Practical guide to choosing between gas-fired and electric furnaces for small aluminium foundries. Compare energy costs, melt loss, and control. Based on 25 years of experience.
For a small foundry, the choice between gas-fired and electric furnaces comes down to six factors: energy cost per tonne, metal melt loss, temperature control, melt rate, maintenance, and local utility availability. There is no universal winner. The right choice depends on where you are, what you melt, and how you operate.
I've helped small foundries choose furnaces across Southeast Asia, India, the UK, and Europe. The decision is rarely about the furnace itself. It's about the economics of your specific location.
The Six Factors That Actually Decide It
| Factor | Gas-Fired | Electric (Resistance/Induction) |
|---|---|---|
| Energy cost per tonne | Lower in most gas-producing regions | Lower where electricity is cheap or subsidised |
| Metal melt loss | Typically 2–3% | Typically 0.5–1.5% |
| Temperature control | ±10–15°C | ±5°C or better |
| Melt rate | Faster for cold charging | Slower cold start, excellent for holding |
| Maintenance | Burner, refractory, flue | Heating elements, crucible, electrical |
| Utilities required | Gas supply, ventilation, flue | High-capacity electrical connection |
Let's go through each one.
Energy Cost: Where Gas Wins and Where It Doesn't
This is the single biggest variable. And it swings wildly depending on where you are.
In Southeast Asia and India, industrial natural gas is often cheap. A foundry in Vietnam or Thailand can melt aluminium for a fraction of the cost of electricity. One operator in Vietnam reported that switching to two 2.5-tonne gas furnaces cut energy costs by over 260 RMB per tonne compared to their electric furnaces. Melt time also dropped from 1 hour 40 minutes to 1 hour 20 minutes.-
In Europe, the picture is different. Electricity prices in 2026 sit in the €80–€120/MWh range for industrial users.- But gas prices are also volatile. The EU's CBAM (Carbon Border Adjustment Mechanism) now covers aluminium products, and the emissions from your melting furnace directly affect your export competitiveness.
The practical rule: Calculate your local energy cost per tonne, not per kWh or per m³. Use actual delivered prices. Then compare.
Here's a simple calculation I use with clients:
Electric: Tonne consumption × electricity price per kWh = cost per tonne
Gas: Tonne consumption × gas price per m³ = cost per tonne
For a small foundry melting 2 tonnes per day, a 20% difference in energy cost per tonne is roughly $4,000–$8,000 per year. That's significant. But it's not the only number.
Metal Melt Loss: The Hidden Cost Nobody Talks About
Gas-fired furnaces typically lose 2–3% of metal as oxidation and dross.- Electric furnaces, especially induction and resistance, lose 0.5–1.5%.
On a foundry melting 2 tonnes per day, that 1.5% difference equals 30 kg of aluminium lost every day. At $2,500 per tonne, that's $75 per day. Over a year, nearly $19,000.
I've seen this first-hand. A die casting plant in Malaysia ran a gas-fired reverberatory furnace at 770°C. Oxidation loss was 4.5%. We lowered the temperature to 735°C and added a cover flux. Loss dropped to 1.8%. The annual saving in metal alone was over $45,000.
If you melt high-value alloys or aerospace-grade aluminium, the metal loss advantage of electric furnaces often outweighs the energy cost difference.
Temperature Control and Melt Quality
Electric furnaces win here. Hands down.
An electric resistance or induction furnace can hold temperature within ±5°C. A gas-fired crucible furnace typically holds ±10–15°C, and that's with a good control system. Without one, it's worse.
Why does it matter? Aluminium alloy chemistry is sensitive to temperature. Run too hot, and you increase oxidation and hydrogen absorption. Run too cold, and you get incomplete melting and cold shuts.
I've seen foundries struggle with inconsistent casting quality because their gas furnace temperature swung by 20°C across the bath. Switching to an electric holding furnace solved the problem. The metal quality became consistent, and the rejection rate dropped.
For small foundries doing precision work, or casting thin-wall parts, electric furnaces are usually the better choice for temperature control.
Melt Rate and Production Schedule
Gas furnaces melt faster from cold. If you're starting up every morning and melting from solid, gas has the advantage. The flame delivers high heat directly to the charge.
Electric resistance furnaces are slower to cold-start. But they excel at holding temperature. Induction furnaces are fast, but the infrastructure cost is higher.
For a small foundry operating one shift per day, gas is often more practical. For a foundry running continuous or multi-shift operations, electric holding furnaces paired with a gas melter can be the best of both worlds.
I know a jobbing foundry in the UK that runs a small gas-fired crucible furnace for melting and an electric resistance holding furnace for pouring. They melt fast with gas, then hold precisely with electricity. The combination costs less than a single large electric melter.
Maintenance and Spare Parts
Gas furnaces need burner maintenance, refractory repair, and flue cleaning. Electric furnaces need heating element replacement, crucible inspection, and electrical checks.
Which is easier depends on your team. If you have a maintenance engineer comfortable with gas trains and combustion, gas is fine. If your team is more electrical, electric may be simpler.
But here's the thing: spare parts availability matters more than maintenance type. A gas burner nozzle is usually cheap and available locally. A specialised electric heating element may need to be imported, with lead times of weeks.
I always ask suppliers: "If this part fails, how fast can you get me a replacement?" If the answer is vague, that's a red flag.
A Real Case from India
In 2024, a small jobbing foundry in Coimbatore, India, was deciding between a gas-fired crucible furnace and an electric resistance furnace. They melted 800 kg per day of LM6 and LM25 alloys.
Their energy costs:
- Gas: ₹32 per kg of aluminium melted
- Electric: ₹38 per kg of aluminium melted
Gas was cheaper. But their metal loss with gas was 2.8%. With electric, it would be 1.2%. The metal saved offset the higher energy cost almost exactly.
They chose electric. Why? Because their castings were thin-wall and required tight temperature control. The gas furnace couldn't hold ±5°C. The electric furnace could.
Two years later, their rejection rate had dropped from 6% to 2.5%. The energy cost premium was more than covered by better yield.
A Simple Decision Framework
Ask yourself these questions in order:
What is your actual energy cost per tonne? Calculate it. Don't guess.
How much metal do you lose to oxidation? If it's above 2%, electric may pay for itself.
How tight does your temperature need to be? If ±5°C matters, go electric.
What utilities do you have? Gas line or high-capacity electrical supply?
What is your production schedule? One shift? Multi-shift? Continuous?
Can you get spare parts locally? This often decides it.
If gas is cheap and you melt bulk aluminium for general castings, gas wins.
If electricity is affordable and you need precise temperature or low metal loss, electric wins.
If you have both, consider a hybrid: gas for melting, electric for holding.
Final Thoughts
The gas vs electric decision is not about technology. It's about your local economics and your quality requirements.
In Southeast Asia and India, gas is often the practical choice for small foundries melting bulk aluminium. In Europe and the UK, electricity prices are high, but metal loss and emissions regulations are pushing more foundries toward electric.
I've seen both work. I've also seen both fail. The difference is never the furnace. It's whether the foundry did the math before they bought it.
Do the math. Then decide.
Internal links: How to Choose the Right Aluminium Melting Furnace, How to Optimize Burner Efficiency in Gas-Fired Aluminium Furnaces, Furnace Maintenance Checklist.
About the Author: Hu Shenyue is a veteran aluminium melting furnace expert with 25 years of hands-on experience in China, Southeast Asia, India, the UK, and Europe. He writes practical, experience-based content on furnace selection, maintenance, and optimisation at SmeltPro.
