Air Conditioning Filters
Which Ones Should You Use?
Air Conditioning Filters were originally created to protect air conditioning units from dust and dirt building up on coils, fan motors, and blower wheels.
This is because dirt and dust on your a/c components ultimately leads to pre-mature failure of your a/c system, causing coils to freeze, blower wheels to carry more weight than designed, and blower motors and compressors to fail.
As time progressed and homes became more air tight, the EPA found that their was a need for better indoor air filtration for health reasons.
ASHRAE - The American Society of Heating, Refrigeration, and Air Conditioner Engineers created the MERV (Minimum Efficiency Reporting Value) system for rating different air filters and their effectiveness at removing airborne particles. MERV values vary from 1 to 16. The higher the MERV value, the more efficient the filter will be in trapping airborne particles.
Which Air Conditioning Filters to Use
From An A/C Technicians Perspective
If their are enough restrictions to airflow in an a/c system it will result in pre-mature system failure. So it would be fair to say, actually, it is a FACT that an Air Conditioning system operates best when there are no restrictions to airflow.
However, adding an air conditioning filter to an Air Conditioning System restricts this airflow to some degree, (more or less depending on the type of air filter used) but the air filter is a necessity because it also helps prevent dirt and dust build up from accumulating onto your coils, fan motors, and blower wheels - again (more or less depending on the type of air filter used) which over time, if the wrong air filter was used, could rapidly restrict air flow and cause the above problems.
So we know that an air filter is a restriction but it's also a necessity to prevent further restrictions. What do you think happens when your air filter gets dirty? That's right! It restricts more air flow.
Dirty Air Conditioning Filters
Dirty air conditioning filters cause several problems in your system including increased operating costs (utility expenses), lower comfort levels, compressor damage, and reduced humidity removal.
Keeping your air filters clean means clean system operation, lower electric bills, better dehumidification, better air flow, improved cooling, and a cleaner home.
MERV Rated Air Filters and What They Mean for You and Your Residential A/C Unit
The bottom line is that higher MERV rated filters MERV 9 thru 12 are more efficient at trapping airborne particles, which is a better option for preventing air restrictions in your ac units coils, and they are a better option for indoor air quality(allergy sufferers) However, this same higher MERV rated filter may also cause the efficiency of your a/c unit to under perform if not changed frequently enough. Most residential systems can handle up to a 12 MERV rating without any problems, but more frequent air filter changes are highly recommended.
Lower MERV rated filters MERV 1 thru 4 are less efficient at trapping airborne particles, which initially is good for your a/c systems performance, but gradually dirties your coils and causes parts to prematurely fail, ultimately causing more unseen problems down the road. Not to mention that they do absolutely nothing for your indoor air quality.
This leaves us with MERV 5 thru 8 and ultimately to our sweet spot! That's right, a filter that doesn't restrict too much airflow, but also does an awesome job at capturing airborne particles to protect your a/c unit and to protect your health.
The Sweet Spot
As seen from the MERV rating chart below, MERVs 1-4 have a less than 20% efficiency at removing airborne particles. This means that up to 80% of the airborne particles passes through these air filters and lands on the coils of your unit and on your lungs.
MERVs 5-7 have an efficiency of 20% to 69%.
And MERV 8 has a 70% to 85% efficiency.
MERVs 9-12 have a 85% to 90% efficiency.
Any MERV rating above 12 should NOT be used for residential purposes. MERVs 13-16 are used mainly for commercial, industrial, hospitals, and clean rooms.
Our Sweet Spot is the MERV 8 Air Filter. As it's the most efficient filter at trapping the 3 to 10 sized micron particles before getting into the more highly restrictive air filters - (9 and up) which trap 1 to 3 sized micron particles, and all the way down to .3 to 1 micron.
If you are an allergy sufferer, I wouldn't put a price tag on your health and would go with the MERV 12 Air Filter.
However, if you're looking for the BEST all around air filter that contains the perfect balance between your health and the health and efficiency of your a/c unit, the MERV 8 Wins hands down!
What About FPR and MPR Ratings?
FPR (Filter Performance Rating) and MPR (Micro Particle Rating) are rating systems that were developed by home improvement and air filter manufacturers. They are not related nor can they be compared to MERV ratings.
These ratings systems are not endorsed by ASHRAE, (The American Society of Heating, Refrigeration, and Air Conditioner Engineers) and we do not recommend using filters not rated under the MERV system for two (2) reasons.
1. First of all, it's better to leave an Air Conditioners air filtration to Air Conditioning Engineers. After all, they designed and built the units.
2. Secondly, these other ratings leave to much to question as to their efficiency and the effects that they will have on your a/c unit. Are you willing to roll the dice?
Periodic Air Conditioning Maintenance checks and cleanings should be performed on your air conditioner.
By using the proper Air Conditioning Filters, changing your air filter frequently, and
performing regular maintenance checks and cleanings,
you can rest assured that you'll have proper air flow delivery, increased comfort level, healthier indoor air, and better dehumidification.
Air Conditioning & Heating
Repair & Service
1334 W. Pepper Pl
Mesa, Arizona 85201
Air Conditioning Phoenix and the following cities in Arizona: Glendale, Peoria, Scottsdale, Tempe, Chandler, Gilbert, Mesa, Queen Creek, Gold Canyon, Apache Junction, and Florence.
Types of systems we service: Air Conditioner, Heat Pump, Gas Heating, Furnace, and Electric Heat.
Brands we service: All major brands including: Mastercool, Trane, Amana, Ruud, Goodman, Carrier, York, Goettl, Payne, Lennox, Rheem, Bryant, Heil, Kenmore, and Coleman.
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