Buying an HVAC system shouldn’t feel like you need a degree in engineering. I’m Jake Lawson, and I’m here to help you cut through the fluff and figure out what furnace and AC combo makes sense for your home. Whether you're swapping out an old clunker or building from scratch, let’s break down the key things you need to know to get your money’s worth.
Step 1: Know Your Climate
Your zip code says a lot about your HVAC needs. Live in a place where winters are brutal? You’ll want a high-AFUE gas furnace (95%+). Deal with sweltering summers? Then your AC’s SEER2 rating matters more.
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Cold climates: Prioritize a high-efficiency furnace (AFUE 95%+)
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Hot/humid regions: Look for a high-SEER2 AC (15.2+ SEER2 recommended)
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Mixed climates: You’ll want decent efficiency from both sides without going overboard
Step 2: Size the System Correctly
One of the biggest mistakes I see? People buying units that are too big or too small. It’s not about square footage alone. You need to consider insulation, ceiling height, sun exposure, and more.
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Use a Manual J load calculation (ask your installer or use an online calculator)
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Typical rules of thumb: ~25-30 BTUs per sq ft for heating, ~20 BTUs per sq ft for cooling
Oversizing leads to short-cycling (which kills efficiency), and undersizing leaves you sweaty or shivering.
Step 3: Match Your Components
Don’t pair a new 2-stage furnace with a single-stage AC, or mix brands that aren’t AHRI certified together. Matched systems run better, last longer, and keep warranties valid.
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Stick with matched systems from one brand (like Goodman combos)
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Check AHRI certificates to confirm performance and compatibility (AHRI Directory)
Step 4: Understand Your Ductwork
Got ductwork that’s older than your first car? It may not handle today’s high-efficiency systems well.
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Inspect for leaks or gaps (especially in attics and crawlspaces)
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Consider duct resizing if moving to a variable-speed system
You can have the best equipment in the world, but if your ducts are a mess, your comfort and efficiency go out the window.
Step 5: Budget for the Total Package
Price matters—but so does value. A cheap system that runs up your energy bill every month isn’t really saving you anything.
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Factor in rebates/tax credits (especially for ENERGY STAR systems)
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Look at lifetime costs – not just install price
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Think long-term: higher SEER2 and AFUE systems pay off in energy savings
Final Word from Jake
At the end of the day, the right furnace and AC combo is the one that fits your home and your needs. Don’t buy what your neighbor bought—buy what makes sense for your climate, budget, and layout. And if it comes with R-32 refrigerant? Even better—you’re ahead of the curve.
Start shopping smart with The Furnace Outlet’s R-32 AC and Gas Furnace Combos.
