Washable Furnace Filters

[jaydee325]

I have a geothermal heat pump. The air filters are an odd size and pricey!

I ran across a filter in the size I need that is washable. Info says wash every 6 to 8 weeks and specifically mentions they are suitable for a geothermal heat pump.

Has anyone had experience with the washable furnace filters and what was your experiences?

 

[oosik]

I see that K&N makes washable/reuseable home air conditioning/etc filters. I've got K&N engine air filter and cabin air filter on my Power Wagon. I would expect that these two filters will last 10+ years with appropriate maintenance. K&N makes exceptionally good filters. I don't have a furnace so no experience there.

It might help if you mention the brand you are looking at ...........

 

[lman]

I've got a geothermal and buy filters online in a box containing 6. Cheaper that way. I only use 1 per year. I don't know anything about the washable filters.

 

[Roadworthy]

You don't specify a brand on the washable filters you found. I have used washable filters on a conventional electric furnace with no issues. I just rinse with a garden hose - good as new.

 

[5030]

K&N filters = dirty air.

 

[cqaigy2]

K&N filters = dirty air.

At least for a vehicle. Not sure about their furnace filters.

 

[spitter]

What about one of those elecronic filters.:drink:

 

[jaydee325]

Here is the filter I ran across. This is the exact size I need. Unfortunately, it is out of stock right now.

Again, any experience with this type of filter is what I'm looking for.

29-1/2 x 31-1/2 x 2 Geothermal Filter | 29.5x31.5x2 Waterfurnace Bryant Carrier

 

[s219]

I buy them in bulk, usually costs $12-20 each for my geo unit (which takes 28x28x1 filters) and lasts a year. Prior to that I was using two 14x28 (standard size) filters taped side by side, which is actually how the OEM filter was made and how many larger or custom filters are made. You might want to explore if you can construct the filter that way using something off-the-shelf.

The website furnacefilterwarehouse.com used to be a good source but I see they were bought by brookaire.com and I don't have experience buying from them.

 

[rswyan]

We have a washable filter on our gas, forced air furnace that is probably 20 years old which has held up and works well.

Not sure of the brand (has a blue label sticker with white lettering), has an aluminum frame with a couple different kinds of media in it.

Likely bought it from either Home Depot or Lowes.

I'd say that their cleaning directions are spot on - ours catches a lot of dirt and I was cautioned by a friend who is in HVAC that the one we have at least, passes less air than a typical, normal furnace filter, so you really don't want to let them get clogged up.

I suppose lack of airflow could cause the heat exchanger to overheat.

 

[KennyG]

I'd say that their cleaning directions are spot on - ours catches a lot of dirt and I was cautioned by a friend who is in HVAC that the one we have at least, passes less air than a typical, normal furnace filter, so you really don't want to let them get clogged up.

I suppose lack of airflow could cause the heat exchanger to overheat.

It's really more of a problem with A/C. Low air flow will cause the coil to freeze. I run high efficiency filters (the corregated filter material) in the winter but cheap fiberglass ones in the summer to avoid freeze up. Of course, it may be my systems isn't quite up to specs.

 

[5030]

At least for a vehicle. Not sure about their furnace filters.

Right on. Oiled Gauze don't trap anything smaller then pea gravel...

 

[rekees4300]

Has anyone had experience with the washable furnace filters and what was your experiences?

Yes I've been using a washable furnace filter for years. Clean it monthly using "Allergy Free Electrostatic Filter Cleaner'".

Allergy-Free Electrostatic Filter Cleaner Spray | National Allergy

 

[orezok]

What is the MERV rating on the washable filters? Anything less than a 10 is a rock catcher.

 

[rekees4300]

The correct MERV rating depends on several variables.

All about MERV ratings | FilterBuy

 

[jaxs]

I've overseen hands on and supervised hundreds of air conditioning systems. Never saw a washable filter that did a good job. For average conditions,I reccomend Merv 8 pleated filters. Where there's health issuse highr merv should be considered. Filter must fit to prevent air deturing around it. Big box stores can order sizes they don't keep in stock. High effeciency filters restricting air flow is a mis-guided myth and here's why.
Running a cheap fiberglass filter a few months will alow enough stuff through to collect on coils and restrict flow way more than any filter will. I've cleaned enough coils to know that. There's another option for odd size filters. Spun polyester that sells by the roll is about equivelent to merv 6 which is much better that fiberglass. Among other ways,a fair filter can be fashioned with 2x2 welded wire and cut to fit polyester. How can you tell if your filter is doing the job? There should not be any dust or lint on duct walls downstream of filter. If there's dust and lint on duct walls,you can bet there's plenty trapped on coils.

 

[cqaigy2]

I've overseen hands on and supervised hundreds of air conditioning systems. Never saw a washable filter that did a good job. For average conditions,I reccomend Merv 8 pleated filters. Where there's health issuse highr merv should be considered. Filter must fit to prevent air deturing around it. Big box stores can order sizes they don't keep in stock. High effeciency filters restricting air flow is a mis-guided myth and here's why.
Running a cheap fiberglass filter a few months will alow enough stuff through to collect on coils and restrict flow way more than any filter will. I've cleaned enough coils to know that. There's another option for odd size filters. Spun polyester that sells by the roll is about equivelent to merv 6 which is much better that fiberglass. Among other ways,a fair filter can be fashioned with 2x2 welded wire and cut to fit polyester. How can you tell if your filter is doing the job? There should not be any dust or lint on duct walls downstream of filter. If there's dust and lint on duct walls,you can bet there's plenty trapped on coils.

Seems like a reasonable observation. Interesting information of diying a filter.

 

[not2old]

My house has a Climate Master geothermal furnace with a washable filter. It's about 13 years old and I wash it once a year by blasting it with the hand held shower on full hot. It appears to be some sort of aluminum mesh about 2.5" thick with an aluminum frame. I don't know how well it filters but seems comparable to those cheap replaceable ones you mostly see. We have considered getting an electronic unit.

 

[kenmac]

It's really more of a problem with A/C. Low air flow will cause the coil to freeze. I run high efficiency filters (the corregated filter material) in the winter but cheap fiberglass ones in the summer to avoid freeze up. Of course, it may be my systems isn't quite up to specs.

Actually, It would cause issues on both ends.. As an example....If you have a 80,000 BTU gas furnace @3 tons of air flow.. The furnace is designed to return enough air across the HE, so as to not not let the HE get too hot.. Of course there are (or should be) limit switches that should cycle the furnace burners off, should it not be able to flow enough air across the HE.

I have seen filters so restrictive, that the furnace would only fun a few seconds, and shut down on one of the limits to keep the furnace from melting to the ground.

Of course, once that limit cools down, the cycle starts all over again.
Burners come on, fan comes on and tries to blow air across the HE. Due to filter restrictions, the limit switch pops, burners shut down again

If you're going to use a more restrictive return filter, You should check your air flow, and adjust accordingly .
Even if it means increasing the return duct size