Home HVAC filter recommendations ?

Central system. I'm inclined to choose the higher filtration 3M product but I'd like to get some opinions. 
 

Go!

Buy the cheap greeny 3 packs 

Cheap. The fancy ones do a better job filtering, at the expensive of taxing the system, at least according to the employee that pointed me at the 3 for $10 filters instead of the $20 one I was looking at. 

In reply to RevRico :

For an allergy sufferer like me can tell a huge difference in the air at home with cheapie air filters vs the nice 3M versions. 3M version FTW!

In reply to RevRico :

I understand that better filters typically mean more work for the fan, but I'd like to see real evidence it's harder on the systems. In a decade of owning different homes, I've haven't seen any difference in using better filters, in regards to efficacy or reliablity of a system. 

In reply to z31maniac :

I have no evidence. Just not used to employees pointing out the cheaper option. 

I get 3 packs of cheap 3m at Sams club now. I've looked at the two inch thick super hepa infinitum filters and eh, my filters really don't get that dirty between changings so I haven't bothered trying them.

In reply to Floating Doc (Forum Supporter) :

I've had quite a few air filter discussions in the last year and a half so here goes:  Air filters are about the MERV rating.   The higher the number, the higher the initial efficiency but also the higher the resistance to air flow.   As an example the cheaper fiberglass media air filters are rated at MERV 4 and are less than 20% efficient.  They do trap some dust and dirt but they're the bare minimum.  The typical 1" pleated media filters at the big box stores are MERV 7 or 8 and are 30-35% efficient. These are the baseline filter that I'd recommend, they work well and will operate without issue in almost every system.   

I upgraded my systems to MERV 11 pleated media (still standard sizes, mine are 16 x 20 x 1 and 20 x 25 x 1)  These are 60-65% efficiency and I have not noticed any change in system airflow.    Similar rated filters at the big box stores are a bit pricey, I've been buying mine a box at a time online and it's quite a bit less on a per filter basis.  https://www.discountfilters.com/  They have water system and refrigerator filter lines as well.  I haven't needed to order anything in the past 6 months, the times I've ordered prior to that they had stock on hand and they were easy to deal with.

It's possible to go higher in efficiency, true HEPA filters are above 95% efficiency (MERV 15 up to MERV 20) but have much higher pressure drop across the filter media that almost always require that they be considered in the design of the system.  I've only come across filters in this range in hospital, lab and clean room applications.  Note that if we're on a quest to arrest airborne virus and similar sized particles you need to be in the true HEPA range.   

The system is designed to work with a filter. The resistance of a good filter will not damage the system. 
 

Would you drive your car without a filter, or with a crappy one?

The system WILL lose efficiency and be damaged when more and more airborne particulate gets sucked through a crappy filter. 
 

Don't trust minimum wage workers at Sam's club to offer excellent advice on maintaining your HVAC system. 

I tend to buy the cheapest pleated filters I can find.  The key is to change them regularly.  I've seen filters in some folks' houses that defy description.

I used to just buy the 3M pleated ones whenever they'd go on sale at Costco, but lately I bought a big box of NordicPure ones from Home Depot. Wirecutter reccomended them, and they generally steer me in the right direction.

In reply to 11GTCS :

Thank you for that, Like  Revrico I had been told the pleated would not let the system "breathe".  I understand it better now!

In reply to Tom_Spangler (Forum Supporter) :

I've been using NordicPure in our current house and am pretty happy with them. 

I buy the pleated ones (Mostly 3m when available) and change them monthly because I have birds.

(Dust, dander, yuck.)

11GTCS said:

In reply to Floating Doc (Forum Supporter) :

I've had quite a few air filter discussions in the last year and a half so here goes:  Air filters are about the MERV rating.   The higher the number, the higher the initial efficiency but also the higher the resistance to air flow.   As an example the cheaper fiberglass media air filters are rated at MERV 4 and are less than 20% efficient.  They do trap some dust and dirt but they're the bare minimum.  The typical 1" pleated media filters at the big box stores are MERV 7 or 8 and are 30-35% efficient. These are the baseline filter that I'd recommend, they work well and will operate without issue in almost every system.   

I upgraded my systems to MERV 11 pleated media (still standard sizes, mine are 16 x 20 x 1 and 20 x 25 x 1)  These are 60-65% efficiency and I have not noticed any change in system airflow.    Similar rated filters at the big box stores are a bit pricey, I've been buying mine a box at a time online and it's quite a bit less on a per filter basis.  https://www.discountfilters.com/  They have water system and refrigerator filter lines as well.  I haven't needed to order anything in the past 6 months, the times I've ordered prior to that they had stock on hand and they were easy to deal with.

It's possible to go higher in efficiency, true HEPA filters are above 95% efficiency (MERV 15 up to MERV 20) but have much higher pressure drop across the filter media that almost always require that they be considered in the design of the system.  I've only come across filters in this range in hospital, lab and clean room applications.  Note that if we're on a quest to arrest airborne virus and similar sized particles you need to be in the true HEPA range.   

THIS.

Filters have a sweet range.  Too low won't trap enough junk and too high WILL substantially impact the performance of your system due to reduced airflow.

Mid-priced filers are where you want to be.  I tend towards the 3M ones with the purple packaging.

Do any of you have any experience with the anti-static, cleanable metal filters? 

The HVAC company I use to do the twice yearly tune ups for everything recommend them, but of course you're likely to recommend what you sell. 

They work decently well until you inevitably forget to clean them. Then they don't.

In reply to Duke :

Good to know. We have to replace out filters monthly because of the insane amount of dust that gets blown around in OKC (like literally it blows so much and so hard, it puts dust through the window seals)...............and we have 3 dogs and a cat. 

BoxheadTim said:

In reply to Tom_Spangler (Forum Supporter) :

I've been using NordicPure in our current house and am pretty happy with them. 

Same, run a MERV11 on mine and changed monthly with 2 dogs in the house.  

I'm in the HVAC business. MERV 11 seems to be the threshold that takes most common alergens out of the air as well as dust from the West coast fires. I don't recommend over MERV 13 for residential systems. 

Do NOT get self-charging electrostatic filters. They do a fine job, but have a very limited surface area so they clog up really fast which is bad for furnaces and extremely bad for air conditioners.

I recommend extended surface pleated filters, which is to say pleated filters that are four or five inches deep and come in their own cabinet. The reason is that the surface area is so much greater than a 1" filter, and as such they'll take a lot longer to clog up.  

I used to have the washable filters because I hug trees and I'm not an allergy sufferer.  They are the ones that kinda look like a 3M scotchbrite pad in a plastic frame.  I think they were rated MERV4 and  I really couldn't take the dust.  I was constantly dusting my house and the next day it looked like I hadn't dusted in weeks.  I switched to the tree-killing kind and got a case of good MERV11 rated filters and what used to take a week to get dusty now takes months.  Very happy.

I got some of these.

Pleased as punch.

MERV ratings and what they catch and don't catch

A decent HVAC system should have no issue with pleated filters.  I may be cursing myself by saying this, but our system is 18 years old, and has a massive Aprilaire 2200 pleated filter setup the whole time.  It does seem to work well.

Sine_Qua_Non said:

In reply to RevRico :

For an allergy sufferer like me can tell a huge difference in the air at home with cheapie air filters vs the nice 3M versions. 3M version FTW!

Same allergies issue for me, so when I had a major furnace repair in my last home, I also changed to a 5 or 4 inch thick MERV 11 or 13 filter. 

Greater thickness and above 11 MERV gives cleaned air, longer life, and less drop-off of performance between replacement. 

I vacuum out my pleated filters with a shop vac and brush attachment to extend their life. The fluffy 3M ones quickly fall apart but I like the paper looking DuPont ones better. Once the filters fill up with dust, doesn't that MERV number go up, right?