Just wondering if the circulation function in programmable thermostat
means that it will turn the fan on 100% of the time when the heat or
cooling is on + it will turn the fan on 35% of the time that when the
heat or cooling is not on.

Can anyone clarify this?

wrote in message
oups.com...
Just wondering if the circulation function in programmable thermostat
means that it will turn the fan on 100% of the time when the heat or
cooling is on + it will turn the fan on 35% of the time that when the
heat or cooling is not on.

Can anyone clarify this?

umm, Circulation Function may mean Fan Only to simply circulate
the air with no heating or coolin?

"Many residential HVAC systems use different fan speeds for the different
HVAC functions. For example, the fan speed is lowest for the circulation
function, higher for the heating function, and highest for the cooling
function."

lee_houston wrote:
"Many residential HVAC systems use different fan speeds for the different
HVAC functions. For example, the fan speed is lowest for the circulation
function, higher for the heating function, and highest for the cooling
function."

From the manual of the Honeywell 8000 Pro:

Programmable Portion says:

Circ - fan runs randomly approximately 35% of time. Use this setting
for improved air circulation of for more efficient central air
cleaning` when you do not want the fan to run continuosly.

Manual Overide Programmable Portion says:

Circ - overides fan schedule. Fan circulates randomly for approximately
35% of time until the auto position is selected.

Does 35% of the time mean when the system is not on cool or heat? I
would think the fan would run 100% of the time if any conditioning was
happening at all.

Just spoke with Honeywell.

Apparently, the random 35% running time of the fan is based on a
particular schedule. For instance, if heating and/or cooling has been
set for the wake period, and then fan has been set to run with the
system, the fan will be on 100% of the time while either heating or
cooling is on. If during the wake period, the heating or cooling stops
AND the conditioning period is less than 35% of total wake period, then
the fan will run for up to 35% of the wake period.

This cannot be that accurate as it will require some prediction on the
thermostat's part. But, I guess it can help to circulate air when the
conditining part is off.

Hope this helps someone out there.