Washable Furnace Filters
 

Anyone have experience with the washable furnace filters? Thinking about buying the one you simply hose off and reuse. My only concern is will this create a perfect situation for mold.

Personally, I prefer the throwaway type. They are cheap enough, and easy to replace. I buy the "Filterbuy" brand from Amazon, and change them every 6 months. Also, I have found that the MERV 11 filters, instead of the standard MERV 8, provide less dust in the house, and a quieter HVAC system.

Why would it create mold? The filter will dry like any wet material would dry and if the blower comes on and moves air through it then it will dry even faster.

I bought a washable filter some time ago (18 months maybe?). It has worked well for me with no sign of mold. I wash it every three months.

The only thing I am unsure of is how well it actually filters the air. With a paper filter in place for six months you can often see dirt buildup. Cleaning mine every three months I don't see that. I assume it is working well but I have no way to determine if that is actually the case. I know I do not have a lot of dust in the air and the evaporator is not dirty so maybe that's an indication that it is working well.

Washable Vs Disposable Air Filters: Understanding the Pros and Cons | HVAC.com

Amazon had standard cartridge filter for $22 last month. Not worth the hassle of using permanent for me.

Ask your HVAC contractor

Unlike a paper filter, the washable filter has nothing that the mold likes to eat! It typically pays for itself in 1 year.

I just read the Cons and there are several things that are incorrect.

Cons:
Time Commitment. After cleaning a reusable filter, you must let it dry for 20-30 minutes.

For the washable filters that are being sold in the villages, you shake out the excess water and put it back in while it's damp. No drying necessary.


Reduced Efficiency. Washable filters typically feature lower MERV ratings, making them less efficient at capturing smaller particles such as pollen and mold spores.

This is not correct for the washable filters being sold in the villages. They are rated MERV 8 which is what about 95% of Villages homes use.


Initial Cost: The upfront cost of washable filters is typically higher.

This is true but the return on investment is about 1 year.

Pro Tip: Our Air Conditioner service guy told us that after hosing off the filter to lay it down directly on top of the outside air conditioner for 20 minutes to dry.

You say you "Prefer" the disposable filters. Have you used the washable kind and found them lacking- or are you simply satisfied with your initial choice of disposable?

We have had washable ones for several years and happy with them.
Even get friendly reminders time to wash them.

I have not used the washable type. I guess that I am just too lazy to get out the hose and wash them when I can just pop it a new paper filter. Also, I really like the MERV 11 filters that I have been using.

blow
 

as long as not dirty or moldy I use a blower on mine. You can get them online

I’ve used them in previous homes with no problems. Suggestion: if you’re concerned about mold in damp filter after washing, keep an old disposable one to use for the time the permanent one is drying, or buy two to swap out.

Washable filter
 

I have had washable filter for 22 years. Same one! Just rinse both sides with garden hose, let dry (use paper filter till dry) and you are done
No mold if u let dry for a couple of hours in sun.

I had the washable filter in my prior home. Easy easy, put it in the dishwasher. Only problem - remembering to do it. Now I have the throwaways delivered every six months from Amazon. The arrival is my reminder that it’s time to change it.

If they are aluminium, I would not put them into the dishwasher. Aluminium gives off a black residue when washed in a dishwasher. I believe it is caused by the dishwasher detergent.

My parents had washable filters. It was my job to wash them. I would never buy a washable filter. It is far easier to replace the 4 inch thick paper filter every 6 or 12 months. These filters have a very high surface area, are long lasting, and MERV 11 means they are very efficient at catching dust.

I've been told by an ac installer that the dense air filters can sometimes reduce the efficiency of the ac. They can reduce the air output of the blower.

While potentially true, I have had no issues using the MERV 11 filters. These filters reduce both dust and noise in the house. No problem with air flow. I recommend them over the MERV 8 filters.

I buy a MERV 12 filter once a year at Lowes for $35. How long would it take me to start saving money by washing a filter monthly?

You will save money with washable filters, but you can probably also save money by buying the filters from Amazon instead of Lowes.

If you never replaced the filter then it would never save you money.

If you replaced the filter as recommended, every three months or so, then it would save money in the first year.

I don't recall what mine cost but I think it was in the neighborhood of $90. Given that, if you insist on replacing your $35 filter once per year then you would save money in the third year.


EDIT: I wash mine quarterly, not monthly.

This is correct with filters MERV 11 and above. Not the MERV 8 washable filters.

No issues with mine. Be sure to let the filter dry completely before putting it back in after washing. If in doubt about how dry, just run the furnace fan for an hour after you install.

IMO if reusable don’t let dust pass inside unit they probably work Ok? Look in squirrel cage see how dirty it is? that’s where fine dust going to build up. In older units merv 11s might reduce air flow and efficiency. I used merv 11s in my older unit and I could tell difference is flow and sound. I had to turn up fan. My older unit gone now and I just stick with carrier suit case filter yearly replacement. Costly but designed for my unit.

Merv 11 paper the best
 

Our filter is supposed to be changed annually. At best your washable filter is Merv 8 runs anywhere between 130-150 dollars and will lose efficiency over time. A Merv 11 paper filter 20x20x 4 is only $30 and is much more efficient.

To even consider a washable filter, ask yourself how long you plan on living in your home. Then calculate lost efficiency and the probability that it will end up in the trash sooner or later. Most have their ducts eventually cleaned anyway within 5 years?

The washable filter sold in the villages DOES NOT loose efficiency over time. However, a paper filter that is allowed to accumulate dust (etc.) WILL loose efficiency over time.

Here is an interesting Bob Villa article on air filters.

How Often to Change a Furnace Filter, Solved! - Bob Vila

Please explain.
Comparing two filters that are both MERV 8, similar in construction, and start off the same new condition.
As they both trap dirt, both become plugged. They have less room for air to flow, thus restricting air flow.
If the paper one is becoming more restrictive, that would imply that it is capturing more dust. What else would cause it be more restrictive?

It doesn't really work that way for many systems. Systems with an ECM motor in the air handler will continue to produce essentially the same CFM as the filter becomes loaded. ECM motors are programmed to provide a specific amount of air flow. Of course, this is up to a point. A filter can become so loaded that the ECM motor cannot compensate. If you have a 4" media filter and no outstanding sources of "stuff" in the air, annual filter changes should be fine.

I have been using MERV 11 paper filters for several years with no issues. They work better than MERV 8. I change them at least every 6 months. If I had pets, I would change them more often. I don't agree with leaving a filter in the unit for a year, even though some filter manufacturers say it can be done. Also, I am always skeptical when a technician provides advice that doesn't seem to be based on any personal experience or research. Any filter will restrict air flow, especially when it gets dirty. That is just how it works. If the filter is very dirty when you replace it, you are not replacing it often enough.

Flow controlled closed loop motor controls have nothing to do with the amount of stuff captured by either filter type. It only alters the blower speed to compensate for a plugged filter. That does not make the filter material any different.

Sounds like that reply is implying that the paper filter will capture more stuff (even with the same MERV rating), and the blower motor speed will need to be increased.

Still looking for a real answer to my question. Why will the paper filter become more restrictive to the washable one, given that both are MERV 8 and both are the same physical construction.

4” paper is fine
 

I agree. Even when I change my paper filter annually, I see little dirt or debris. A slight discoloration at best. It would be pointless to get a 4 inch thick washable filter.

Go back and reread my post. I never made any statement about filter material or in any way implied that a paper filter will capture more stuff.

I prefer the higher MERV rating of the filters I buy at Lowe’s.

When Munn's installed our new Carrier HVAC, it used MERV 11 filter
and recommended to change very 12 months.

Remember, those units don't run much for 6 months in the winter