How accurate is this furnace savings calculator?

The calculator uses standard AFUE (Annual Fuel Utilization Efficiency) math to estimate savings based on the percentage of gas your furnace actually converts to heat. The math is reliable. Actual savings depend on Detroit gas prices, your home's insulation, weather variability, and how often you run the furnace. For an exact savings estimate based on your specific home, we provide free in-home assessments at (313) 398-0504.

What is AFUE and why does it matter?

AFUE (Annual Fuel Utilization Efficiency) measures how much of your gas actually becomes heat versus going up the flue. An 80% AFUE furnace turns 80 cents of every gas dollar into heat - the other 20 cents is wasted. A 97% AFUE furnace wastes only 3 cents per dollar. For typical Detroit homes spending $1,200-$2,400 per heating season on gas, upgrading from 80% to 96% AFUE saves roughly $200-$400 per year - $3,000-$6,000 over a 15-year furnace lifespan.

What DTE rebates are available for new furnaces in Detroit?

DTE Energy offers furnace rebates based on AFUE efficiency rating: $150 rebate for 92-94% AFUE furnaces, $300 rebate for 95-96% AFUE furnaces, and $500 rebate for 97%+ AFUE furnaces. The furnace must be ENERGY STAR certified and properly registered. Big Mike's handles the DTE rebate paperwork at no charge with every install. Consumers Energy customers get similar rebates through their efficiency programs.

What is the federal 25C tax credit?

The federal 25C Energy Efficient Home Improvement Credit covers up to $600 on qualifying gas furnaces with 97%+ AFUE rating. For heat pumps the credit jumps to $2,000. It's claimed when you file taxes - we provide the AHRI matching documentation required at no charge. Combined with DTE's $500 rebate on the same units, you can get up to $1,100 back on a high-efficiency furnace installation.

Is upgrading from an old furnace really worth it?

For most Detroit homes with 15+ year old furnaces, yes - the math usually works. Older 65-80% AFUE furnaces waste 20-35% of your gas. A modern 95% AFUE upgrade typically pays for itself in 7-12 years through gas savings alone, with DTE rebates ($150-$500) and the federal 25C tax credit (up to $600) shortening the payback by another 1-2 years. Plus newer furnaces last longer, are quieter, and break down less - reducing repair costs over the next decade.

What's a typical Detroit heating bill?

Detroit metro heating bills vary based on home size, insulation, and furnace efficiency, but typical ranges are: small home (under 1,500 sqft): $900-$1,400/year. Average home (1,500-2,500 sqft): $1,400-$2,200/year. Larger home (2,500-3,500 sqft): $2,200-$3,200/year. Older homes with poor insulation often pay 30-50% more than these averages. To use this calculator, add up your gas bills from November through March - or use $1,800 as a Detroit average if you're unsure.

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FREE TOOL · INSTANT SAVINGS ESTIMATE

Energy Savings Calculator

Find out exactly how much you’d save by upgrading your old furnace to a high-efficiency model — plus your DTE rebate and federal tax credit eligibility. Real numbers based on Detroit gas rates and 2026 incentive programs.

$1,100

Max Rebates

20-40%

Bill Savings

60 sec

To Calculate

5.0 ★

Google Rated

✓ 100% Free Tool

✓ Real Detroit Rates

✓ DTE Rebates Included

✓ Federal Tax Credit

✓ BBB Accredited

✓ Authorized Dealer

1 How Old Is Your Furnace?

Older furnaces lose efficiency over time and were built less efficient to begin with.

0-5 yrs~95% efficient

6-15 yrs~85% efficient

16-25 yrs~75% efficient

25+ yrs~65% efficient

2 Current Annual Heating Cost

Estimate your total winter heating bill (Nov-Mar gas bills). Don’t know? Use $1,800 as Detroit average.

3 New Furnace Efficiency Goal

Higher AFUE = more savings + more rebates. 95% is the most popular choice. 97%+ unlocks the federal tax credit.

90% AFUEStandard efficient

95% AFUEMost popular

97% AFUEMax rebates

98% AFUEPremium

Your Potential Savings

You could save $0/year

10-Year Total Savings

Plus reduced repair costs and longer system life

Current

75% AFUE

Upgrade

95% AFUE

💰

Annual Savings

per year

📊

Monthly Savings

winter avg

⏱

Payback Period

0 yrs

w/ rebates

2026 Rebate Stack For This Upgrade

DTE Energy and federal incentives stack together. We handle all the paperwork.

DTE Energy Rebate

Federal 25C Tax Credit

Total Incentives

Real numbers, real savings. Calculations use AFUE efficiency standards, Detroit-area gas rates, and current 2026 DTE rebate tiers. Actual savings depend on home insulation, weather, and gas prices. Rebate amounts subject to DTE program rules. We provide free in-home assessments for exact savings projections plus financing options on new high-efficiency furnaces.

☎ Get Free Estimate See Installation Info

Big Mike's Heating and Cooling BBB Business Review

BBBAccreditedBusiness

Trusted Authorized Dealer

Big Mike’s is an authorized dealer for Carrier, Lennox, and Bryant — the same brands that qualify for DTE’s highest rebate tiers and the federal 25C tax credit. BBB Accredited, fully licensed, and we handle every piece of paperwork for your rebates at no charge.

View Our BBB Profile →

Why Upgrade With Big Mike’s?

Family-owned, licensed, and an Authorized Dealer for Carrier, Lennox, and Bryant. We install high-efficiency furnaces from every major brand across Wayne, Macomb & Oakland County.

Authorized Dealer

Carrier, Lennox, Bryant — the brands that qualify for max rebates.

Free In-Home Estimates

Manual J sizing and exact savings projections. No obligation.

Rebate Paperwork Included

We file your DTE rebate at no charge. Plus AHRI docs for your federal credit.

Financing Available

Spread the cost over manageable payments. Ask about options.

Real Customer Reviews

5.0 Stars from 15 Google Reviews

When you’re ready to convert this estimate into real savings, here’s who Detroit Metro homeowners trust to do the install.

★ Google

★★★★★

Communication was excellent throughout. Pricing was very fair compared to other quotes I received. Quality of work was top notch.

David Keith

Local Guide · 44 reviews

★ Google

★★★★★

Pricing is the best out of all of them. Communication was great. Will recommend to friends and family.

Brian Ousley

Local Guide · 69 reviews

★ Google

★★★★★

Cheaper than the rest and they did a great job. Would definitely use them again.

Christina Heskett

Local Guide · 29 reviews

★ Google

★★★★★

Amin and team were quick and thorough diagnosing and repairing the furnace. Response time was also very timely. Will recommend and use again.

Lynette Roberson

Local Guide · 148 reviews

Ready to Save?

Get an exact savings number with a free in-home assessment. We’ll size your home properly and show you the full rebate math, no obligation.

☎ (313) 398-0504

Energy Savings Calculator

You could save $0/year

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Why Upgrade With Big Mike’s?

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