Weatherization is the process of sealing air leaks, adding insulation, and improving thermal envelope integrity to reduce energy consumption for heating and cooling by 15-30%. This foundational energy efficiency measure decreases HVAC system runtime, lowers operating costs, and improves indoor comfort by eliminating drafts and temperature inconsistencies. Weatherization is among the most cost-effective improvements, with payback periods of 3-7 years.
Key Components
Air sealing targets cracks around windows, doors, electrical outlets, and penetrations, reducing infiltration from 8-12 air changes per hour to 3-6 ACH. Insulation upgrades to attics (R-38 to R-60), walls (R-13 to R-21), and basements (R-10 to R-21) prevent heat transfer. Weatherstripping, caulking, and gasket replacement eliminate 30-50% of uncontrolled air leakage. Window and door upgrades to double-glazed units with low-emissivity coatings reduce U-values to 0.25-0.35 Btu/hr-ft²-°F.
HVAC Impact
Improved building envelopes reduce heating and cooling loads by 20-35%, allowing smaller HVAC system installation. Tighter envelopes require mechanical ventilation with heat recovery systems maintaining indoor air quality at 0.35 ACH. HVAC operating costs decrease proportionally to load reduction. Reduced ductwork pressurization improves system efficiency by 10-15% through lower fan energy consumption.