John Gilmer wrote:
"Edge" wrote in message
...
Anyone see the recent Ask This Old House show which featured a new
product for creating zones for forced air systems? It creates room by
room zones by inflating and deflating balloons in the duct work.
Anyone see who makes this product and have any experience with it?

Unless that compressor unit is multi-speed, you have to be careful about
"zoning" a system with only one compressor.

If you cut the air flow too much you can cause the coils to freeze.

Before you even think about this approach, buy some sigital thermoters and
stick them in the register outlets. You might want to make a hole in the
duct to measure the temperature of the air coming out of the "inside" coil.
Manually shut down (or reduce the flow) to rooms with a low cooling priority
and check the other thernometers to ensure the air is still on the right
side of 40F.

Since it takes hours for central air to "catch up" the manual approach may
well be "gud enuf" for the short term.

If the manual approach gives you the results you need and you are lazy,
THEN you can look into dampners (either rotating or "balloon.")



The same problem occurs with gas heating systems. I had a
little old lady who had shut the vents to some rooms and
she ran the the thermostat at 85 deg because she was cold
natured. This caused the high limit on the combustion chamber
to trip, shutting the whole system down.

TDD