Hi,
I've been in my house for a year, I looked inside all of the interior
air intakes for my central air system, and none of them seem to have a
filter. I was in the crawl space yesterday and saw what look like used
filters, left by prefvious owner. Do all Central air systems have
filters? If the filters is not in the intakes where are they? The
machinery of central air system is in the crawl space, is the filter
located in this part of the system? Thanks.

On May 12, 9:05 am, wrote:
Hi,
I've been in my house for a year, I looked inside all of the interior
air intakes for my central air system, and none of them seem to have a
filter. I was in the crawl space yesterday and saw what look like used
filters, left by prefvious owner. Do all Central air systems have
filters? If the filters is not in the intakes where are they? The
machinery of central air system is in the crawl space, is the filter
located in this part of the system? Thanks.

Mine is on the intake side of the air handler (squirrel cage fan), but
mine is an a closet in the house. Seem odd
that they would force going to the crawl space to change filters, but
who knows what the installer was thinking.
If you find it there and don't like that, you could always change out
the intake grills to ones that take filters, &
just leave the one in the unit out.

On May 12, 10:38*am, Eric in North TX wrote:
On May 12, 9:05 am, wrote:

Hi,
I've been in my house for a year, I looked inside all of the interior
air intakes for my central air system, and none of them seem to have a
filter. I was in the crawl space yesterday and saw what look like used
filters, left by prefvious owner. Do all Central air systems have
filters? If the filters is not in the intakes where are they? The
machinery of central air system is in the crawl space, is the filter
located in this part of the system? Thanks.

Mine is on the intake side of the air handler (squirrel cage fan), but
mine is an a closet in the house. Seem odd
that they would force going to the crawl space to change filters, but
who knows what the installer was thinking.
If you find it there and don't like that, you could always change out
the intake grills to ones that take filters, &
just leave the one in the unit out.

you could always change out the intake grills to ones that take
filters

Replacing the single filter with multiple filters at the intakes could
restrict air flow to the system making it work harder or be less
efficient.

The OP might want to get an on-site professional opinion before going
down that path.

If you've been there a year and don't know when the system was
inspected last, it might make sense to schedule a check-up. When you
call to make the appointment, tell them you want to talk about
changing the filter layout and that you want to make sure that they
send out a knowledgable service rep.

On May 12, 2:36*pm, "Joseph Meehan"
wrote:
"DerbyDad03" wrote in message

...

On May 12, 10:38 am, Eric in North TX wrote:
On May 12, 9:05 am, wrote:

...

you could always change out the intake grills to ones that take
filters

Replacing the single filter with multiple filters at the intakes could
restrict air flow to the system making it work harder or be less
efficient....

* * More likely it would reduce the restriction since it would be equivalent
to using a larger filter. *Just make sure the original filer is removed and
that any opening at that point is sealed.

What am I missing?

Let's say your system has a 20" x 20" opening (400 square inches) with
a single filter causing some amount of restriction. This restriction
could be measured on a per inch basis, determined by the filter
material.

In this same system, ahead of the single filter, you've got 10
intakes, all measuring 10" x 5" (500 square inches) unrestricted by
a filter.

Now you pull the single 400 square inch filter and replace it with ten
50 square inch filters, each of whom restrict the same amount of air
per square inch.

Haven't you restricted 100 additional square inches of opening - 500
instead of 400?



If you've been there a year and don't know when the system was
inspected last, it might make sense to schedule a check-up. When you
call to make the appointment, tell them you want to talk about
changing the filter layout and that you want to make sure that they
send out a knowledgable service rep.

--
Joseph Meehan

*Dia 's Muire duit

On Mon, 12 May 2008 07:05:00 -0700 (PDT),
wrote:

Hi,
I've been in my house for a year, I looked inside all of the interior
air intakes for my central air system, and none of them seem to have a
filter. I was in the crawl space yesterday and saw what look like used
filters, left by prefvious owner. Do all Central air systems have
filters? If the filters is not in the intakes where are they? The
machinery of central air system is in the crawl space, is the filter
located in this part of the system?

Yep, that's generally where the filter is located. It will be where
the intake air goes into the unit.

On May 12, 12:31*pm, DerbyDad03 wrote:
On May 12, 2:36*pm, "Joseph Meehan"
wrote:



"DerbyDad03" wrote in message

...

On May 12, 10:38 am, Eric in North TX wrote:
On May 12, 9:05 am, wrote:

...

you could always change out the intake grills to ones that take
filters

Replacing the single filter with multiple filters at the intakes could
restrict air flow to the system making it work harder or be less
efficient....

* * More likely it would reduce the restriction since it would be equivalent
to using a larger filter. *Just make sure the original filer is removed and
that any opening at that point is sealed.

What am I missing?

Let's say your system has a 20" x 20" opening (400 square inches) with
a single filter causing some amount of restriction. This restriction
could be measured on a per inch basis, determined by the filter
material.

In this same system, ahead of the single filter, you've got 10
intakes, all measuring 10" *x 5" *(500 square inches) unrestricted by
a filter.

Now you pull the single 400 square inch filter and replace it with ten
50 square inch filters, each of whom restrict the same amount of air
per square inch.

Haven't you restricted 100 additional square inches of opening - 500
instead of 400?



If you've been there a year and don't know when the system was
inspected last, it might make sense to schedule a check-up. When you
call to make the appointment, tell them you want to talk about
changing the filter layout and that you want to make sure that they
send out a knowledgable service rep.

--
Joseph Meehan

*Dia 's Muire duit

The pressure drop across each of the multiple intake filters is lower
than the pressure drop across the single filter.

Take the example to the extreme case.

Case one replace a single 20x20 with 10 ea 10x5's 400 sq in of
filter gets replaced by 500 sq in of filter

Case two replace the single 20x20 with 100ea 10x5 400 sq in of filter
gets replaced by 5000 sq in of filter

Now you're "restricting" 12x the area....will this help or choke off
the flow?

having a larger filter on your shop vac doesn't restrict the flow
more, a larger filter provides less restriction.
Tape over half of the filter....the vac will struggle.

Add a filter in parallel & the vac will not work as hard even though
you've "restricted" twice the area.

It's the concept of resistors in parallel.


cheers
Bob

On May 12, 12:31*pm, DerbyDad03 wrote:
On May 12, 2:36*pm, "Joseph Meehan"
wrote:



"DerbyDad03" wrote in message

...

On May 12, 10:38 am, Eric in North TX wrote:
On May 12, 9:05 am, wrote:

...

you could always change out the intake grills to ones that take
filters

Replacing the single filter with multiple filters at the intakes could
restrict air flow to the system making it work harder or be less
efficient....

* * More likely it would reduce the restriction since it would be equivalent
to using a larger filter. *Just make sure the original filer is removed and
that any opening at that point is sealed.

What am I missing?

Let's say your system has a 20" x 20" opening (400 square inches) with
a single filter causing some amount of restriction. This restriction
could be measured on a per inch basis, determined by the filter
material.

In this same system, ahead of the single filter, you've got 10
intakes, all measuring 10" *x 5" *(500 square inches) unrestricted by
a filter.

Now you pull the single 400 square inch filter and replace it with ten
50 square inch filters, each of whom restrict the same amount of air
per square inch.

Haven't you restricted 100 additional square inches of opening - 500
instead of 400?



If you've been there a year and don't know when the system was
inspected last, it might make sense to schedule a check-up. When you
call to make the appointment, tell them you want to talk about
changing the filter layout and that you want to make sure that they
send out a knowledgable service rep.

--
Joseph Meehan

*Dia 's Muire duit

The pressure drop across each of the multiple intake filters is lower
than the pressure drop across the single filter.

Take the example to the extreme case.

Case one replace a single 20x20 with 10 ea 10x5's 400 sq in of
filter gets replaced by 500 sq in of filter

Case two replace the single 20x20 with 100ea 10x5 400 sq in of filter
gets replaced by 5000 sq in of filter

Now you're "restricting" 12x the area....will this help or choke off
the flow?

having a larger filter on your shop vac doesn't restrict the flow
more, a larger filter provides less restriction.
Tape over half of the filter....the vac will struggle.

Add a filter in parallel & the vac will not work as hard even though
you've "restricted" twice the area.

It's the concept of resistors in parallel.


cheers
Bob

wrote in news:fec4bbe1-557e-4e1f-866c-
:

Hi,
I've been in my house for a year, I looked inside all of the interior
air intakes for my central air system, and none of them seem to have a
filter. I was in the crawl space yesterday and saw what look like used
filters, left by prefvious owner. Do all Central air systems have
filters? If the filters is not in the intakes where are they? The
machinery of central air system is in the crawl space, is the filter
located in this part of the system? Thanks.


SInce you went to the extreme of looking in the crawl space, I imagine you
looked hard here but...

....in one closet unit in an apt I saw it slid in a narrow slot like a card.
Once inserted, all you would see is one of the narrow edges.

Red Green wrote in message ...
wrote in news:fec4bbe1-557e-4e1f-866c-
:

Hi,
I've been in my house for a year, I looked inside all of the
interior
air intakes for my central air system, and none of them seem to
have a
filter. I was in the crawl space yesterday and saw what look like
used
filters, left by prefvious owner. Do all Central air systems have
filters? If the filters is not in the intakes where are they? The
machinery of central air system is in the crawl space, is the
filter
located in this part of the system? Thanks.


SInce you went to the extreme of looking in the crawl space, I
imagine you
looked hard here but...

...in one closet unit in an apt I saw it slid in a narrow slot like a
card.
Once inserted, all you would see is one of the narrow edges.

Mine is in the side of the unit and slides into a slot as you say. It
has a metal piece that slides down over the slot after the filter is
inserted, so it's hard to see. I looked for it for awhile before
finding it.

Cheri