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.