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Default lowering output of furnace?

I have several rooms in my house that I don't have to use, so I close them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is what
I have (replaced last year):

http://216.122.22.11/FetchDocument.a...3-559b84978136

I see three burners inside. I can either pull out one of the burner, or use
the shut-off valve to reduce the gas supply. I imagine removing one burner
would be more efficient since the remaining two burners will operate at
their designed setting.

But I'm not so sure the blower speed can be change. I don't mind rewiring
anything if I know it can be done.


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Default lowering output of furnace?

in my opinion this is a very bad idea for too many safety reasons. if
you think you can economically and safely re-engineer the furnace
better than they already designed it for its 80% efficiency, i believe
you may be dangerously incorrect. it would make more sense to safely
replace the furnace again with a highest efficiency model with the
variable speed blower and whatever other options you desire. you will
want to do a payback analysis on your upgrade costs versus the energy
savings.
easier things to do instead: i would use insulation everywhere it may
be installed and zone thermostat controls for your ducts. and, be sure
your piped drinking water flow in winter does not require this crawl
space heat.
consult your hvac installer to explore any options of blower speeds
that may exist in the present furnace, and discuss heat anticipator
settings of zone thermostats.

peter wrote:
I have several rooms in my house that I don't have to use, so I close them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is what
I have (replaced last year):

http://216.122.22.11/FetchDocument.a...3-559b84978136

I see three burners inside. I can either pull out one of the burner, or use
the shut-off valve to reduce the gas supply. I imagine removing one burner
would be more efficient since the remaining two burners will operate at
their designed setting.

But I'm not so sure the blower speed can be change. I don't mind rewiring
anything if I know it can be done.


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Default lowering output of furnace?

Then you should have gotten a 2 stage furnace and a variable speed
blower.
For what you have consider insulating the ducts in the crawlspace.
Or just move to a smaller house or remove part of the house. Sounds
like your house is too big for your needs.

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Default lowering output of furnace?

I have a friend who went too big on his furnace A HVAC contractor can
downsize the output by elminating burners but he said it coist him some
efficency, at home resale time you will need to change it back.

probably better to upgrade homes insulaion!

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Default lowering output of furnace?


"I have several rooms in my house that I don't have to use, so I close
them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and
noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is
traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages
in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is
what
I have (replaced last year): "



Even if you could turn off part of the burner, how is that going to
solve a problem of the remaining registers being windy and noisey?
That is determined by the blower, not the temp of the air coming out.
If anything, it will only make it worse, because with reduced heat
output, the blower will run even longer.

And if you have leakages in the crawlspace, it would seem the solution
to that would be to fix them, not lower the output of the furnace.



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Default lowering output of furnace?


peter wrote:
I have several rooms in my house that I don't have to use, so I close them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is what
I have (replaced last year):

http://216.122.22.11/FetchDocument.a...3-559b84978136

I see three burners inside. I can either pull out one of the burner, or use
the shut-off valve to reduce the gas supply. I imagine removing one burner
would be more efficient since the remaining two burners will operate at
their designed setting.

But I'm not so sure the blower speed can be change. I don't mind rewiring
anything if I know it can be done.


You could change pulleys on blower/motor, but it'd probably be simpler
to identify
the registers that are, in effect, whistles and replace them. Assuming
that you're not
trying to force too much flow through them- too much fan/too few
register sq-ft.

Like, if your system had x registers with, say 20 ft/sec flow through
them, and you
now have x/3 of the same registers, you'd have wind tunnels. You don't
want to
radically reduce the discharge area, and maybe want to consult with
local experts.

One thing that might help right now, is to lower the fan-switch setting
on the
furnace, so the fan comes on at lower temp. (And shuts off at lower
temp also.) This
will reduce temp of ducting, obviously, and boost efficiency of unit.

Some registers I've seen tend to whistle when almost closed. You may
want to
open some up a bit. Or replace with quieter.

J

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Default lowering output of furnace?

Closing off rooms totally is not a good idea. You may be able to reduce the
heat that is let into the room but don't cut it off totally. The exterior
walls, ceiling and floor will get extra cold without the heat, humidity
produced in the house will still find its way into the rooms and condense on
the cold surfaces. This can cause moisture damage and moulds to grow on the
surfaces and inside the framing.


"peter" wrote in message
news:RoVch.3056$bW2.2906@trndny04...
I have several rooms in my house that I don't have to use, so I close them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and
noisy. I believe the reduction in air flow also increases the furnace
output temperature and therefore increases heat loss while the air is
traveling in the heating ducts in the crawlspace. Also air is lost due to
leakages in the heating ducts -- my crawlspace is warmer than outside by at
least 10 degrees.

Is it generally possible to lower the heat output of a furnace? This is
what I have (replaced last year):

http://216.122.22.11/FetchDocument.a...3-559b84978136

I see three burners inside. I can either pull out one of the burner, or
use the shut-off valve to reduce the gas supply. I imagine removing one
burner would be more efficient since the remaining two burners will
operate at their designed setting.

But I'm not so sure the blower speed can be change. I don't mind rewiring
anything if I know it can be done.




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Default lowering output of furnace?

On Mon, 04 Dec 2006 13:29:21 GMT, "peter" wrote:

I have several rooms in my house that I don't have to use, so I close them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is what
I have (replaced last year):

http://216.122.22.11/FetchDocument.a...3-559b84978136

I see three burners inside. I can either pull out one of the burner, or use
the shut-off valve to reduce the gas supply. I imagine removing one burner
would be more efficient since the remaining two burners will operate at
their designed setting.

But I'm not so sure the blower speed can be change. I don't mind rewiring
anything if I know it can be done.


it is not recommended to do this as it may cause condensation in the
unit. any heat/ac unit is designed for a certain air flow and btu
rating. reducing the air flow could also cause the unit to cycle on
it's high limit control which could cause much worse such as a cracked
heat exchanger.
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Default lowering output of furnace?


wrote in message
oups.com...

"I have several rooms in my house that I don't have to use, so I close
them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and
noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is
traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages
in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is
what
I have (replaced last year): "



Even if you could turn off part of the burner, how is that going to
solve a problem of the remaining registers being windy and noisey?
That is determined by the blower, not the temp of the air coming out.
If anything, it will only make it worse, because with reduced heat
output, the blower will run even longer.

And if you have leakages in the crawlspace, it would seem the solution
to that would be to fix them, not lower the output of the furnace.

Leaks in the crawlspace may be a good thing, if you live in cold climate
area it may be the only thing keeping your pipes from freezing down there on
one of those real cold winter days.


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Default lowering output of furnace?

On Mon, 04 Dec 2006 13:29:21 GMT, "peter" wrote:

I have several rooms in my house that I don't have to use, so I close them
off and shut off the heater registers in those rooms to save energy.
However, this causes the remaining registers to become very windy and noisy.
I believe the reduction in air flow also increases the furnace output
temperature and therefore increases heat loss while the air is traveling in
the heating ducts in the crawlspace. Also air is lost due to leakages in the
heating ducts -- my crawlspace is warmer than outside by at least 10
degrees.

Is it generally possible to lower the heat output of a furnace? This is what
I have (replaced last year):

http://216.122.22.11/FetchDocument.a...3-559b84978136

I see three burners inside. I can either pull out one of the burner, or use
the shut-off valve to reduce the gas supply. I imagine removing one burner
would be more efficient since the remaining two burners will operate at
their designed setting.

But I'm not so sure the blower speed can be change. I don't mind rewiring
anything if I know it can be done.



If you're willing to screw around with the furnace, you ought to
be willing to modify the ductwork.
If the furnace isn't short-cycling because you're not moving
enough air to keep it cooled down, AND if the noise you're
hearing is being generated at the grilles, you might be
able to reduce the noise just by stepping up a size and
using bigger grilles. Otherwise,
Add more duct and registers to the rooms you ARE using, to
make up for the amount of air that you're no longer moving through the
closed rooms.

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