How Insulation Affects Your HVAC Efficiency

Your HVAC system and insulation are teammates. Improving one without addressing the other limits results.

How Insulation Works

Insulation slows heat transfer between your home and outside: - In summer: Keeps heat out - In winter: Keeps heat in - Always: Reduces HVAC workload

The R-Value Basics

R-value measures insulation effectiveness. Higher is better.

Bay Area Recommendations - Attic: R-38 to R-60 - Walls: R-13 to R-21 - Floors: R-25 to R-30

Many older Bay Area homes have less than these levels.

Signs of Inadequate Insulation

High Energy Bills If bills seem excessive for your home size and habits, insulation may be lacking.

Temperature Variations Rooms feel very different temperatures or change rapidly with outdoor conditions.

HVAC Runs Constantly System can't maintain temperature because heat is transferring too quickly.

Ice Dams (Less Common Here) In areas with snow, poor attic insulation can cause ice dams.

Impact on HVAC System

Oversized Systems When insulation is poor, systems are often oversized to compensate. This causes: - Short cycling - Poor humidity control - Uneven temperatures - Higher costs

Undersized After Improvements After insulation upgrades, your current system may actually be larger than needed—good for comfort but not efficiency.

Which to Improve First?

Insulation Usually Comes First Adding insulation often costs less than HVAC replacement and: - Benefits any heating/cooling method - Lasts indefinitely - May allow smaller HVAC system

If Replacing Both Get insulation work done first, then size new HVAC to the improved building.

Cost and ROI

Attic Insulation - Cost: $1,500-3,500 for most homes - Savings: 10-25% on heating/cooling - Payback: 3-8 years

Wall Insulation (Existing Walls) - Cost: $2,000-5,000+ for blown-in - More disruptive installation - Longer payback

Professional Assessment

An energy audit can identify: - Current insulation levels - Priority improvement areas - Expected savings - Incentive eligibility