greetings, i just replaced an elderly neigborhs hammock style filter. i
bought a roll of filter material and cut it to size and i was wondering
if doubling up on the filter to add life to the filter would work
thanks cj

cj wrote:
greetings, i just replaced an elderly neigborhs hammock style filter.
i bought a roll of filter material and cut it to size and i was
wondering if doubling up on the filter to add life to the filter
would work thanks cj

That would actually make it clog up twice as fast. To make a filter last longer
you need more surface area. Making the filter twice as thick does not add any
surface area.

"cj" wrote in message
...
greetings, i just replaced an elderly neigborhs hammock style filter. i
bought a roll of filter material and cut it to size and i was wondering if
doubling up on the filter to add life to the filter would work
thanks cj

Well, lets see...
You have to change it when it gets dirty. Would putting a second filter
behind the first stop the first from getting dirty. No? Then why would
doubling up add life?

Does the manufacurer recommend doubling up, or is the blower designed for a
single layer? What do you think doubling the air resistance will do to your
system?

If you could double up by doubling the area (rather than thickness) you
would be on to something.

ok, single layer it is
thanks cj

cj wrote:
greetings, i just replaced an elderly neigborhs hammock style filter. i
bought a roll of filter material and cut it to size and i was wondering
if doubling up on the filter to add life to the filter would work
thanks cj

On Mon, 21 Nov 2005 16:46:23 GMT, "Rick Brandt"
wrote:


That would actually make it clog up twice as fast. To make a filter last longer
you need more surface area. Making the filter twice as thick does not add any
surface area.


Oh yes. Doubling the thickness does increase the filter surface area.
It also increases the air resistance to recirculating air and that may
reduce hot air reaching registers further away from the furnace. You
probably won't lose the total amount of heat output from the furnace.
I think having the filter clog faster might be a desirable result as
one can throw away a clogged filter and thereby permanently remove the
dust from the circulating air. In fact I think I will do this, cut
the hammock type filter to increase the regular filter's
effectiveness(?)