Reusable filter OK?

[miket]

I have a Lennox CB31MV that takes 20" x 22 1/4" filters. I buy them on the net because I can't find them locally.

The ones I normally get are pleated MERV 8. I recently saw a washable MERV 5 filter and wonder if it would be suitable.

Thanks.

[Irascible]

Some IAQ hustler will inevitably contradict me 100%. But the lower grade filter is fine. Higher grade filters often do little for air quality. It depends on you environment and behavior. It takes a real commitment to actually improve air quality any significant amount. And if you're not worried about IAQ then don't worry about the machine. The washable filter will keep it happy unless you just happen to have a super dirty environment. Live behind a quarry? OK. In that case put in expensive filters.

[wyounger]

I agree with Irascible on the air quality comment. But be highly skeptical of washable filters; despite their claims, many of them are very restrictive of airflow through the system, which can cause inefficiency and equipment damage.

[Irascible]

U R right. I was thinking of "hog hair" type filters. The washable electrostatics are generally to be avoided unless the system is designed to handle the pressure drop.

[dash]

I've heard a "wet coil" is a Merv 5 or 6 filter.If you don't want the coil to be the best filtering device in the system,go Merv 8 or better.You'll likely save on coil cleaning costs in the future.


Signed.The IAQ Hustler!LOL

[Irascible]

Are you a duct cleaner Dash? I knew there was something wrong. Your love of the Carrier Kool-Aid wasn't enough to explain everything.

[dash]

No duct cleaning here.

[sean88]

Wash it and hit it with some hair spray. The hair will act as a tactant, i.e., it will grab dust/dirt as it goes by.

An old air balancer told me that trick.

[Irascible]

Originally posted by dash
No duct cleaning here.

Excellent. Then it's just a question of differing opinions (as opposed to arguing with the cognitively dissonant ).

[RoBoTeq]

I am also a fan of the hogs hair washable filters. As long as they fit tight and are supported with a few wires run through them they hold up well and don't allow air to pass around their perimeter.

I prefer having washable filters vacuumed unless they get really dirty where the dirt penetrates deep into the filter.

Either way, I have found that a properly fitting and supported hogs hair filter to be the most forgiving as far as not restricting the air while still trapping impurities from the air.

Hair spray is not a bad filter coating, but, filter coatings are really only needed on metal mesh type of filters. All filters made of any type of plastic/nylon material are in essence electrostatic and don't need to have a coating applied.

[dash]

Ira,

So do you think the filter should be able to catch particles smaller then the coil will,or just clean the coil more often?This is irregardless of what Merv ,you or I may think it takes ,for the filter to be superior to the wet coil in filtering ability.

[RoBoTeq]

I agree that the filter should catch any particulate that could be stopped by a wet coil. Since I has service contracts that included cleaning coils when needed, I did everything I could to keep those coils from getting dirty.

My cleanest coils were ones that the systems had properly fitting hogs hair filters installed in. This includes the ones that I had installed electronic air cleaners that I also kept up on. The hogs hair filters have very little resistance even when dirty.

[dash]

We find just about the opposite,pleated medias and EAC.s the coils are clean for years,if maintain/changed as needed .

The Carrier hogs hair standard are the worst,though nobody coats them with filter spray that I heard of.


With better filters there is also a lot less "stuff "growing in the pan,and drailine.

[miket]

Consensus seems to be reusable is OK. Should have given a little more background initially, but I live almost literally on top of a major road and my home is very dusty. Also, I'm in NJ, the system is a heat pump, and the coil will be dry most of the year, if it matters.

I get my filters from filtersolutions.com and was considering this. If someone has a recommendation for an alternate supplier that can make custom sizes, let me know.

Thanks to everyone who responded.

[RoBoTeq]

Doesn't really give you much info, does it?

I would go to a Home Depot and buy a couple of hogs hair filters. Just cut them to the size you need and maybe run a couple of stiff wires through them for support. I like leaving the edges raw so that the filter forms to the filter rack channel.

[Irascible]

Dash,

I would agree with what you said in theory. I'm forced to take your word for it that the evap coil filters the same as a hog hair.

But in practice I don't actually see what you're talking about. I've been a service man for ten years - NOT an installer for a few then a service man. I've done almost nothing but service so I see what these coils look like after years and years of cheap but changed regular filters. And the result is that the coil, furnace blower etc. are all fine nearly all of the time.

I don't actually resort to hog hair filters too often. I typically tell customers to buy disposable fiber glass filters. My experience with either is that most systems can go 20 years and never need their coils to be cleaned IF the filter is fitted correctly and changed regularly.

I'm certain their are regional differences to be considered. This is mostly urban and suburban land. Paved roads and manicured laws are the norm. In farm country and the back forty I might be singing a different tune.

[miket]

Follow up:

Finally spoke to my installer on an unrelated matter (the spot cooler/mini-split thread in the commercial forum). He strongly recommends against reusable because they don't maintain their effectiveness after repeated cleaning -- the coating doesn't last. So, I'm sticking with the disposables.

Thanks to everyone who replied.

[dash]

GOOD choice.IMHO.