When buying a ducted central heater, consider heating capacity, energy efficiency, installation type, size, noise levels, and warranty options for optimal performance.
Choosing the right ducted central heater requires careful consideration of several technical and practical factors. From BTU output to energy efficiency ratings, the right system can save you thousands on energy bills while keeping your home comfortable year-round.
Heating Capacity (BTU Output)
British Thermal Units (BTUs) measure heating power. An undersized unit won’t heat properly, while an oversized one cycles too frequently.
How to Calculate Your Needs
Use this formula: (Square footage × 20) + (Number of windows × 1,000) + (Number of exterior doors × 2,000). For example:
| Home Size | Recommended BTU |
|---|---|
| 1,000 sq ft | 30,000-45,000 BTU |
| 2,000 sq ft | 60,000-90,000 BTU |
Energy Efficiency (AFUE Rating)
Annual Fuel Utilization Efficiency measures what percentage of fuel converts to heat. Higher AFUE means lower operating costs.
Current Standards
- Minimum: 80% AFUE
- High-efficiency: 90-98.5% AFUE
For maximum efficiency, consider pairing with a smart thermostat to optimize performance.
Fuel Type Considerations
Natural Gas
Most common, requires gas line. Look for models with electronic ignition instead of standing pilot lights.
Electric
Easier installation but higher operating costs in many areas. Ideal for homes without gas access.
Propane
Good alternative where natural gas isn’t available. Requires tank storage. See our guide on indoor propane heaters for supplemental options.
System Components
Heat Exchanger
Stainless steel models last longer than aluminized steel. Look for lifetime warranties on this critical component.
Blower Motor
- Standard: Single-speed
- Better: Multi-speed
- Best: Variable-speed (ECM)
Ignition System
Hot surface ignition is more reliable than spark ignition. For replacement parts, check our igniter guide.
Installation Requirements
Proper installation affects performance and safety. Key factors:
- Ductwork compatibility (size and condition)
- Venting requirements (direct vent vs power vent)
- Electrical needs (voltage and amperage)
- Clearance from combustible materials
Advanced Features
Modulating vs Staged Heating
Modulating units adjust output in 1% increments for precise temperature control. Staged units (typically 2-3 stages) offer partial modulation.
Smart Connectivity
Wi-Fi enabled systems allow remote monitoring and control via smartphone apps.
Zoning Compatibility
Works with dampers to heat different areas independently. Can reduce energy use by 20-30%.
Warranty Coverage
Typical coverage periods:
- Heat exchanger: 20 years to lifetime
- Parts: 5-10 years
- Labor: 1-5 years
According to ENERGY STAR, proper maintenance can extend system life by 5-10 years.
Operating Costs
Calculate annual costs with this formula: (BTU output ÷ AFUE) × (Hours used/year) × (Fuel cost per BTU). Example for a 100,000 BTU unit:
| AFUE | Annual Gas Cost* |
|---|---|
| 80% | $1,250 |
| 96% | $1,042 |
*Based on 1,500 heating hours and $1.00/therm natural gas
Rebates and Tax Credits
The federal tax credit covers 30% of qualifying system costs up to $2,000. Many utilities offer additional rebates for high-efficiency installations.
