Home HVAC Filters

Oh, great knowers of all...

I purchased this home 8 months ago.
2 heat pumps outside with two "furnace/blower" assemblies in the crawl space. The needed filters are 16x25x4. Each unit needs its own filter so I need two.

What amazes me is that the cardboard and fabric filters are $20-$35 each! This leads me to wonder. 16x25x1 filters are $2-$4 each. Could 4 be used together to replicate one 4" filter without detrimental effects?

Any great resources for savings on these filters that I would like to change at least twice per year?
As it stands now I could be spending $100+ per year in filters!

I just use the ones that 4 for $3 and replace them once a month.

It really depends on the velocity of the air coming through the filter, which of course depends on cfm. I believe recommended velocity through the filter should be 300-350 fpm--lower is better. Presumably a 4" pleated filter would offer more filter area and less resistance to airflow than a thinner filter, and certainly less resistance than a lesser filter stacked. If you stack 4 filters you are going to impede airflow, and when they load up, they might just get sucked right out of the filter frame. Modify the frame and run a single 1" filter.

http://www.airfiltersdelivered.com/store/grid1.php?id=41625

I've used them for a funky size required for my AC that I can't find locally.

I wish I could get a bigger filter on mine. I've got 16-25-1. No way to improve it without a major re-working. Wish I had known better when I put it all together.

We bought our last set of 20x25x3's from Amazon.com

In reply to jrw1621:

I'd say buy a washable one, but most of the ones I've seen are only available in 1".

And, I'd recommend against using anything but the right size, but considering the number of times my cousin and I cut down larger filters after installing a unit my recommendation is kinda pointless.

Mine is 20x20x1. I've used everything from the cheapest crap filters all the way to the top of the line allergy catching bend over and pay $20 each filters, and still my house is the dustiest place on earth. At least I can get cheap filters in 20x20x1

What is with all this 3" stuff? Never heard of it. Won't fit mine anyway.

I used to work a a place that made washable lifetime filters. We would make a lot of custom sizes, I'm sure there have to be multiple companies doing that nowadays.

I would double check the service life of the filter, the heat pump in the house I am renting is 1x per year. I think I would shop online and maybe try to save a few $$$ but put in the right filter.

Amazon was the cheapest I found, but it wound up not being much different than my local HVAC supplier.

Gearheadotaku wrote: I wish I could get a bigger filter on mine. I've got 16-25-1. No way to improve it without a major re-working. Wish I had known better when I put it all together.

I think the price of the filter vs change interval is a wash anyway. I intentionally (HVAC guys at work recommended) went with the 16x25x1 and buy 3m filtrete multi packs.