A/C filters

[Splitter]

So many types,what do the Pros suggest.There are some that look far to thin on insulation,there are others that look better and they are pleated.others are washable,etc.Can they go longer then 30 days,some say 60-90 days before the change.I run the A/C 97% of the year in Fl. I found a company called NORDIC,are they better than the big box stores? Thanks

[2old2rock]

I always suggest 5" media air cleaners. Inexpensive and keeps nearly every spec of dust out of your coils.

[bx24]

Depends..I run a washable grill filter upstairs and a washable down by the furance...clean every 30 days in the summer...Winter I run a 1" MARV 8...In my other house in TX, I run (3) washables and clean every 30 to 45 days...Works fine for me...coils and motors are clean as can be..

Each person is different..I had a spaceguard in another come and worked nice but was a pain and $$ to replace...

[Southern Mech]

use pleated, more surface area and filter a smaller micron level.

The deal as said above is 4-5'' filter housing just at your a/h or furnace.

[Splitter]

Thanks for some advice.Here is a follow up ??? We purchased another home and there is a filter in the wall grill in D/R.Just on the other side is where the 4 ton A/H sits on an Insulated box and the unit is also insulated as it is in the garage.There is a slide rack for another filter.Is 2 merv #4-8 ok or will there be any problem with R/A and hurt the sytem.Any advice...what would work.

[cobradb]

does anyone know of air flow test related to the "closed looking filters" that claim removal of everything.
thanks

[Lambo]

I don't have any brand specific advice to offer, but sizing is very important. You may not be able to just install "any filter that will fit" in your existing filter track. The furnace blower was designed to do a specific amount of work. The blower assembly most likely has a published "Fan Curve" chart associated with it. If the original ductwork and filter track were designed/installed properly, the blower should have enough power to account for the restrictions offered by ductwork, coils, filters, etc. and maintain the right pressure differentials. If you offer more restriction with high efficiency filters, you may affect the blower performance, which can lead to a multitude of other problems. The extended surface area of these filters usually accounts for their size in relation to the more restrictive materials used.
In some cases you may have to have your ductwork modified to accept certain filters.
You also stated that you had two filters. All air entering the air handler/furnace must be filtered, but there should be no occasions where the filters are in series with each other that I know of-----at least in residential applications. Parallel filters in individually filtered return ducts are fine----just more filters to keep up with.