Boring HVAC Statistics That Nobody Cares About (But Probably Should)
Last Updated on May 30, 2025 by Chad Peterson
These boring HVAC statistics are not only boring, they are downright scary, and they might explain your high energy bills, poor airflow, or why your system might even suffer an early death.
Few people pay attention to their HVAC system until something breaks. But when I run a “no heat” or “AC blowing warm air” call, there is a boring statistic that could’ve warned you. Here are the dull-but-deadly HVAC statistics that quietly lurk inside your HVAC system — and your wallet — into the ground.
1. 82% of homeowners don’t change their HVAC filters at the correct time
Clogged filters reduce airflow, overwork your blower motor, and wreck efficiency. I’m not pointing my finger at you because I have four fingers pointing back at me. Neglecting to change my filters is easy. One of them is in the attic, and the other costs a lot of money.
But I have a method that keeps my units running smoothly. If you are inclined to read, I can elaborate more in an article I wrote specifically for that, if you click here.
2. Heating and cooling account for 50% of a home’s total energy use
That “boring” system that was installed to keep your home comfortable could be eating up half your power bill. I’m sure that’s an average. But, where do you fall into that average, high, or low? My electric bill is an average monthly cost of each month, which they call equal-pay.
It took a big jump this year, and I know I’m not alone. My only solace is that when talking to my neighbor who has a similar home, but slightly smaller, his bill is higher than mine. It’s a good way to compare.
3. Leaky ducts waste up to 30% of conditioned air
You paid to cool the attic, crawlspace, and behind your walls. Nicely done. And that’s no foolin! In my over four decades of experience in the HVAC industry, I am fully convinced that duct sealing is more effective than duct insulation.
Proper duct sealing cures several ailments. It puts the conditioned air where it belongs (in you home) and it provides a way to properly clean and purify the air.
4. A 1°F thermostat adjustment can reduce heating costs by 1%
If you are on a skinny budget, this one could help you through the month, maybe a little bit. But as long as I can afford to keep my house comfortable, that’s probably what we will do. There are those times when multiple people live in a home, and you can’t please them all. That’s when you have to dress differently. And 68°F doesn’t mean you’re suffering.
5. Indoor air can be 2 to 5 times dirtier than outdoor air
We used to educate our employees and our customers by teaching them that a house is like an envelope. You don’t want to be filtering outside air any more than necessary. Having sealed duct work and the best filter for your system can’t be beat.
6. A dirty blower and wheel can cut airflow by 30%
This isn’t necessarily where your dust comes from, but it is where it can accumulate. Each little layer of dust on a blower wheel reduces the efficiency of your whole system. Next time your service technician opens your furnace for inspection, ask them to show you the blower wheel. Scope it out with a good flashlight.
7. SEER ratings drop 5–15% when coils are dirty
Coils are like a secondary filter. Everything that gets by or through your filter gets buried in your AC coil (a coil is like the radiator in your car). High-efficiency gas furnaces have another coil called a recuperative coil that does the same thing. That efficient new system? It isn’t —or it won’t be for long if the proper maintenance isn’t done.
8. Most HVAC units last 15 to 20 years
Or 10, if you think “annual maintenance” is a scam. I can’t add much to that statement.
9. High-MERV filters can damage your system
Yes, you can over-filter. Your furnace isn’t a jet engine. The HEPA filter craze is detrimental to some systems. Your system has to pass so much air relative to its ductwork and BTUs. By adding a filter that is too efficient your system will labor beyond it’s ability to stay within its design.
10. 90% of summer HVAC service calls are refrigerant or electrical issues
Not magic. Not cursed. Just overlooked.
Conclusion
I love the HVAC industry. It’s highly overlooked and pretty boring to most people unless they are too hot or cold. It’s not even interesting. But these numbers are why your system fails when you need it most — or why your energy bill makes your eyes water.
Boring? Absolutely. But ignore them, and you’ll care soon enough.
