A $20 air filter can save you thousands in AC repairs and hundreds on energy bills. Yet 82% of AC breakdowns are caused by dirty filters. This simple maintenance task takes 5 minutes but can extend your AC's life by years.
The Hidden Cost of Dirty Filters:
- • 15% higher energy bills ($40-60/month)
- • Frozen evaporator coils ($500-1500 repair)
- • Compressor failure ($2000-4000 repair)
- • Poor air quality (health issues)
Filter Replacement Schedule by Type
Standard Fiberglass Filters (1" thick)
Replace Every: 30 days
Cost: $2-5 each
MERV Rating: 1-4
Basic protection, catches large particles only. Cheapest but least effective.
Pleated Filters (1" thick)
Replace Every: 60-90 days
Cost: $10-20 each
MERV Rating: 5-8
Good balance of filtration and airflow. Best choice for most homes.
High-Efficiency Pleated (1" thick)
Replace Every: 90 days
Cost: $20-40 each
MERV Rating: 9-12
Excellent filtration but can restrict airflow in older systems.
Thick Media Filters (4-5" thick)
Replace Every: 6-12 months
Cost: $40-80 each
MERV Rating: 11-16
Professional-grade filtration, requires compatible system.
Change Your Filter MORE Often If You Have:
Pets
1 pet: Change 2x more often
2+ pets: Change monthly regardless of filter type
Allergies/Asthma
Change every 20-45 days and use MERV 11+ filters
Large Family (5+ people)
More activity = more dust. Change 30-45 days
Construction Nearby
Check weekly, change monthly during projects
Smoking Indoors
Change every 30 days, use carbon filters
Running AC Constantly
Summer in San Antonio = change monthly
How to Check If Your Filter Needs Changing
The Light Test:
Hold filter up to light. If you can't see light through it, replace immediately.
Visual Signs to Replace:
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Filter is gray, brown, or black (should be white/off-white)
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Visible dust/pet hair coating
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Filter is bent, warped, or damaged
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Can't remember last change date
System Signs of Dirty Filter:
- • Weak airflow from vents
- • AC runs longer to cool home
- • Higher electric bills
- • Dusty home despite cleaning
- • Ice on AC unit
- • System shuts off unexpectedly
How to Change Your Filter (Step-by-Step)
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1
Turn off AC system at thermostat (prevents dust from circulating)
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2
Locate filter slot - Usually behind return air grille or in air handler
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3
Note filter size - Written on filter edge (e.g., 20x25x1)
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4
Remove old filter - Slide out carefully to avoid spreading dust
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5
Check airflow arrow - Must point toward AC unit/ductwork
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6
Insert new filter - Ensure snug fit with no gaps
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7
Write date on filter - Use permanent marker for next change reminder
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8
Turn AC back on - Set reminder for next change
Money-Saving Filter Tips
Buy in Bulk
Purchase 6-12 filters at once for 20-30% savings. Store in dry place.
Subscribe & Save
Filter delivery services offer 10-15% discounts and never forget changes.
Right MERV Rating
MERV 8 is perfect for most homes. Higher isn't always better.
Set Reminders
Phone alerts prevent emergency service calls from neglected filters.