I've got a curiousity question regarding the Honeywell VisionPro
thermostats. When you set them up, you have to select the type
of system. And you also have to set the number of cycles per
hour. They use that method instead of setting a temp differential
that turns the system on and off. That way of doing it raises
it's own questions, eg, what happens if it's only 55 outside and
it's set to 5 cycles an hour? Does it still fire up for 5 cycles of
just a minute or even less?

But here's the main question that has me stumped. They
recommend setting the cycles per hour to 5 for furnaces
of less than 90% efficiency and to 3 per hour for furnaces that
are 90+% efficiency. That seems backwards to me.
Older, 80% eff furnaces have fully open paths from combustion
air in right through to the chimney. Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.

So, why would you want the 80% furnace to cycle 5 times
an hour, but the 95% one to cycle only 3 times?

* Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. *Think heat exchanger mass.



I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

On Jan 25, 11:59*am, Mark wrote:
* Each time it turns off,

whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. *Think heat exchanger mass.

I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, *when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

Same with gas. I think heat pumps do it as well. One could argue
that there is some loss in heating the inside of the duct work back up
but not a lot.

Mark wrote:
Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.



Hi,
That is why blower turn off is delayed when set temperature is reached.
The amount of delay is adjustable on the furnace control board. Mine is
set at 90 seconds.

On Jan 25, 11:59*am, Mark wrote:
* Each time it turns off,

whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. *Think heat exchanger mass.

I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, *when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

It took 5 minutes for my old oil furnace fan would kick on, and vent
temperature would be
as high as 140 degrees, that's after I made the fan go faster. Before
I moved in an uncovered the two main
return vents, I think the furnace would just cycle with overtemp.

I don't have any idea on the OP's situation.

greg

On 1/25/2011 7:28 AM, wrote:
I've got a curiousity question regarding the Honeywell VisionPro
thermostats. When you set them up, you have to select the type
of system. And you also have to set the number of cycles per
hour. They use that method instead of setting a temp differential
that turns the system on and off. That way of doing it raises
it's own questions, eg, what happens if it's only 55 outside and
it's set to 5 cycles an hour? Does it still fire up for 5 cycles of
just a minute or even less?

But here's the main question that has me stumped. They
recommend setting the cycles per hour to 5 for furnaces
of less than 90% efficiency and to 3 per hour for furnaces that
are 90+% efficiency. That seems backwards to me.
Older, 80% eff furnaces have fully open paths from combustion
air in right through to the chimney. Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.

So, why would you want the 80% furnace to cycle 5 times
an hour, but the 95% one to cycle only 3 times?

I've got a HW visionpro and it just comes on when the room gets cool and
goes off when it hits the set point. I set it all up myself and didn't
see any such thing about "cycles per hour"

--
Steve Barker
remove the "not" from my address to email

On 1/25/2011 10:59 AM, Mark wrote:
Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.



I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

That's the way any furnace works. They never shut the blower off with
the exchanger hot.

--
Steve Barker
remove the "not" from my address to email

Steve Barker wrote:
On 1/25/2011 10:59 AM, Mark wrote:
Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.



I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

That's the way any furnace works. They never shut the blower off with
the exchanger hot.

Hi,
Cycle per hour setting is kinda safety feature. That's max. cycle
allowed. Also Honeywell suggests how to set it depending on system
you have.
Your 'stat is as smart or smarter than you, so don't worry. I have two
Vision Pro 6000 in use one at home and one out at my cabin. Since I
installed them, only thing I had to do was replacing batteries.
Ex-Honeyweller

On Jan 26, 2:49*pm, Tony Hwang wrote:
Steve Barker wrote:
On 1/25/2011 10:59 AM, Mark wrote:
Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.

I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

That's the way any furnace works. They never shut the blower off with
the exchanger hot.

Hi,
Cycle per hour setting is kinda safety feature. That's max. cycle
allowed. Also Honeywell suggests how to set it depending on system
you have.

It's not a safety feature, it's how many times an hour it cycles and
can be
set from 1 to 12. What does safety have to do with whether the system
comes on 3 times an hour or 6?



Your 'stat is as smart or smarter than you, so don't worry.

It's not a question of worrying. It's a curiousity question of why
they would recommend
cycling an 80% furnace 5 times, while a 90+% only 3 times an hour.




I have two
Vision Pro 6000 in use one at home and one out at my cabin. Since I
installed them, only thing I had to do was replacing batteries.
Ex-Honeyweller- Hide quoted text -

- Show quoted text -

On Jan 26, 1:28*pm, Steve Barker wrote:
On 1/25/2011 7:28 AM, wrote:





I've got a curiousity question regarding the Honeywell VisionPro
thermostats. * When you set them up, you have to select the type
of system. * And you also have to set the number of cycles per
hour. * They use that method instead of setting a temp differential
that turns the system on and off. * That way of doing it raises
it's own questions, eg, what happens if it's only 55 outside and
it's set to 5 cycles an hour? * Does it still fire up for 5 cycles of
just a minute or even less?

But here's the main question that has me stumped. * They
recommend setting the cycles per hour to 5 for furnaces
of less than 90% efficiency and to 3 per hour for furnaces that
are 90+% efficiency. * *That seems backwards to me.
Older, 80% eff furnaces have fully open paths from combustion
air in right through to the chimney. * Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. *Think heat exchanger mass.

So, why would you want the 80% furnace to cycle 5 times
an hour, but the 95% one to cycle only 3 times?

I've got a HW visionpro and it just comes on when the room gets cool and
goes off when it hits the set point. *I set it all up myself and didn't
see any such thing about "cycles per hour"

--
Steve Barker
remove the "not" from my address to email- Hide quoted text -

- Show quoted text -

Maybe not in yours, or maybe you didn't get into the installer
programming section.
Honeywell plays games of trying to keep the installer programming
secret. They
want the consumer to just have the "owner's manual", which only tells
you how
to get to the limited user programming menu. You
won't find the install manual for their better thermostats on their
website. They
think you should pay a plumber $100 to come out and change a bit that
controls
your HVAC for you. It really ****es me off, but they are a great
thermostat.

http://www.wmitechnologies.com/pdfs/vision-pro.pdf

On Jan 26, 1:29*pm, Steve Barker wrote:
On 1/25/2011 10:59 AM, Mark wrote:

* *Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. *Think heat exchanger mass.

I don't have the answers to your other questions but in my older (oil
fired hot air) furnace with a massive cast iron heat exchanger, *when
the burner shuts off, the air circulation blower remains on until the
heat exchanger is cooled down.

So most of the stored heat is recovered and NOT lost to the chimney.

Mark

That's the way any furnace works. *They never shut the blower off with
the exchanger hot.

--
Steve Barker
remove the "not" from my address to email

I uderstand that. But at whatever temp they do shut off, eg 85,
there is still some
residual heat left in it that goes into the basement, garage, up the
chimney, etc. On an
old 80% furnace, 5 mins after it shuts off, it's not unusual for it to
still feel warm
to the touch. You can't cool off all the heat exchanger mass in just
the extra min
or so the blower runs after the burner shuts off. Hence, it would
seem to me you'd
want to run it at least the same number of cycles an hour that you'd
run a newer
furnace. In the grand scheme of things, maybe it doesn't amount to
much energy,
but why the difference in cycles an hour then?

On 1/26/2011 5:23 PM, wrote:
On Jan 26, 1:28 pm, Steve wrote:
On 1/25/2011 7:28 AM, wrote:





I've got a curiousity question regarding the Honeywell VisionPro
thermostats. When you set them up, you have to select the type
of system. And you also have to set the number of cycles per
hour. They use that method instead of setting a temp differential
that turns the system on and off. That way of doing it raises
it's own questions, eg, what happens if it's only 55 outside and
it's set to 5 cycles an hour? Does it still fire up for 5 cycles of
just a minute or even less?

But here's the main question that has me stumped. They
recommend setting the cycles per hour to 5 for furnaces
of less than 90% efficiency and to 3 per hour for furnaces that
are 90+% efficiency. That seems backwards to me.
Older, 80% eff furnaces have fully open paths from combustion
air in right through to the chimney. Each time it turns off,
whatever heat remains in the furnace is lost mostly to the
chimney and I would think there would be more of it left in
the old furnace too. Think heat exchanger mass.

So, why would you want the 80% furnace to cycle 5 times
an hour, but the 95% one to cycle only 3 times?

I've got a HW visionpro and it just comes on when the room gets cool and
goes off when it hits the set point. I set it all up myself and didn't
see any such thing about "cycles per hour"

--
Steve Barker
remove the "not" from my address to email- Hide quoted text -

- Show quoted text -

Maybe not in yours, or maybe you didn't get into the installer
programming section.
Honeywell plays games of trying to keep the installer programming
secret. They
want the consumer to just have the "owner's manual", which only tells
you how
to get to the limited user programming menu. You
won't find the install manual for their better thermostats on their
website. They
think you should pay a plumber $100 to come out and change a bit that
controls
your HVAC for you. It really ****es me off, but they are a great
thermostat.

http://www.wmitechnologies.com/pdfs/vision-pro.pdf

I've got the entire manual. And have been through all 15 million
options in the installer setup.

--
Steve Barker
remove the "not" from my address to email