Furnance filter replacement Question??

[joelriverside]

I have a Lennox electric, forced air, furnance that came with the 1970 house I bought a decade or so ago.

It has some odd-sized air filter, the number escapes me, but that never mattered much as it also came with two washable foam filters.

Well, as I have gotten older and the climate has warmed each winter due to global warming (NOT), I find myself less willing to wander outside in the snow, take off the form faucet cover, uncoil the frozen hose and run ice cold water over my hands while trying to get dish detergent to foam so I can wash the X%#@* foam filter each month.

So, I got the bright idea of buying the disposable filters in 20 X 20 X 1 size at my local hardware store for 79 cents and cutting them to size.

Works fine, but as I cut the darn thing, I find I lose track of the "flow direction" -- on the side of these filters they have an arrow with the word flow, which I assume means the filter is only supposed to be installed with one side UP. As I write this, I just realized I could probably use a sharpie to put red "X" on the up side and that would solve my problem....but since I am already so far along on this message.....

Does it REALLY matter which side goes up on these things? Each side look identical to me. For those who care, here is a pix from the filter maker's website:

[JoeSpareBedroom]

It's just dust you're washing off. Take the filter into the shower with you. What's the worst that could happen? Wet dust on your toes?

Yes, it matters.

[DerbyDad03]

I used to have a T-shirt that read:

Save water - Shower with a friend.

The same holds true for a foam furnace filter. If you're concerned about any debris going down the drain, put a piece of screen over it and clean it out when you're done.

[joelriverside]

Original poster here....I have two rottweilers and a cat. For some reason, a large percentage of the filter's "catch" is pet hair, which I don't particulary want down the drain. The suggestion of putting a screen on the drain is OK, I suppose, but honestly, I think the screen would clog pretty quickly leaving me ankle deep in wet cat and dog hair. LOL>

If the direction of install truly does matter, I guess the Sharpie route is the way to go.

[JoeSpareBedroom]

website:

I used to have a T-shirt that read:

Save water - Shower with a friend.

The same holds true for a foam furnace filter. If you're concerned about any debris going down the drain, put a piece of screen over it and clean it out when you're done.

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Or, carefully vacuum off the bulk of the dust/lint/hair, and finish the job in the shower.

[readandpostrosie]

Original poster here....I have two rottweilers and a cat. For some reason, a large percentage of the filter's "catch" is pet hair, which I don't particulary want down the drain. The suggestion of putting a screen on the drain is OK, I suppose, but honestly, I think the screen would clog pretty quickly leaving me ankle deep in wet cat and dog hair. LOL>

If the direction of install truly does matter, I guess the Sharpie route is the way to go.

go with the disposable filters and use your red sharpie.......................sounds the easiest!

[JoeSpareBedroom]

website:

Original poster here....I have two rottweilers and a cat. For some reason, a large percentage of the filter's "catch" is pet hair, which I don't particulary want down the drain. The suggestion of putting a screen on the drain is OK, I suppose, but honestly, I think the screen would clog pretty quickly leaving me ankle deep in wet cat and dog hair. LOL>

If the direction of install truly does matter, I guess the Sharpie route is the way to go.

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Vacuum the pets more often. Cats usually don't like it, but dogs are dumb, so you can do whatever you want with them and they just smile.

[Jim Redelfs]

The [take a shower with the filter] is a good suggestion, pet hair notwithstanding.

With adequate water flow, pet hair will go down the drain just fine. It's L-O-N-G hair that is a potential clogger for a drain. Long hair gets hung up across the crosshatch drain "strainer"/protector that is, ostensibly, to prevent the loss of shampoo bottle caps and the like. This type of clog is weeks or months in the making and is more-or-less easily removed using a large crochet hook (don't tell the crocheter) or stiff wire with hook on one end. The wad that is extracted may gag a maggot. Be prepared.

Cheap, 1-inch framed, non-pleated "filters" are barely better than NO filter at all.

No.

[Bob F]

Frequently, filters have a metal or plastic layer on one side to give them strength. They are designed to have the strength layer resist the movement of the filter element. The air should flow through the element then past the strength layer.