Heating Systems Comparison Reference
Why this matters
Customer's "I need to replace my heating" requires understanding options + climate fit + efficiency + cost. The HVAC tech who can compare options + recommend properly closes high-margin replacements. This is the field card.
Heating system types
Forced air furnace (gas/oil/electric; hot air through ducts; most common US residential). Air-source heat pump (refrigeration cycle; heats + cools; moderate climates). Geothermal/ground-source heat pump (heat from ground; premium efficiency). Boiler + hydronic (hot water to radiators OR radiant floor). Boiler + steam radiator (legacy; one-pipe/two-pipe). Radiant electric (floor/ceiling mat OR cable). Electric resistance baseboard (simple; inefficient; backup OR small space). Mini-split heat pump (ductless; zoned). Pellet stove (wood pellet; supplemental). Wood stove (traditional). Solar thermal (water; supplemental specialty). Gas fireplace + log set (supplemental).
Forced air furnace
Gas (natural/propane): most common; 80 - 98% AFUE. Oil: less common; 75 - 85% AFUE. Electric: 100% efficient but expensive operating; rare cold climates. 80% AFUE atmospheric vent (standard tier). 90 - 98% AFUE sealed combustion + condensing + PVC vent (premium). Variable-speed blower (comfort + efficiency). Modulating burner (matches firing to demand). Brands: Carrier, Trane, Lennox, Goodman, Rheem, Bryant, American Standard.
Heat pump (air-source)
Reverses refrigeration cycle: cools in summer; heats in winter.
SEER2 + HSPF2 ratings: efficiency.
Cold-climate heat pumps (Mitsubishi Hyper-Heat, Daikin, Bosch): effective to -15°F OR colder.
Auxiliary heat: gas furnace OR electric strip; below balance point.
Best for: moderate climates (40°F - 95°F outdoor); paired with backup heat in cold.
Geothermal heat pump
Earth as heat source / sink: stable 50 - 55°F year-round.
Ground loop: horizontal (large yard area) OR vertical (deep well).
Highest efficiency: COP 3 - 5 (3 - 5x energy out vs in).
Tax credit: federal 30% (2026 specifics).
Lifetime: ground loop 50+ yr; equipment 20 - 25 yr.
Boiler + hydronic
Steam boiler (legacy): rare new install; common in older urban buildings.
Hot water boiler: most common boiler today.
Distribution: radiator (cast iron OR baseboard), radiant floor, fan coil.
Efficiency: 80 - 96% AFUE typical.
Common brands: Burnham, Weil-McLain, Buderus, Triangle Tube.
Service: hydronic systems require water chemistry + annual maintenance.
Radiant floor heating
Hydronic radiant: PEX tubing in floor; water from boiler.
Electric radiant: cable OR mat under floor; controlled by thermostat.
Common location: bath, kitchen, mudroom; not whole-house typically.
Comfort: warm floor; even heating.
Electric baseboard
Resistance heating coils in baseboard.
100% efficient but expensive operating cost (electricity > gas/oil per BTU).
Best for: small additions, supplemental, where ductwork impractical.
Common in: apartments, older homes without forced-air ducting.
Mini-split heat pump
Ductless: indoor heads + outdoor compressor.
Zoned: each head independent control.
Up to 8 heads per outdoor unit (multi-zone).
Brands: Mitsubishi, Daikin, Fujitsu, LG, Bosch.
Best for: room-by-room control; additions; spaces without ductwork.
Climate considerations
Cold climate (< 20°F winter design temp):
- Gas furnace + heat pump (dual fuel)
- High-AFUE condensing furnace
- Cold-climate heat pump
- Boiler + radiant floor (commonly in retrofit)
Moderate climate (20 - 40°F):
- Heat pump primary (very efficient)
- Gas furnace OR heat pump
Hot climate (40°F+):
- Heat pump (heating rare; AC primary)
- Standard heat pump sufficient
Efficiency ratings
AFUE (Annual Fuel Utilization Efficiency): furnace + boiler.
- 80% min federal new install
- 90% high-efficiency
- 95 - 98% best-in-class condensing
HSPF2 (Heating Seasonal Performance Factor): heat pump.
- 8.8 minimum (2025+)
- 10+ premium
- 12+ best-in-class
COP (Coefficient of Performance): heat pump heat-mode.
- 2 - 3 typical air-source
- 3 - 5 geothermal
EER + SEER2 (cooling): heat pump in cooling mode.
Customer decision factors
Climate (cold = furnace OR cold-climate heat pump); energy source available (gas line, propane delivery, electricity capacity); existing equipment age (15+ yr = replacement decision); budget + financing; annual energy cost; tax credits + rebates (federal + utility); future-proofing (gas appliance bans + electrification); comfort priorities (zoned, quiet, fast warmup).
Hybrid + dual-fuel systems
Heat pump + gas furnace: heat pump runs above balance point (35 - 40°F); gas furnace below.
Thermostat controls switchover: based on outdoor temp.
Customer benefit: most-efficient operation in all temps.
Common in: cold climates with gas access.
Common heating system mistakes
Wrong sizing (Manual J load calculation; oversizing common). Wrong type for climate (heat pump only in -10°F climate = inadequate). Skipping load calculation (rule-of-thumb leads to wrong size). Skipping duct evaluation (existing ducts may be undersized for new equipment). Not coordinating with electrical (heat pump may need service upgrade). Cheap install .
Load calculation (Manual J)
Per-room heat loss calculation: required for proper equipment sizing.
Inputs: home dimensions, insulation, window U-factor + SHGC, infiltration, ductwork.
Output: BTU/hr load at design temp.
Software: Wrightsoft Right-J, Elite RHVAC.
Rule-of-thumb: 30 - 40 BTU per sq ft (varies by climate); but accurate sizing requires Manual J.
Customer education
Right-size matters: oversized = short cycles + humid + uncomfortable; undersized = can't keep up.
Maintenance is critical: annual service extends lifespan.
Air quality: humidifier + electronic filter + UV add-on.
Heat pump vs gas in cold climates: balance point concept.
Future-proofing: heat pump prepares for electrification.
References
- ACCA Manual J + Manual S + Manual D
- AHRI 210/240 (HVAC unitary equipment ratings)
- ENERGY STAR + utility rebate programs
- IECC + state energy codes
- Manufacturer technical data (Carrier, Trane, Lennox, Mitsubishi, Daikin)
- Manuall internal: Refrigerant Types, Combustion Fundamentals