Pleated Filters?
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Jadnashua
Retired Defense Industry Engineer xxx
Depends on the design. It also depends on how much crud you want the filter to capture. A higher MERV value means it will trap more. Having a larger surface area means it can do that for longer before it clogs up. A pleated filter will have more surface area, while tending to allow the same flow, but with better filtering.
Your manual may tell you the maximum MERV value you can use and still achieve the design airflow, or if not, call the manufacturer for their guidance. Some cheap filters don't really capture much.
If you want to maximize flow, don't run a filter! But, you'll be cleaning things frequently, or find that the equipment gets all funky from the crud that gets into the a/c evaporator coils.
Your manual may tell you the maximum MERV value you can use and still achieve the design airflow, or if not, call the manufacturer for their guidance. Some cheap filters don't really capture much.
If you want to maximize flow, don't run a filter! But, you'll be cleaning things frequently, or find that the equipment gets all funky from the crud that gets into the a/c evaporator coils.
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WorthFlorida
Clinical Trail 5th session completed 4/24/24.
The high price & performance filters usually have a MERV rating of 13 and will block air flow a lot sooner since it traps very small particles. With a blocked up filter icing will occur and this tech probably has had hundreds of service calls and all it was a well plugged up filter. The very cheap ones that are filber glass only stops nothing smaller than bowling balls. You'll have very dirty coils in the air handler and that lowers the efficiency and more cleaning of the coils.
Home Depot & Honeywell uses their own numbers game "Filter Performance Rating (FPR)". https://www.airfiltersdelivered.com/merv-mpr-fpr-ratings
I've been using MERV 8 pleated filters forever and I have lived in Florida for 30 years where the air handler runs almost everyday. Newer thermostats have a 500 hour filter change reminder program and if you follow that schedule everything will be fine. I write the date on the filter as I install it. 500 hours or nor I change the filter about every 90-120 days. If you do any construction inside the home such as breaking up old floor tile and create a dust cloud, yes the filter will plug up in one day and cause icing. It happened to me.
Home Depot & Honeywell uses their own numbers game "Filter Performance Rating (FPR)". https://www.airfiltersdelivered.com/merv-mpr-fpr-ratings
I've been using MERV 8 pleated filters forever and I have lived in Florida for 30 years where the air handler runs almost everyday. Newer thermostats have a 500 hour filter change reminder program and if you follow that schedule everything will be fine. I write the date on the filter as I install it. 500 hours or nor I change the filter about every 90-120 days. If you do any construction inside the home such as breaking up old floor tile and create a dust cloud, yes the filter will plug up in one day and cause icing. It happened to me.
This is definitely a system design issue. There is a pleated filter solution for almost any system, and they are the PREFERRED solution, but they aren't cheapie 1" deep filters. Even MERV 13 filter in a system designed for <400 feet per minute velocity at the filter can deliver a very low static pressures well under 0.2" w.c. , and ULTRA clean air (even get's most of the PM2.5).
To get the really low static pressures and super filtering capability it usually takes a bit of sheet metal work to accomodate an Aprilaire 2400 or similar, but worth it for anyone with allergies. The thickness/depth of the media element of better pleated filters is on the order of 4-10" not the 1" cheap glass filters that don't stop anything smaller than a moth (or a mouse). But the total surface area of those very deep fan-folded pleats is many times the cross sectional area of the duct, and the static pressure drop is very low. With better filters the heat pump coils stay clean, as do the ducts.
To get the same low low pressure drops out of a 1" pleated filter the velocity at the filter has to be under 200 feet per minute, which is possible to achieve in some systems, harder in others.
I ended up installing an Aprilaire 2400 (~8" deep media)at my house (my kid has athsma), and usually run MERV 11 or better media in it, swapping it out once a year. When the hamster escaped and (fortunately) ended up in a return duct he started making a nest out of the stuff, and survived well, none the worse for wear when I pulled it out. The media replacement cost about as much as a new hamster though...
To get the really low static pressures and super filtering capability it usually takes a bit of sheet metal work to accomodate an Aprilaire 2400 or similar, but worth it for anyone with allergies. The thickness/depth of the media element of better pleated filters is on the order of 4-10" not the 1" cheap glass filters that don't stop anything smaller than a moth (or a mouse). But the total surface area of those very deep fan-folded pleats is many times the cross sectional area of the duct, and the static pressure drop is very low. With better filters the heat pump coils stay clean, as do the ducts.
To get the same low low pressure drops out of a 1" pleated filter the velocity at the filter has to be under 200 feet per minute, which is possible to achieve in some systems, harder in others.
I ended up installing an Aprilaire 2400 (~8" deep media)at my house (my kid has athsma), and usually run MERV 11 or better media in it, swapping it out once a year. When the hamster escaped and (fortunately) ended up in a return duct he started making a nest out of the stuff, and survived well, none the worse for wear when I pulled it out. The media replacement cost about as much as a new hamster though...
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