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coloradotrout
 
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Default poor furnace/ac filter fit

My filter is on the inside of the blower box just ahead of the fan.
When the blower is running, it naturally tends to pull the filter
towards it. To hold the filter in place, two heavy guage wires wedged
into the upper left and right edge of the filter (and down against the
floor) and the bottom of the filter kinda/sortta sits in make-shift
ledge.

Seems to me a better design would be to relocate the filter outside
the blower box so it is pulled tight against the box when running.

But the area outside the opening to the box is 22" wide. The filter I
have now is 16x25, and the next smallest I see 16x20. That would mean
somehow making the opening smaller. and then what impact on airflow?

any other ideas?
  #2   Report Post  
coloradotrout
 
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Default poor furnace/ac filter fit

the real issue is that the 16x25 filter has to be bent to pry into
place. In so doing, I mess up the pleated filter and my theory is
that then the pleats are collapsing during operation and restricting
airflow significantly.

I really want a good filter to filter out some alergens, etc. Using
3m filtrete extra/ultra
  #3   Report Post  
-D
 
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Default poor furnace/ac filter fit

coloradotrout wrote:

the real issue is that the 16x25 filter has to be bent to pry into
place. In so doing, I mess up the pleated filter and my theory is
that then the pleats are collapsing during operation and restricting
airflow significantly.

I really want a good filter to filter out some alergens, etc. Using 3m filtrete extra/ultra


Find out what the water column pressure drop is across that filter and
post it here. Pleated filters can drop your airflow considerably.
There should be a simple way to hold that filter down. -D

--
http://www.udarrell.com/air-conditio...city-seer.html


  #4   Report Post  
George E. Cawthon
 
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Default poor furnace/ac filter fit



coloradotrout wrote:

My filter is on the inside of the blower box just ahead of the fan.
When the blower is running, it naturally tends to pull the filter
towards it. To hold the filter in place, two heavy guage wires wedged
into the upper left and right edge of the filter (and down against the
floor) and the bottom of the filter kinda/sortta sits in make-shift
ledge.

Seems to me a better design would be to relocate the filter outside
the blower box so it is pulled tight against the box when running.

But the area outside the opening to the box is 22" wide. The filter I
have now is 16x25, and the next smallest I see 16x20. That would mean
somehow making the opening smaller. and then what impact on airflow?

any other ideas?


I don't see what the problem is, that is exactly how my
former furnace worked. If you insist on changing it don get
stuck on having the filter lie flat. If you put the filter
at an angle you can use a much longer one and have much
better efficiency. Lots of systems are like that. In mine,
you slide the filter in vertically through a narrow tall
door, then let flop down until it hits the opposite wall and
it is at an angle of about 30 degrees. And, you don't get
stuck on having the filter perfectly sealed. The next time
the air comes around the particles are likely to get stuck
in the air filter, assuming that you change your filters at
reasonable intervals.
  #5   Report Post  
coloradotrout
 
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Default poor furnace/ac filter fit

simple is good

the simple way would have been for the original installer to THINK
(maybe that costs extra these days.. or could it be that there is a
shortage..mmm)

I would think that a pleated filter needs to fit flat. I have to cram
mine in.. and in the process fold it some. That results in the wires
coming off the pleats.. thus they are likely to fold under pressure
(literally).

Then to keep it in, I have to use those 2 wires to wedge up against
the top corners. (wire running from top left corner of filter to
bottom left corner of floor) The bottom does not fit flat.. as the
fan mount extends up to the air opening. So.. if you can visualize..

With it wedged in there.. it kinda works. But I cringe everytime I
put the cover back on! How hard would it have been to devise a ledge
for the filter to rest against. and a simple exterior access door?
Impossible I gather.

Any suggestions appreciated.




  #6   Report Post  
coloradotrout
 
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Default poor furnace/ac filter fit

the tilting idea is worthy; more surface area; that i need

i will have another look

The issue is my opening from return is right next to the blower unit.
I don't really have a way to tip the filter. It would tip against the
fan unit -- which -- I suppose could work, but just flopping there
loose.


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George E. Cawthon
 
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Default poor furnace/ac filter fit



coloradotrout wrote:

the tilting idea is worthy; more surface area; that i need

i will have another look

The issue is my opening from return is right next to the blower unit.
I don't really have a way to tip the filter. It would tip against the
fan unit -- which -- I suppose could work, but just flopping there
loose.


I can visualize that. Do you have a downdraft and where is
the furnace?
If you have some space another option is to use two filter
held in a V, lots more filter in less space, but may be hard
to fabricate.

Another thought if you don't have enough space above the
blower is to simply put the filters in the cold air
returns. That would be practical and easy to fabricate if
you have 4 or less (and way more efficient for air
passage). Could be a real hassel if you have returns in
every room.
  #8   Report Post  
coloradotrout
 
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Default poor furnace/ac filter fit

like those thoughts..

the "v" idea.. mmmm.. will have to think about that

i thought about moving the filter to a different spot in the cold air
return flow. furnace is in basement, but there are two bsmt return
vents plugged in right next to the furnace (so I cannot tap in after
those since they are so low in the return air channel).

I have 2 returns upstairs and 2 downstairs. I think it would be good
if I did have a return in each of the upstairs BRs (3), so that is
something I'm looking at doing. That does kinda make the idea of
filter at each vent a challenge.

Upstairs I have one return high up the wall in our vaulted room (good
for AC) and one in the hallway. Downstairs there is one between the
furnace room and the open finished area outside the furnace. And
there is one in a BR that backs up to the furnace room.

The trick is my return air run (what is it really called?) is 23"
wide, which gives about 22.5" inside, so the filter closest is 20" as
the 24" is too big.

I have a 3" W x 1/2" H galv. metal piece underneath my blower fan.
Not sure if it is supporting the blower; though I see the blower
attachd from above also. That chunk of metal extends over to the
return air inlet, which creates a "bump" that the filter must span.
If I get rid of that, then I have a smoother 16" x 25" area that the
filter can be placed against. There's still no "frame" for it to rest
against.. as it's in the blower box area. There's about 3" between
the return inlet and the fan housing. I might be able to somehow
fabricate a chunk of sheeting and screw it into place to create a
filter "slot".

For returns.. how do I know where, how many, and how large to place? I
have 32x10 in the hallway and one on the wall of our only vaulted
ceiling room. (ranch home w/ full bsmt) But w/o returns in the 3
BRs, they don't regulate well.
  #9   Report Post  
CBHvac
 
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Default poor furnace/ac filter fit


"coloradotrout" wrote in message
...
My filter is on the inside of the blower box just ahead of the fan.
When the blower is running, it naturally tends to pull the filter
towards it. To hold the filter in place, two heavy guage wires wedged
into the upper left and right edge of the filter (and down against the
floor) and the bottom of the filter kinda/sortta sits in make-shift
ledge.

Seems to me a better design would be to relocate the filter outside
the blower box so it is pulled tight against the box when running.

But the area outside the opening to the box is 22" wide. The filter I
have now is 16x25, and the next smallest I see 16x20. That would mean
somehow making the opening smaller. and then what impact on airflow?

any other ideas?


How about in all seriousness you get the right filter for it?

22X22X1 is a common size...you didnt say how deep it was...so ...left in the
dark there....but, I have yet to see a unit that a filter could not be had
for.


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coloradotrout
 
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Default poor furnace/ac filter fit

The opening between return air and blower box is about 16x22 (the
filter that was jammed in there is a 16x25)

There's really no room to create a larger opening, unless I go w/ the
tipping idea, but that's tricky also (really no room to tip)

Now thinking of creating a "slot" for the filter by somehow installing
a vertical "frame" just inside the blower box which will support the
filter btwn the blower box and the incoming return. I'll need to cut
away a tab of the blower box, and and cut a frame out of tin and
fasten somehow. It can work, but I'm still w/ a 16x25 filter.. and
the idea of more surface area would be great.

With no filter, I get very noticeable AIR from the vents throughout
the house. With the filter, it's not nearly as noticeable.


  #11   Report Post  
coloradotrout
 
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Default poor furnace/ac filter fit

since I don't know what Manual D is.. I'm 99% sure they did NOT.

Explain.. and I'll press them.

They did not install the furnace nor ductwork.. just the AC. But the
"comfort specialist" said the ducting was adequate.
  #12   Report Post  
CBHvac
 
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Default poor furnace/ac filter fit

A manual D, is the ACCA guide to insuring that the ductwork is of the
correct size, to insure not only correct BTU delivery to each room, but to
insure correct sizing of duct to make sure that CFM and velocity are
wtihing the correct guidelines for the unit in question.
It also takes into consideration, filter area, and all items in the
airstream, to maintain the correct static pressure for the unit to operate
correctly.


"coloradotrout" wrote in message
...
since I don't know what Manual D is.. I'm 99% sure they did NOT.

Explain.. and I'll press them.

They did not install the furnace nor ductwork.. just the AC. But the
"comfort specialist" said the ducting was adequate.



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