10 Common HVAC Myths Debunked

Misinformation about HVAC systems costs homeowners money and comfort. Let's separate fact from fiction.

Myth 1: Bigger Is Always Better

The Truth: Oversized systems cycle frequently, waste energy, and fail to control humidity properly. Proper sizing through load calculations is essential.

Myth 2: Closing Vents Saves Energy

The Truth: Closing vents increases duct pressure, can damage equipment, and rarely saves meaningful energy. Keep most vents open.

Myth 3: Thermostat Location Doesn't Matter

The Truth: Thermostats near heat sources, in direct sunlight, or on exterior walls give inaccurate readings and cause comfort problems.

Myth 4: Maintenance Isn't Necessary

The Truth: Skipping maintenance reduces efficiency 5% annually and dramatically shortens equipment life. Annual tune-ups pay for themselves.

Myth 5: Setting Temperature Lower Cools Faster

The Truth: Your AC delivers air at the same temperature regardless of setting. Setting it lower just makes it run longer, potentially overshooting your comfort zone.

Myth 6: Ceiling Fans Cool Rooms

The Truth: Fans cool people through evaporation, not rooms. Running fans in empty rooms wastes electricity.

Myth 7: You Only Need to Change Filters Annually

The Truth: Most filters need monthly checks and replacement every 1-3 months. Dirty filters reduce efficiency and damage equipment.

Myth 8: Higher MERV Filters Are Always Better

The Truth: High-MERV filters can restrict airflow if your system isn't designed for them. Match filter rating to your equipment.

Myth 9: Refrigerant Needs Regular Topping Off

The Truth: Refrigerant doesn't deplete during normal operation. If you need refrigerant added, you have a leak that needs repair.

Myth 10: Turning Off AC When Leaving Is Best

The Truth: Moderate setback (7-10°F) saves more than turning off completely, which forces the system to work hard to recover.

The Bottom Line

Good HVAC decisions require accurate information. When in doubt, consult a qualified professional rather than relying on conventional wisdom that may be wrong.