The HVAC myths we hear most often are that closing air vents saves energy, that cranking the thermostat cools a home faster, that a bigger AC unit performs better, and that skipping maintenance saves money. Each one usually raises energy bills instead of lowering them. At Comfort Plus, LC Heating and Cooling, based in Troy, MI, we want homeowners to have the facts before changing a setting or skipping a repair.
Does Closing Air Vents Save Energy?
Closing vents in unused rooms does not lower energy use. Central HVAC systems move a set volume of air through every vent, and any HVAC company will confirm this is by design.
Closing several vents raises duct pressure, forcing the blower motor to work harder and often pushing conditioned air out through small leaks. Homeowners who want to stop conditioning a spare room are better off using a zoning system or a smart thermostat with room sensors instead.
Does Setting the Thermostat Lower Cool a Home Faster?
No. An air conditioner cools at one speed, regardless of thermostat setting. Setting it to 60°F instead of 72°F won’t cool the home faster; it just runs longer and overshoots the target.
Per the U.S. Environmental Protection Agency, the Department of Energy suggests setting the thermostat 8-10°F back while away or asleep rather than overriding it with an extreme number.
Does a Bigger AC Unit Cool a Home Better?
An oversized unit cools quickly, then shuts off before removing enough humidity from the home. That short-cycling pattern leaves rooms feeling clammy and wears out components faster. Heating and cooling already make up close to half of a typical home’s annual energy bill, more than $900 on average, according to ENERGY STAR, so a poorly matched system has an outsized effect on cost.
The right size comes from a proper load calculation, not a guess based on the old system. Our team at Comfort Plus Heating & Cooling runs that calculation before any air conditioning installation in Troy.
Does Skipping Maintenance Save Money?
Deferred maintenance is one of the most expensive myths on this list. A furnace or AC unit that never gets a tune-up loses efficiency gradually, so higher bills go unnoticed until a breakdown forces a call for HVAC repair in Troy, MI.
Routine furnace maintenance and seasonal AC tune-ups catch problems, like a dirty coil or a failing capacitor, before they become a full failure.
Myth vs. Reality at a Glance
| Common Belief | What Actually Happens |
| Closing vents saves energy | Increases duct pressure and can cause leaks |
| Lower thermostat setting cools faster | Same cooling speed, longer runtime |
| Bigger AC unit cools better | Short-cycles and leaves humidity behind |
| Skipping maintenance saves money | Efficiency drops and breakdown risk rises |
| Ceiling fans lower room temperature | Fans only create a wind-chill effect on skin |
Why Do These Myths Keep Circulating?
Most of these habits sound logical on the surface. Closing a vent feels like turning off a light in an empty room, and lowering the thermostat further feels like pressing harder on a gas pedal.
HVAC systems aren’t designed to respond that way, so following the logic tends to cost more over time. Experienced HVAC contractors see these patterns often, which is why our technicians explain how each system works during every HVAC repair or maintenance visit.
Frequently Asked Questions
- How often should a home’s HVAC system get professional maintenance?
Twice a year: once for the furnace before winter, once for the AC before summer.
- Do ceiling fans actually lower the temperature of a room?
No. Fans create a cooling effect on skin but don’t change a room’s actual temperature. Turn them off when leaving to avoid wasting electricity.
- Is it true that following these habits can void a manufacturer’s warranty?
It can. Many manufacturers require documented maintenance to keep a warranty valid, so skipping tune-ups can cost more if a covered part fails.
Get an Honest Answer for Your Home
We provide HVAC repair, maintenance, and installation for homeowners based in Troy, MI, and we regularly serve surrounding communities including Berkley, Clawson, and Birmingham. Every home in Oakland County has its own layout, insulation, and airflow needs, so the right fix isn’t always the same from house to house. If a habit you’ve relied on for years has you second-guessing your system, Comfort Plus Heating & Cooling can take a look and tell you what’s really happening. Call us at (248) 280-2800 or email info@comfortpluslc.com to schedule a visit.
