[miamicuse]

In general which type of filter is better for central AC?

The blue colored fiberglass ones like this?

or the pleated ones like this?

The pleated ones have a larger surface area, but the fiberglass ones are thicker. Which one is more efficient?

I assume the pleated ones since they seem to be more expensive?

 

[Colbyt]

The blue ones are great if you want to read your newspaper through them.

The pleated ones on a properly sized system do a far better job of catching dust.

 

[crabjoe]

Go Fiberglass for AC performance. The pleated ones can cause air flow restrictions, especially the high MERV ones.

 

[beenthere]

Varies with each system.

 

[user_12345a]

There's a middle ground, you can get merv 6/7 filters which don't restrict flow. Each system is different but if a basic 1" pleat causes low airflow there are other issues like undersized ducts or filter.

If you want high filtration you have to get a 4-5" media filter. High central filtration is a waste though.

 

[Bob Sanders]

In general which type of filter is better for central AC?

The blue colored fiberglass ones like this?

or the pleated ones like this?

The pleated ones have a larger surface area, but the fiberglass ones are thicker. Which one is more efficient?

I assume the pleated ones since they seem to be more expensive?

The reason the pleated ones are pleated is because they must have a larger surface area to make up for the increased air restriction due to finer filtering.

As for which one to use...
If you're looking for simple furnace protection combined with highest operating efficiency then the fiberglass ones are for you. If you're looking to filter air for allergies and such then you want to get into the pleated ones.

If you only have a one inch slot and decide on the pleated ones then you may have to change them a little more often.

 

[user_12345a]

pleat cuts maintenance costs if the system can take it.

With a properly fitting pleat, no bypassing you will never have to get the blower or coil pulled and cleaned. Not so with fiberglass.

Fiberglass filters date back to the days of no a/c, no secondary heat exchanger and low static belt driven blowers not moving much air.

They did the job at the time.

Today a/c is common (coil to clog), high efficiency furnaces with secondary heat exchangers that can clog, larger blowers, high airflow requirements making the fiberglass filters less effective.

 

[supers05]

My boss won't even stock the fiberglass ones if he can help it. We stock pleats and cotton type media. (finer filtration then fiberglass but still less then pleats.) The price difference is insignificant when buying in bulk. (pleats are about +4x the price though) We hate having to rip our units apart to wash the evap coils. (some of our customers have 50 unit's on a single roof alone) When they want to keep things cheap we put in the media type filters. Generally without bypassing, and using the pleats or media type, we don't have to wash those evaporators for the lifetime of the unit.

Cheers!

 

[Bob Sanders]

Today a/c is common (coil to clog), high efficiency furnaces with secondary heat exchangers that can clog, larger blowers, high airflow requirements making the fiberglass filters less effective.

Clogged coils don't happen if you're properly servicing your system (clean/inspect once per year)

 

[raylo32]

My vote for mid-MERV pleated. Been using them for 20 years. They flow just fine and with proper change intervals will keep your coil clean.

 

[miamicuse]

I had a new system put in September 2015. Three months ago. A Rheem MODEL RBHP-17J06SH1 uses 16x21x1 filters. The AC company gave me 12 of the blue filters. I change it once a month.

After 4 months, the handler coil looks like this.

Is this about what you would expect or this is already dirty?

 

[user_12345a]

it should be spotless and remain spotless. not sure if the pictures are just low quality or the coil is getting plugged with dust, hopefully the former.

 

[Bob Sanders]

The coils should be pretty clean, even with a low grade merv2 or 3 filter. As USER points out the pic quality isn't that good so it's hard to tell but if the coils are dirty after 4 months then I would look for an air leak skirting around the filter somewhere. Are the filters the right size? Are they fitting properly? They're being pushed right to the back when inserting?

 

[beenthere]

The coil will get fairly dirty using MERV 2 or 3 filters in the summer. A wet coil is equivalent to a MERV 8 filter.

 

[miamicuse]

In the summer the AC is running a lot here in South Florida where temp is 95 at 150$ humidity.

The coil is not spotless and shiny. It has some white buildup on it which surprises me since it's only been 4 months.

That's why I am wondering if I should use a different type of filter besides the fiberglass one the installer gave me.