Most Minnesota homes in the Twin Cities metro use natural gas for heating. But if you live in a rural area without gas service, propane is your primary fuel option. Understanding the differences helps you make smarter buying decisions.
The Key Differences
Fuel Delivery and Cost
Natural gas arrives via pipeline from your utility. Propane is delivered by truck to a tank on your property. Natural gas in Minnesota averages $1.00-$1.30 per therm (100,000 BTU). Propane averages $2.00-$3.50 per gallon (91,500 BTU). Per BTU, propane costs 2-3 times more than natural gas. For a typical Minnesota home, that means $800-$1,040 annually on gas versus $1,760-$3,040 on propane.
Equipment Differences
Natural gas and propane furnaces are the same furnace with different gas orifices. The heat exchanger, blower, control board, and cabinet are identical. Propane burns hotter and requires smaller orifices to deliver correct BTU output. Most furnaces ship configured for natural gas with propane conversion kits available.
Conversion Kits
A propane conversion kit includes smaller orifices and gas valve pressure adjustments. On Goodman furnaces, LP conversion takes about 30 minutes for a competent technician. Getting conversion right is critical — running propane through natural gas orifices produces dangerously high BTU output, oversized flames, and carbon monoxide risk.
Efficiency Matters More with Propane
AFUE ratings apply equally to both fuels. But because propane costs more per BTU, high efficiency saves more dollars. Upgrading from 80% to 96% AFUE on a $2,500 annual propane bill saves approximately $420 per year — the upgrade pays for itself faster than with natural gas.
Propane Tank Ownership
Owned tanks let you shop for cheapest propane from any supplier. Leased tanks lock you into one company at premium prices. Buying your own tank ($800-$2,500) often pays for itself in 2-3 years through lower fuel costs.
Should You Switch Fuels?
If natural gas is available at your property, switching from propane almost always makes sense despite the $2,000-$5,000 connection cost. Annual savings of $960-$2,000 mean payback in 2-4 years. If staying on propane, invest in the highest-efficiency furnace available to maximize fuel savings.
At Furnace Direct, we sell Goodman furnaces for both natural gas and propane installations at factory-direct pricing. Same-day delivery to the Twin Cities metro on orders before 3 PM CT, and we ship throughout Minnesota for rural propane customers.
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