Apex Heat Pump vs Gas Furnace and Dual-Fuel Costs

When an Apex furnace or heat pump reaches the end of its life, the usual question is which fuel to heat with: an all-electric heat pump, a gas furnace with central air, or a dual-fuel system that pairs a heat pump with a gas furnace and switches between them. The right answer depends on your local energy prices, so this guide starts with who actually supplies energy in Apex and then works through the operating cost math with the current published rates.

First, who supplies your electricity and gas?

A common assumption is that Apex homes buy electricity from Duke Energy and gas from Dominion Energy. Neither is quite right. The Town of Apex describes itself as a public power community that provides electric service to more than 32,000 residential and commercial customers, and its infrastructure page names PSNC Energy as the natural gas provider (Town of Apex, Infrastructure). PSNC (Public Service Company of North Carolina) now does business as Enbridge Gas North Carolina, and its rate summary is published under that name. Some addresses with an Apex mailing address sit outside the town limits and may be served by Duke Energy Progress (Duke Energy Progress residential schedule RES) or another provider. Check the name on your electric bill before running any numbers.

The current rates

The Town of Apex residential electric schedule, effective July 1, 2026, has a $29.75 monthly customer charge and an energy charge of $0.12520 per kWh for all usage, plus 7% North Carolina sales tax (Town of Apex Residential Electric Rate Schedule; all schedules are listed on the Town rates page).

Enbridge Gas North Carolina's rate summary effective October 1, 2026 lists residential Rate 101 (Residential Service) at a $12.00 monthly facilities charge, $1.49496 per therm November through April and $1.41175 per therm May through October (Enbridge Gas NC current rate summary). Rate 102 (High-Efficiency Residential Service) is lower per therm ($1.42446 winter, $1.34125 summer); check the tariff for which rate applies to your account.

Break-even math: when is a heat pump cheaper than gas?

One million BTU (MMBtu) of heat equals about 293 kWh of electricity or 10 therms of gas. Using the rates above (before sales tax and fixed charges):

• Electric resistance heat (COP 1.0): 293 kWh x $0.1252 = about $36.69 per MMBtu delivered.
• Heat pump at COP 2.0: about $18.35 per MMBtu. At COP 3.0: about $12.23.
• Gas furnace, 95% AFUE: 10 therms x $1.49496 / 0.95 = about $15.74 per MMBtu. At 80% AFUE: about $18.69.

Dividing the resistance cost by the furnace cost gives the break-even coefficient of performance: about 2.3 against a 95% furnace and about 2.0 against an 80% furnace. When the heat pump is running above that COP, it heats more cheaply than gas at these rates; below it, gas is cheaper per unit of heat. These figures leave out the $12 gas facilities charge, which you pay every month you keep gas service, and an all-electric home avoids it entirely.

A heat pump's COP falls as the outdoor temperature drops, and the exact curve differs by model. Ask for the manufacturer's extended performance data, which lists capacity and COP at each outdoor temperature, so you can see where your specific unit crosses the break-even COP.

Balance points: thermal and economic

Two different balance points matter in dual-fuel design. The thermal balance point is the outdoor temperature at which the heat pump's capacity just equals the home's heat loss; below it, the heat pump cannot keep up alone. The economic balance point is the temperature at which the heat pump's COP falls to the break-even figure above. A dual-fuel thermostat or control is typically set to switch to gas at whichever of the two is higher. Because the economic balance point moves with energy prices, it is worth revisiting when Enbridge or the Town changes rates.

Sizing a dual-fuel system

• Start with a load calculation. A room-by-room heat loss and heat gain calculation (Manual J) sets the cooling size, which usually governs the heat pump in central North Carolina.
• Size the furnace for the full heating load. In a dual-fuel system the furnace carries the coldest hours by itself.
• Match the coil and the furnace blower. The heat pump's indoor coil sits on the furnace, so airflow has to suit both.
• Program the lockout. Set the switchover temperature from the economic balance point instead of using a default.
• Keep the permits in order. Equipment replacement requires a mechanical permit; see our Apex mechanical permit guide.

Which option fits which house?

A home without existing gas service carries the cost of a new gas line plus the monthly facilities charge, which tilts the math toward an all-electric heat pump. A home already on Enbridge gas with a sound flue and furnace location is the natural candidate for dual fuel. Either way, run the numbers with the rates printed on your own bills, since rates and riders change. For background on how dual fuel works, see dual-fuel HVAC systems in Apex.

Sources: Angi, heat pump cost; Angi, new furnace cost. Ranges are attributed to the publisher named; they are national or regional estimates compiled by that publisher, not quotes and not prices from any provider on this site.

Local rules and code references

• Town of Apex, Infrastructure: Town public power electric service; PSNC Energy natural gas.
• Town of Apex, Residential Electric Rate Schedule (eff. July 1, 2026): $29.75 customer charge; $0.12520/kWh.
• Enbridge Gas North Carolina, current rate summary (eff. Oct 1, 2026): Rate 101 and 102 facilities and per-therm charges.
• Duke Energy Progress, Residential Service Schedule RES: for addresses outside Town electric territory.

Code text, policy forms and department procedures change. Confirm current requirements with the jurisdiction, your insurer or the utility before work starts.