 - $20,000