When folks ask me why their electric furnace isn’t working the way they expected, airflow is often the silent culprit. I’m Mike Sanders, your no-nonsense HVAC neighbor, and today I want to break down why airflow is the unsung hero of heating efficiency—especially for electric furnaces like the Goodman 68,240 BTU 20 kW Electric Furnace.
What Is CFM and Why Should You Care?
CFM stands for Cubic Feet per Minute—basically, how much air your furnace moves through your ducts every minute. This Goodman model delivers 2,000 CFM, which is ideal for heating a 2,000 sq ft home, assuming your ductwork and vents are in decent shape.
If your airflow is restricted (dirty filters, crushed ducts, or closed vents), the system has to work harder, and efficiency drops like a rock.
👉 Want to get nerdy? Check out HVAC School’s deep dive on CFM and static pressure. They break it down for techs, but it’s readable for motivated homeowners too.
Signs Your Airflow Is Hurting Efficiency
You might be losing efficiency without even knowing it. Here are red flags:
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Uneven heating from room to room
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Long run times
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High electric bills
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System short-cycling (turning on and off too frequently)
If you’re dealing with these, your airflow might be too low.
How to Improve Your Furnace’s Airflow
Let’s fix that. Here’s what you can do right now:
1. Change Your Filters (Seriously)
Dirty filters are the #1 airflow killer. Swap them every 30–90 days. Go for MERV 8–11 if you want good filtration without choking your system.
Need help choosing a filter? Energy Star’s filter guide is a solid place to start.
2. Check for Blocked or Closed Vents
Make sure vents aren’t blocked by furniture or rugs. Closing too many can mess with pressure and flow.
3. Inspect Ducts for Leaks or Collapses
Leaky ducts can bleed warm air into your attic or crawlspace. A good DIY check: turn on your furnace fan, then walk around with incense and see if smoke gets pulled into or out of joints.
4. Schedule a Static Pressure Test
This one’s for the pros, but it’s worth it. Techs can test your system’s pressure to find hidden restrictions.
The Math of Efficiency
If your system is pulling in 2,000 CFM and delivering 68,240 BTUs, every CFM that makes it into your rooms counts. Poor airflow forces longer runtimes, more electricity, and more wear and tear.
Here’s a rough example:
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Ideal airflow = 2,000 CFM → System runs 5 hrs/day
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Bad airflow = 1,500 CFM → System runs 6.5 hrs/day
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At $0.13 per kWh: That’s ~$1.95/day extra, or $58.50/month in waste
It adds up fast.
Final Thoughts from Mike
Look, heating your home isn’t just about BTUs—it’s about moving those BTUs around efficiently. Airflow is the river that carries the heat, and if that river’s dammed up, even the best furnace will struggle.
So keep your filters clean, inspect your vents, and treat your ducts like the lifelines they are. And if you haven’t yet picked up a system, I highly recommend starting with something proven like the Goodman 20 kW electric furnace—but only if you plan to give it the airflow it deserves.
Got questions? I’m always around. Drop a comment or shoot us a message at The Furnace Outlet. We’re all in this to stay warm and keep it simple.
