Has anyone tried the “Washable Lifetime” HVAC filters?
Just noticed that one of the big box stores is now selling both MERV 8 and MERV 13 “Lifetime Washable” filters on their website (they are not on the shelf in my local store). The image for the MERV 13 makes it appear they are micro pleat. Theoretically more pleats = greater surface area = lower static pressure. However the only review for the MERV 13 indicates using it increased the “noise” of the HVAC which to me indicates it increased the static pressure. But that is only one data point and who knows; maybe that reviewers system is designed for no more than MERV 8 and they used MERV 13…Has anyone tried these?
I would love to find a filter that has a less detrimental environmental impact. I cringe every 3 months when I change the MERV 13 filters and throw the old ones in the garbage. Having a lower impact on my wallet would also be a welcome side effect.
One hesitation is the directions indicate you have to clean these filters with the company’s “Specifically engineered cleaner” which has some cost impact, but less than the cost of a filter. Online reviews of the cleaner indicate one bottle cleans a filter 2-3 times and there is no chemical smell. Wonder what is in that stuff? I hope once the cleaner solution dries on the filter it does not have the side effect of putting undesirable things into the air as it passes through the filters. The MSDS sheet warns against allowing the product to enter “surface water or drains.” Not really any way to avoid that if the filter cleaning procedure is to spray it with the cleaner, then run water through the filter. Link to MSDS: https://kandn.com/msds/99-0624(US).pdf
Anyone here have any additional information about either this HVAC filter or the associated cleaning solution?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Bump...anyone have any information or insight on these filters and/or the cleaning solution?
When I've used washable filters, I've always just washed them with regular water -- no cleaner needed. My guess is you can skip the cleaner here, but I've never used these specific washable filters.
There are two things you can do to cut down on your filter replacements:
1- Replace the filters based on backpressure, not their life in months on a calendar. Get a small range manometer (0.25-0.5 inches of water column or so), connect it across the filter box. Keep track of the reading. As the filter clogs up, the back pressure will increase, and the manometer will read a higher pressure differential across the filter. There is NO NEED to replace the filter UNTIL it has clogged enough to cause an excessive increase in pressure across it. This is what we do commercially to cut down on filter changes. Replacing filters on a schedule is not necassary if you are making actual measurements like this. If you have a pretty clean house (not much dust), you can probably significantly increase the filter change interval on your furnace.
2- Get thicker filters, which last longer. I use Aprilaire's system, which is about a 5" or so deep filter with lots of pleats. They recommend annual replacement, but I find (using my manometer), that I can often stretch that out to 2-3 years without any issues. The filters cost more, but they last much, much longer. They also don't really have a frame -- the frame is reuseable, so you're essentially only replacing the filter media itself, which helps to cut down on waste.
Note that as filters clog up, they actually do a better job of filtering the air, so replacing filters often does NOT make for "cleaner air". Monitoring the filter with a manometer is the best thing you can do to cut down on unecassary filter changes.
Bill
What a great comment. I’ve been wondering the same thing. My GC does not even have a clue what air filtration is and so they along with our HVAC sub missed the spec for 5” thick MERV-13… anyway filter box is being made now but I’m going to ask about the manometer.
Can you provide any more info about how to set up something like that to measure the back pressure?
That is a great suggestion. The setup is easy. It's just an air tube (rigid plastic or brass) that gets cemented into holes in the duct both upstream and downstream of the filter. The manometer has connections for two tubes. You get some flexible plastic hose of the right size and connect the manometer ports to the ones on your ducts. Simple. The challenge is finding a cheap used micromanometer.
I just use holes drilled in the duct on either side of the filter, and poke rubber tube in when I want to take a measurement. Some rubber stoppers plug the holes when not in use. To do a "proper" setup, you need to use the real sample tubes, that go in and bend away from the airflow, so that the moving air doesn't influence the reading. You can buy these from supply houses, or make them if you can do basic metal work.
Basic manometers aren't too difficult to find. I use a Magnehelic device similar to this:
https://www.ebay.com/itm/226396401006?_skw=magnehelic&epid=671886577&itmmeta=01JF2X74X9P0V3BQCRG1S1RPPN&hash=item34b646ed6e:g:3nkAAOSwqihnCqP6&itmprp=enc%3AAQAJAAAA0HoV3kP08IDx%2BKZ9MfhVJKmjKMpcaplFsYn8B47VF%2Fagi51EGXanIrBO8CYLqsHXmBU%2Flu1Dikdqh6exQ2BgegF5FKu4CsHy8ld4j0NWKd5%2B%2F%2BWuI7iFRzKGwxbY0g1zuxzDddunj0dEQ7AVC6wC0DKtZbf%2Fcl5n%2FYUSGSiCz8HJk5kK5wj3dFkmDNu3C4GrkJ7NQGzSBJVoA1XRzrJqoCbxLKGiCL2Sm3WzqDiVpx9%2Fpven0u1gHqUDRuydkahJXS6bpMSqRr6tiQrZ0DFCWNk%3D%7Ctkp%3ABk9SR-rOnN34ZA
They make a 0.5" WC model too that will also work. You just want something that will read a pressure range suitable for your application, which usually will top out around 0.3" WC or so. The 0.25" WC meter is great, the 0.5" WC meter will work too, but will have a more compressed scale over the range you're using, so you just get a bit less measurement resolution. For simple "watch the filter to known when to change" it applications, either works fine.
Bill