Calculate required BTU capacity for a single-zone heat pump installation.

This tool performs a quick sizing calculation based on:

• Home location (ZIP code) for climate zone and design temperature

• Square footage and building age for heat loss estimation

• Optional humidity considerations for enhanced dehumidification needs

Returns: Dictionary with: - required_btu: Recommended BTU capacity - btu_range_min/max: Acceptable range for equipment selection - design_temperature: Design heating temperature for location - climate_zone: ASHRAE climate zone - recommended_models: List of suitable heat pump models - calculation_notes: Detailed explanation of calculations - humidity_recommendations: Optional humidity control advice - oversizing_warnings: Warnings if system may be oversized

Calculate heating/cooling loads for a multi-zone home with detailed zone-by-zone analysis.

Each zone should specify:

• name: User-defined zone name

• square_feet: Zone area (50-5000 sqft)

• ceiling_height: Height in feet (7-20 ft, default 8)

• zone_type: living_area, bedrooms, kitchen, basement, attic, garage, other

• sun_exposure: north, south, east, west, minimal

• window_coverage: Percentage of wall area as windows (0.0-0.5, default 0.15)

• occupancy: high, medium, low

• heat_sources: List like ["kitchen_appliances", "electronics", "home_office"]

• air_sealing: tight, average, leaky

• is_above_grade: True if above ground level

Returns: Dictionary with: - total_cooling_load/total_heating_load: Total BTU requirements - zone_results: Detailed results for each zone - system_options: Recommended multi-zone configurations - climate_info: Location-specific climate data - recommendations: Installation and design recommendations

Estimate annual electricity costs and payback period for heat pump vs current heating system.

Analyzes:

• Monthly heating load based on location and home characteristics

• Heat pump electricity consumption using model's efficiency (HSPF2)

• Comparison with current heating fuel costs

• 10-year cost projection with savings analysis

• Break-even year calculation

Returns: Dictionary with: - location_info: Climate and location details - electricity_rate: Rate used for calculations ($/kWh) - gas_rate: Comparison fuel rate if applicable - heat_pump_info: Selected model specifications - monthly_breakdown: Month-by-month cost comparison - annual_summary: Annual totals and payback analysis - ten_year_projection: Long-term savings projection - calculation_notes: Important assumptions and notes

Verify heat pump performance at design temperature and determine backup heat requirements.

Analyzes:

• Heat pump capacity at design temperature (coldest expected outdoor temp)

• Percentage of heating load covered by heat pump alone

• Required backup heat capacity to cover shortfall

• Temperature range where heat pump provides full heating

• COP (efficiency) across temperature range

Critical for cold-climate installations to ensure adequate heating on coldest days.

Returns: Dictionary with: - location_info: Climate zone and design conditions - heat_pump_model: Selected model name - capacity_curve: Heat pump capacity at various outdoor temperatures - performance_analysis: Coverage at design temp, backup heat needed - backup_heat_recommendation: Recommended backup system if needed - temperature_range_analysis: Performance across temperature ranges - key_findings: Important observations - warnings: Critical issues or limitations

Get the current electricity rate for a specific ZIP code location.

Fetches residential electricity rates from EIA (Energy Information Administration) API. Requires EIA_API_KEY environment variable to be set.

Returns: Dictionary with: - zip_code: Input ZIP code - electricity_rate: Rate in $/kWh - unit: Always "$/kWh" - source: Data source information

List available heat pump models, optionally filtered by brand, capacity, or efficiency.

Returns comprehensive database of heat pump models with:

• Brand and model name

• BTU capacity (heating/cooling)

• HSPF2 efficiency rating (higher is more efficient)

• Estimated price range

Filters:

• brand: Case-insensitive partial match (e.g., "Mitsubishi", "Fujitsu")

• min_btu/max_btu: Capacity range for sizing

• min_hspf2: Minimum efficiency threshold (typical range: 8.0-12.0)

Returns: Dictionary with: - total_models: Count of models matching filters - brands: List of available brands - models: List of model details