Natural Gas vs. Propane vs. Heat Pumps: Which Is Cheapest to Heat Your Home in Missouri?

As the temps start to dip here in Missouri, a lot of homeowners start wondering the same thing:
What’s the cheapest way to heat my home this winter?

We ran the numbers for a “typical Missouri home” with average insulation and air leakage and compared four common heating options — plus two modern heat pumps — across outdoor temperatures from 10°F up to 60°F.

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The Contenders

Here’s what we compared:

1. 80% Efficient Natural Gas Furnace

2. 95% Efficient Natural Gas Furnace

3. 80% Efficient Propane (LP) Furnace

4. 95% Efficient Propane (LP) Furnace

5. 14.3 SEER2 Heat Pump

6. Cold Climate 19 SEER2 Heat Pump

We used Missouri’s average energy prices (as of late 2025):

• Electricity: 12.9¢ per kWh

• Natural Gas: $15.65 per Mcf (≈ $0.015 per cu ft)

• Propane (LP): $2.04 per gallon

All systems were modeled heating a standard home held at 68°F indoors, assuming normal heat loss for our climate and building stock.

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What We Found

At each outdoor temperature (10°, 20°, 30°, 40°, 50°, 60°F), we calculated the cost to produce the necessary heat per hour. Here’s what stood out:

🔹 Propane Is the Most Expensive Fuel

Even with a high-efficiency 95% furnace, propane heating costs roughly 1.8–2× more per hour than natural gas at the same temperature.
That’s because propane costs more per unit of energy — even though it burns hotter, it’s still not enough to offset the price difference.

🔹 Natural Gas Furnaces Stay Steady

Between 80% and 95% efficiency, the 95% AFUE furnace saves around 15–20% in operating cost — not huge per hour, but it adds up quickly over a season.

🔹 Heat Pumps Dominate at Milder Temps

When outdoor temps are 40°F and above, both heat pumps outperform even the best gas furnace.

• The 14.3 SEER2 model is great for moderate climates.

• The cold-climate 19 SEER2 unit shines in the 10–30°F range, maintaining a high COP (Coefficient of Performance), meaning it produces multiple units of heat for every unit of electricity consumed.

At 50–60°F, the heat pumps are by far the cheapest to run.

🔹 Cold Weather Shift Point

Below about 20°F, traditional (non-cold-climate) heat pumps start to lose efficiency, while furnaces hold steady.
That’s where dual-fuel systems — a heat pump paired with a gas furnace — deliver the best of both worlds.

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The Results at a Glance

System Type	Typical Cost per Hour @ 30°F	Fuel Type
80% Gas Furnace	≈ $0.55/hr	Natural Gas
95% Gas Furnace	≈ $0.46/hr	Natural Gas
80% LP Furnace	≈ $1.02/hr	Propane
95% LP Furnace	≈ $0.86/hr	Propane
14.3 SEER2 Heat Pump	≈ $0.38/hr	Electric
19 SEER2 Cold Climate	≈ $0.30/hr	Electric

(Based on modeled data for a typical Missouri home — actual results vary with house size and insulation.)

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What This Means for Homeowners

If your home is on natural gas, upgrading from an 80% to a 95% furnace can save real money each season — but if you’re using propane, a cold-climate heat pump may actually be cheaper to run, even in the 20s.

Modern heat pumps aren’t what they used to be — today’s units deliver serious performance, even in freezing weather.
And for homes in rural areas without access to natural gas, they’re becoming the go-to solution for both comfort and cost savings.

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Bottom Line

• Best overall value: Cold-climate 19 SEER2 Heat Pump

• Best for very cold temps or older homes: 95% AFUE Natural Gas Furnace

• Most expensive fuel: Propane (LP), even at high efficiency

If you’d like to find out how much you could save with a new high-efficiency system, Aire Solutions can run a custom analysis for your home — factoring in your fuel type, insulation, and local energy prices.

👉 Call Aire Solutions at (573) 335-2665 or visit airesolutionscape.com to schedule your free consultation.