re: washable filters: tell me why they are awful

[mtbike]

As I stated from the first post, I am using other disposable media and don't plan on changing to washable, I just want to learn why they are not recommended.

Homeowners don't wash them as often as needed, they are too coarse to effectively filter the air.

what characteristic of filter makes it "too coarse"?

there are 2kinds of washable filters the metal mesh ones and the plastic mesh ones and the metal one is worthless and the plastic one are very restrictive.

can you be a little more descriptive on why it is worthless.

[Curato]

Not all electrostatic filters are the same. Most are washable, but not all are life time filters. Find out what type of media is used on the inside. If foam or polyester is used it is not a life time filter. Foam deterriorates and polyester will clog up and can't be cleaned.
1. Pressure drop. Find out what the final resistance is. A happy medium needs to be maintained between efficiency (capturing particles) and restricting air flow.
2. Cleaning is recommended every 3 months.
3. Permanent filter media should not degrade with normal use. However, if a UV light is present it could damage the media.
4. Merv values. Unfortunately some companies may exaggerate, but you can always ask for the test results. Merv 7-8 will work fine for most homes.
Hope this helps. Check out airclean.com for more information

[Cookiemanhvac]

Media filters rock. Most people don't wash washable filters enough. It's easier for me to use a 4" media and replace it once or twice a year. Knowing it's doing a great job filtering with minimal pressure drop. If your a tight wad a washable filter may be good for you. Do you still have the first dollar you made? Lol

[ACFIXR]

Personally I have always used standard media in my furnace, but that is not what this post is about.

It seems to be a consensus here that washable filters are awful.

Ok. But I want to understand as many reasons why they are awful in comparison to other media.

1. Do they increase pressure drop? Is the airflow decreased through the filter? is this have to do with a non-pleated surface area?
2. How often are these filters cleaned in comparison to the standard 3 month for media.?
3. I have read here that degrade over time. how does this happen?
4. are advertised MERV values inflamed?

tell me some other reasons why these things are awful.
thanks
-mtbike

Permenant washable filters are great because when new systems are installed the typical installing contractor is "air filter ignorant" and has no clue what the difference is between 500 fpm and 300 fpm and tries to put the proverbial square peg into a round hole. I save all of my permenant filters from installs and use them where ignorant contractors have not set up the proper filter racks for their customers.