1. ASHRAE Degree-Day Thermal Load Equations
Rather than relying on rough national averages, our engine models annual heating and cooling demand (in British Thermal Units, or BTUs) using each state, province, and territory's verified 30-year Heating Degree Days (HDD, Base 65°F) and Cooling Degree Days (CDD, Base 65°F):
Annual Cooling Load (BTU/yr) = Home Sq Ft × Regional CDD × 3.8 × Insulation Factor × Thermostat Setback Factor
Once annual BTU demand is established, fuel consumption and annual utility bills are derived from each system's seasonal efficiency:
Natural Gas Heating Cost ($/yr) = [ Heating BTU ÷ (100,000 BTU/therm × AFUE) ] × ($/therm)
Summer Cooling Cost ($/yr) = [ Cooling BTU ÷ (SEER2 × 1,000) ] × ($/kWh) × (1 - Solar Offset %)
2. Equipment Efficiency & Service Lifespan Benchmarks
Every HVAC comparison models both annual utility bills and expected service lifespan (including a 20-year replacement cycle):
| HVAC System Type | Heating Efficiency | Cooling Efficiency | Expected Lifespan | Default Net Install |
|---|---|---|---|---|
| Cold-Climate Heat Pump | COP 3.1 (310% Eff.) | 18.0 SEER2 | 15 Years | $6,800 |
| Ductless Mini-Split (Multi-Zone) | COP 3.4 (340% Eff.) | 21.0 SEER2 | 15 Years | $5,900 |
| Natural Gas Furnace + Central AC | 92% AFUE | 15.0 SEER2 | 18 Years | $7,500 |
| Electric Baseboard + Window AC | COP 1.0 (100% Eff.) | 10.0 SEER2 | 25 Years | $3,200 |
| Central Electric Furnace + Central AC | COP 1.0 (100% Eff.) | 14.5 SEER2 | 20 Years | $4,800 |
| Heating Oil Furnace + Central AC | 85% AFUE | 14.5 SEER2 | 18 Years | $8,200 |
| Propane Furnace + Central AC | 90% AFUE | 15.0 SEER2 | 18 Years | $7,200 |
| Geothermal Ground-Source Heat Pump | COP 4.2 (420% Eff.) | 24.0 SEER2 | 25 Years (50-Yr Loop) | $18,500 |
3. Data Sources, Editorial Policy & Contact
All 69 jurisdictions are calibrated to October 2026 residential retail electricity tariffs (US Energy Information Administration Electric Power Monthly, Hydro-Québec Tarif D, Ontario Energy Board, BC Hydro, and Alberta Utilities Commission) and NOAA / Environment Canada 30-year climate normals.
Editorial & Rate Audit Contact: Utility tariffs and federal/provincial rebate schedules are audited quarterly. To report a local utility tariff update or request a custom municipal dataset, contact our engineering research desk at research@findmyheatbill.com. Browse all regional guides in our US State Directory, Canada Provincial Directory, or 2026 Data Studies Hub →