HVAC filters too tight
Christopher Glaeser
However, the fit is extremely tight, and I have to crush the cardboard
filter somewhat to force fit it into the opening. It seems like the opening
is 1/16" too small or of the filter is 1/16" too big. Is this a common
problem? Are some brands of filters slightly smaller?
Best,
Christopher
harry
Gone metric I expect. Common problem.
ransley
I guess someone sometime bent the metal, maybe use a peice of wood to
get it the right size
Smitty Two
"Christopher Glaeser" <nos...@nospam.com> wrote:
We had that problem at the old shop. It came down to the installer being
an incompetent hack.
jamesgangnc
Try a scrap of wood and a hammer. You may be able to enlarge it a
little.
ransley
if wood doesnt work Vige Grips come in wide versions for metal holding
while welding , I used to have a pair of 6" wide ones, most any big
hardware store should have them but a peice of wood hammered right
should fix it and maybe use pliers. you need the filter tight so no
dirty air bypasses it.
Steve B
"Christopher Glaeser" <nos...@nospam.com> wrote in message
news:LKGdnb27RZQMxJ7R...@giganews.com...
The answer is yes, no, absolutely, maybe, and I don't know.
I just had the same problem with some 20 x 25's. They fit two abreast. I
got the medium grade ones, and they are a little flimsy. I turn on the air
to get suction to hold them in place for placement. When I did that, the
air sucked them inward so much it collapsed them. I had to run two wires
along the middle edges to keep them from collapsing inward. Some of the
filters fit great, others seem inconsistent in size.
But! One of the big deals is that the frame is held on with 1/4" head
screws and the heads sticks out and contact the outer edge of the filter.
Those types of fasteners are very common to HVAC sheet metal people. So, I
removed them and put common drywall screws so that it would not stick out,
and that they could be tightened a bit to suck that portion of the frame
outward and make more room.
It could be the screws, maybe the opening is a little out of square, or just
badly produced screens. I am going to have to do the wire thing with all my
returns (four) so that as the filters age a little, and the pressure builds
up, they are not sucked up. And that is made worse by any crimping in that
flimsy outer cardboard frame.
I'd change those screws, and perhaps add a couple of wires for strength.
But the wires MUST be far enough inside that they don't hold the face of the
filter out.
HTH
Steve
visit my blog at http://cabgbypasssurgery.com watch for the book
A fool shows his annoyance at once, but a prudent man overlooks an insult.
Christopher Glaeser
I'm the original owner of this home that was built ten years ago. There are
two 14x24 returns, and they are both undersized for the 14x24 3M filters.
It appears the framing was constructed from a long piece of sheet metal.
> maybe use a peice of wood to get it the right size
I don't think I can make the hole bigger using wood and a malet because
three of the corners are bends, so making the hole bigger would reguire
"stretching" the lengths of sheet metal. I'm guesing the only solution
(other than crushing the filter) would be to replace the current framing
with new framing.
Best,
Christopher
Christopher Glaeser
> screws and the heads sticks out and contact the outer edge of the filter.
The returns do have the 1/4" head screws, but are recessed about 3/4" from
the outer edge of the framing. The cardboard filters won't even clear the
framing until they have been crushed a bit.
It's been ten years, but I think the original filters installed when the
home was new were those cheap pieces of fiberglass cut to size and stuffed
into the hole.
Best,
Christopher
Steve B
If the hole is just too small, that would be your option. Before you do all
that, take out the sheetmetalwork, and cut it in half at one corner.
Reinstall with it tight in the two remaining corners, and just make it fit
as tight as you can. Maybe use something like a screw jack in the opening
to stretch it. You probably only need an eighth to a quarter inch.
Christopher Glaeser
> with it tight in the two remaining corners, and just make it fit as tight
> as you can.
Yeah, I think that would work. Thanks for the suggestion.
Best,
Christopher
Erma1ina
I encountered the same problem with the Filtrete filters (16x25) a year
or two ago. I had been using the same Filtretes for several years
without a problem.
I believe 3M uses various sources for manufacturing the filters. The
actual (not NOMINAL and not the "actual"-as-printed-on-the-filter)
thickness of the filters changed. I measured an old one which had worked
fine and a new one that was approx 1 mm thicker. Both the old and the
new had an "actual" thickness of 2 cm. printed on the filter.
I spoke with a 3M customer service person who claimed he "checked with
the lab" and there had been no change in specs and no reported problems.
I told him all he had to do was measure the thickness and compare it to
the specs printed on the filter itself.
I think many furnace installations have a lot of play in the filter
frame; mine doesn't and it sounds like yours doesn't either -- which is
great, as long as the filter manufacturers produce filters with actual
dimensions as specified.
I stopped using Filtretes.
Christopher Glaeser
Perhaps I should switch to reusables. I see some online that can be ordered
with tolerances of 1/8". Any comments, opinions, or recommendations for
reusables?
Best,
Christopher
Ron
Reusable filters are junk.....IMO
I buy "DP Max" filters from here http://www.airguard.com
12 for $50.00. (14x20)
Their filters are actually 1/2" smaller in length and width. So that
would solve your problem. IOW, my 14x20's are actually 13 1/2x19 1/2.
Steve B
I used them for about four years. They are difficult to get clean. Very
difficult. They are mostly expensive, some VERY expensive. The size micron
particles they trap is not that small. You can put sprays on there like
Lysol that help catch particles, and provide some degree of disinfectant,
but I hate the smell of Lysol or similar products from diving days when we
used it in our helmets and decompression chambers.
I like the midgrade waffle shaped ones with a lot of wire to keep them from
caving in. The paper ones, not the snaky thread kind.
Steve
visit my blog at http://cabgbypasssurgery.com
A fool shows his annoyance at once, but a prudent man overlooks an insult.
Steve B
"Ron" <BigEL...@msn.com> wrote in message
news:e627b8c2-8753-417a...@y21g2000vba.googlegroups.com...
Reusable filters are junk.....IMO
12 for $50.00. (14x20)
Thanks for the link. I may try a pack on my rentals. They cost about what
they do at the borg.
rnan...@gmail.com
Tekkie®
>
> I have historically bought 3M products anytime they are available because
of their historical quality. I use the same filter and it actually is the
same size. I have 4 of them in my house. The 3M Filtrate filters have
always been too large. I use a putty knife to slip behind the filters to
help work it into the opening sort of as you would use a shoe horn. I also
have one 14 X 14 return vent and the Filterate filer is equally oversized
for it. I've tried different brands with mixed results. There is a
difference in the exact sizes of filters from brand to brand. Some are too
small which allows the filter to move around enough to even bang up and
down on ceiling mounted filters as the HVAC cycles on and off. Very
Im not sure if any significant amount of air is getting buy unfiltered. The
biggest issue is that my filters are 12 to 16 feet above floor height. 3M
filters create a dangerous situation to have to work with both hands and get
beside or above them to get them in. We shouldn't have to set up
scaffolding or deform our frames to change the filters because 3M cant keep
their tolerances with an acceptable range. It also could be that 3M is
trying to use the same filer for metric and SAE filters.
--
Tekkie
Al
--
For full context, visit https://www.homeownershub.com/maintenance/hvac-filters-too-tight-444651-.htm
Ed Pawlowski
> I just had this same issue with the 3M Filtrete Filters. I had to
> wrestle with them - bending the edges both lengthwise and in the width,
> causing them to be a little deformed and convex to fit our 24 by 14
> sheet metal opening. I had ACE Hardware filters in before and they fit
> perfectly. I ordered Filtrete online because I thought they'd be a
> higher quality - filter as well or better and not cause excessive
> airflow restriction. However, this process of putting them in our
> ceilings was awful and I'm dreading fighting to get them out in 3 months
> when they're all filled with dust etc. Really surprised 3M hasn't fixed
> this problem!!! I see the original post was from 10 years ago.
>
I use Filtrete and they fit on the loose side.
gfre...@aol.com
<3a97c5dd3229a13f...@example.com> wrote:
>I just had this same issue with the 3M Filtrete Filters. I had to wrestle with them - bending the edges both lengthwise and in the width, causing them to be a little deformed and convex to fit our 24 by 14 sheet metal opening. I had ACE Hardware filters in before and they fit perfectly. I ordered Filtrete online because I thought they'd be a higher quality - filter as well or better and not cause excessive airflow restriction. However, this process of putting them in our ceilings was awful and I'm dreading fighting to get them out in 3 months when they're all filled with dust etc. Really surprised 3M hasn't fixed this problem!!! I see the original post was from 10 years ago.
them.
Bob F
> I just had this same issue with the 3M Filtrete Filters. I had to
> wrestle with them - bending the edges both lengthwise and in the width,
> causing them to be a little deformed and convex to fit our 24 by 14
> sheet metal opening. I had ACE Hardware filters in before and they fit
> perfectly. I ordered Filtrete online because I thought they'd be a
> higher quality - filter as well or better and not cause excessive
> airflow restriction. However, this process of putting them in our
> ceilings was awful and I'm dreading fighting to get them out in 3 months
> when they're all filled with dust etc. Really surprised 3M hasn't fixed
> this problem!!! I see the original post was from 10 years ago.
>
measurements. The "filter size" can be a significant fraction of an inch
different than the actual measurements.