Quick answer
Read in 4 minIf you have natural gas, a 96% AFUE furnace + AC is still the lowest-stress option for SW Indiana winters that bottom out at -12°F. A heat pump alone struggles below 25°F without electric strip backup that erases its savings. The sweet spot for most Ohio Valley homes with gas service is dual-fuel: a heat pump for mild days, a gas furnace as backup for the polar-vortex week.
- 01 Gas furnace + AC: lowest operating cost in SW Indiana if you have natural gas.
- 02 Heat pump alone: works great down to ~25-30°F, then needs expensive electric strip backup.
- 03 Dual-fuel (heat pump + gas furnace): best of both — uses heat pump above 32°F, furnace below.
- 04 All-electric heat pump: right call only if you have no gas line or electricity is your only option.
- 05 Coldest SW Indiana day in last 10 years: -12°F. Plan backup heat for that day, not the average.
Section 02
Replacing both heating and cooling at once
Both your furnace and AC are tired and you're deciding what to put in. This is the rare moment when heat pump vs furnace is genuinely an open question — replacing only the AC and keeping a working furnace usually settles it the other way.
Section 03
Comparing operating costs at SW Indiana rates
At current Vectren gas ($0.85-$1.10/therm) and Duke/CenterPoint electric ($0.12-$0.15/kWh) rates, gas heat costs roughly $1.00 per 100,000 BTU; heat pump heat at COP 3.5 costs roughly $1.05; heat pump heat on electric strips costs $3.40. That last number is the catch — when the heat pump drops to strip mode in January, your bill triples.
Section 04
Planning for the -12°F day
Polar vortex events are getting more common — we've seen at least 3 in the last decade. A heat pump rated to 17°F is great 350 days a year, but you have to plan for the 10 days it can't keep up. Dual-fuel does that with cheap gas; all-electric does it with expensive strips. Pick your backup before you pick the heat pump.
Section 05
When natural gas isn't an option
If your home is on propane or has no gas line at all, the math shifts. Propane heat at $2.50-$3.00/gallon often costs more than heat pump heat in shoulder seasons, which makes an all-electric or dual-fuel heat pump with propane backup competitive. Rural homes outside Haubstadt and Vincennes are often in this category.
Compare your options
The choice, honestly compared.
Option A: 96% AFUE gas furnace + standard AC
Right call when you have natural gas service and want the simplest, most predictable setup. A Trane S9V2 + matched AC runs roughly $9,500-$13,500 installed depending on tonnage. Lowest operating cost in our climate, biggest installed base means easiest service, no learning curve on thermostats. Wrong call if you're paying high gas hookup fees or your home is all-electric. Lifespan: 15-20 years for the furnace, 12-15 for the AC.
Option B: Dual-fuel (heat pump + gas furnace)
Right call for most SW Indiana homeowners who have natural gas and want lower shoulder-season bills. A Carrier Infinity 19VS heat pump paired with a 96% AFUE furnace runs roughly $13,500-$18,000 installed. Heat pump handles October-November and March-April at COP 3.0+; furnace takes over below ~32°F. Lowest overall operating cost, comfort and resilience of gas backup. Wrong call if your AC is brand new (no reason to swap it for a heat pump). Lifespan 15-20 years.
Option C: All-electric cold-climate heat pump
Right call when you have no gas line, want to fully electrify, or are pairing with solar. A Mitsubishi Hyper-Heat or Lennox SL25XPV cold-climate heat pump runs roughly $14,000-$20,000 installed and rates down to about 5°F before strip heat kicks in. Quiet, efficient most of the year, no combustion or CO concerns. Wrong call when you have $0.85/therm gas — strip heat days will spike your January bill noticeably. Lifespan 15-20 years.
Key terms in context
Vocabulary you'll see on a real estimate.
This guide is written for heating & cooling decisions in Southwest Indiana. It uses the same terminology you'll hear from techs, inspectors, and the permit office.
Failure mode 01
Going all-electric on a home with cheap gas
If your gas bill is $80/month in January now, an all-electric heat pump can spike to $300+ during a cold snap when strip heat carries the load. We've seen this catch homeowners off-guard — the equipment works fine, the bill is the surprise.
Failure mode 02
Undersizing the heat pump backup
A dual-fuel system needs the gas furnace sized for the full design load, not just supplemental — when the heat pump locks out at -5°F, the furnace has to carry everything. Skimping here means a cold house at the worst possible moment.
Proof, process & local validation
- 01 Operating cost comparisons use your zip code's actual utility rates, not regional averages.
- 02 Heat pump changeover temps are set during commissioning based on your home's load curve and utility rates.
- 03 Pat installs dual-fuel in his own home and his daughter's — same equipment we recommend to you.
How we build this guidance
- We've installed dual-fuel systems across SW Indiana since 2009 — we know the changeover temps that work in the Ohio Valley specifically.
- Pat won't recommend an all-electric heat pump for a home with $0.40/therm gas service unless it pencils out — and it usually doesn't here.
- EPA-certified — we install Trane, Carrier, and Lennox equipment, and we recommend what works, not what gets us the biggest spiff.
Methodology · Equipment selection follows Manual J load, Manual S sizing, and your zip code's published utility rates. We document the changeover temperature math.
Last updated 2026-06-24
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Common questions
Questions, answered.
01 Will a heat pump keep up at -10°F in Indiana?
A standard heat pump rated to 17°F will need electric strip backup below about 25°F, and at -10°F it's running mostly on strips — which costs roughly 3x gas heat. Cold-climate heat pumps (Mitsubishi Hyper-Heat, Lennox SL25XPV) maintain capacity down to about 5°F before strips engage. Either way, you need a backup plan for the polar-vortex days we get every few years.
02 Is dual-fuel really cheaper than gas alone?
Usually yes by 10-20% over a heating season at current rates. The heat pump runs on cheap electricity during October, November, March, and April — when gas heat is overkill. Below about 32°F the gas furnace takes over. The upgrade cost is recovered in 7-10 years on operating savings, plus you get the heat pump as your AC.
03 Do I need to keep my old gas furnace?
Not unless it's young and healthy. Most dual-fuel installs include a new high-efficiency furnace as the backup so the whole system is matched and warrantied together. Keeping an aging furnace as backup means the next breakdown is a furnace breakdown — you haven't reset anything.
04 Are heat pumps eligible for the 25C federal tax credit?
Yes — qualifying heat pumps get up to $2,000 in federal tax credit under 25C through 2032 (current law). Some utility rebates stack on top. We file the paperwork and document the model numbers needed for the credit.
05 How loud is a heat pump compared to an AC?
Modern variable-speed heat pumps run 55-65 dB outdoors — similar to or quieter than a standard AC. Cold-climate units are often quieter because they modulate. The defrost cycle (about every 90 minutes in winter) makes a soft whoosh you'll notice the first time and then ignore.
