All Climate Zones
Zone 1-2
Hot-Humid Climate Windows
Window selection guide for IECC Climate Zones 1-2: Hot-humid climates including Florida, South Texas, Hawaii, and southern coastal regions.
Energy Code Requirement
U-0.50 (insulation less critical)
U-Factor Maximum
Solar Heat Gain
SHGC ≤0.25 (REQUIRED - blocks solar heat)
SHGC Requirement
Heating Degree Days
0-2,000 annually
Annual Average
Climate Zone Zone 1-2 Characteristics
Temperature & Climate
- Climate Type
- Hot-Humid (Tropical/Subtropical)
- Average Summer
- 85-95°F (29-35°C)
- Average Winter
- 50-70°F (10-21°C)
- Cooling Degree Days
- 3,000-5,000+ annually
Energy Priorities
- Primary Concern
- Cooling costs and solar heat gain
- Secondary Concern
- High humidity and moisture management
Specific Challenges for Hot-Humid Climates
- ▸Extreme solar heat gain drives AC costs 70-80% of energy bill
- ▸Year-round high humidity increases condensation risk
- ▸Salt air corrosion near coast damages frames and hardware
- ▸UV exposure degrades seals and coatings rapidly
- ▸Hurricane/storm resistance requirements in coastal areas
- ▸Minimal heating needs (focus entirely on cooling efficiency)
Energy Code Requirements
- Energy Code
- IECC 2018/2021 Climate Zone 1-2
- Air Leakage Maximum
- ≤0.3 cfm/ft²
- Additional Notes
- SHGC is critical requirement. Impact-resistant glazing required in hurricane zones. Focus on solar control, not insulation.
Recommended Window Configurations
Standard Solar Control
Budget- Pane Count
- Double-pane
- Low-E Coating
- Low-E3 (solar control)
- Gas Fill
- Air or argon
- Frame Material
- Vinyl or aluminum
- U-Factor
- U-0.35 to U-0.40
- SHGC
- SHGC 0.20 to 0.25
- Cost Range
- $400-$650 per window
- Payback Period
- 4-6 years from reduced AC costs
High-Performance Solar Control
Premium- Pane Count
- Double-pane with advanced coating
- Low-E Coating
- Low-E3 or spectrally selective
- Gas Fill
- Argon fill
- Frame Material
- Vinyl (corrosion-resistant) or fiberglass
- U-Factor
- U-0.28 to U-0.32
- SHGC
- SHGC 0.18 to 0.22
- Cost Range
- $550-$900 per window
- Payback Period
- 5-7 years, dramatic AC cost reduction
Common Window Problems in Hot-Humid Climates
- Solar heat gain overwhelming AC systems - SHGC ≤0.25 essential
- High humidity causing condensation between panes
- Salt air and UV exposure degrading seals (coastal areas)
- Hurricane/impact resistance requirements increasing costs
- Mold and mildew growth around frames from humidity
- Year-round UV exposure shortening seal lifespan to 12-18 years
Energy Cost Analysis
Annual Heating
$200-$400 (minimal)
Annual Cooling
$2,000-$3,500 (major expense)
Potential Savings
$400-$700/year with SHGC ≤0.22 windows
Utility Rate
$0.12-$0.16/kWh (varies by state)
Recommended Window Products
Andersen
400 Series with SmartSun glass
SHGC 0.21, U-0.30, Impact-rated available
Pella
250 Series with AdvancedLow-E
SHGC 0.23, U-0.28, Hurricane-rated
Milgard
Tuscany Series with SunCoat
SHGC 0.19, U-0.29, Coastal warranty
Note: Product availability and specifications may vary. Always verify current specs with manufacturers and local dealers.