Carrier The Infinity IdealComfort modulating gas furnace

[mike08054]

Read this in an advertisement:

“We utilized a throttling valve on the outlet side of a two-stage gas valve,” explained David Spaeth, product manager of heating products, Carrier. “The flow is regulated to 40-, 65-, and 100-percent rates to accomplish three stages of heat. Our patented technology then monitors the needs of the home as the unit cycles and adjusts its operation accordingly.”

How does the Carrier differ from the York and Rheem modulating furnaces? From what I've read, York has more stages and does all the decision making on the unit board where the Rheem also has more stages but handles the logic at the thermostat.

With three stages is this Carrier significantly better than a two stage Carrier? Is their logic at the system board or the thermostat.

[beenthere]

Carrier can be regulated by teh furnace board, or the Infinity control.

York by the furnace board only.

Rheem by the Rheem mod control( t stat), or a 2 stage stat makes it a 3 stage furnace, or a single stage stat makes it a 2 stage furnace.

[BaldLoonie]

With the 40% capacity, you can spend much more time with the furnace on providing quiet, gentle warmth. But I'd only get this furnace with the Infinity control. I don't believe that a board can do a better job deciding how to fire than a thermostat that knows the setpoint and the room temp.

[teeoff]

I am having the 60K BTU 58MVC furnace installed today, the price difference was very minimal compared to the 58UVB 2 stage.

[mike08054]

If you tried to run one of the furnace board driven units (york or carrier) without a specifically designed tstat, won't the tstat logic conflict with the furnace board logic when determining run/cycle times?

Am I correct in guessing that the Rheem and Carrier are best run with the manufacturers controller and the york is best run off of a single stage stat (even though that seems counter-intuitive)?

[twisterbret]

I am having the 60K BTU 58MVC furnace installed today, the price difference was very minimal compared to the 58UVB 2 stage.

Is there info on the Carrier website? Does Bryant have a 3 stage? I'm close to signing on a 2 stage 90I.

Thanks

Twisterbret

[teeoff]

The info is on this site;
http://www.commercial.carrier.com/wcs/proddesc_display/0,,CLI1_DIV41_ETI4926_PRD1541,00.html?SMSESSION=NO
I'm sure Bryant has the same furnace.

[BaldLoonie]

T, are you getting the Infinity control? I think having the 40% low fire will really be nice but I'd sure want the stat deciding what's needed not the board.

[teeoff]

Yes, I'm getting the whole package;
58MVC Furnace
25HNA6 Heat Pump
Infinity Zoning control with 2 zones
Infinity controller and Smart Sensor
HUMCCL Humidifier

The Infinity controller will also tie into our existing Honeywell HRV.

[ampulman]

With the 40% capacity, you can spend much more time with the furnace on providing quiet, gentle warmth. But I'd only get this furnace with the Infinity control. I don't believe that a board can do a better job deciding how to fire than a thermostat that knows the setpoint and the room temp.

Baldloonie: I read the advertising (link) and it was kind of vague as to how the furnace would 'modulate'. Any guesses?

What would the 'middle' stage be? I just went to the Carrier site and searched for 58MVC. Would you believe, "NOT FOUND".

AM

[teeoff]

I believe Carrier is using the term 'modulating' loosely, it is a 3 stage furnace, or 'step modulating' as they call it. On mine, the low stage is 22,000, the middle stage is 37,000, and high stage is 56,000.

[BaldLoonie]

The middle stage is 65% which is low on the 2 stage. With the board controlling it, it tries to guess at what fire is needed based on past cycles. The best control is with the Infinity/Evolution stat so the thing does what the house needs.

[teeoff]

Is there info on the Carrier website? Does Bryant have a 3 stage? I'm close to signing on a 2 stage 90I.

Thanks

Twisterbret

Here is a link to the Bryant version.
http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/pds355cav.060.01.pdf

[beenthere]

and the york is best run off of a single stage stat (even though that seems counter-intuitive)?

Yes, the York is designed to use a single stage thermostat.
The first 6 minutes will basically be at 40%, after that the board increases its firing rate based on its last run cycles.

[ampulman]

Yes, the York is designed to use a single stage thermostat.
The first 6 minutes will basically be at 40%, after that the board increases its firing rate based on its last run cycles.

After reading this thread, I became interested in the Affinity furnace.

I spoke to a gentleman in the Philadelphia regional office of York regarding the use of (other than York) thermostats, particularly the VP IAQ.

He stated that Honeywell TSs and particularly, the IAQ would work perfectly with an Affinity Mod furnace.

AM

[mike08054]

For heater control I'm sure they will all work fine in the sense that they'll function as a single stage stat. But I'm still confused/concerned that the CPH setting conflict with the york mod board logic. Set it to 5 and it cycles 5x, set to 3 and it cycles 3x, set to 2 cycles 2x. I'm curious if the (board determined) run times will vary if you eliminate the "intelligent" stat and just a simple single stage is used.

With the york mod don't you just end up with a fancy stat that doesn't control anything? I don't know about all VPro models but some don't have humidity control/display capabilities.

Also with the Mod (from what I'm reading) you don't really want to do setback programming. Although maybe this will be more useful during cooling season.

Does york have a stat that displays the current stage during a heat cycle? I'm pretty sure that this is what every consumer wants to see when they buy a mod furnace. It's the same as having a hybrid car. Owners really go crazy for the big display that tells them when the electric motor is on and how "efficient" the car is runnning.

I guess all I'm saying/wondering is that you can have the world's best stat but what does it do for a system where the logic is on the furnace board.

[ampulman]

...Also with the Mod (from what I'm reading) you don't really want to do setback programming. Although maybe this will be more useful during cooling season.



Why so? After a setback, it should ramp up (per time limits) to a higher output temp.

AM

[beenthere]

There isn't any thermostat that can show you what % of modulation the York mod is at.
York recomends a CPH of 6 for the mod.( We set them to 4) The York mod will NOT recover from a set back as quick as the Rheem mod. A thermostat with adaptive recovery will bring on the the York mod alittle sooner in order to recover by the time its set for.

[mike08054]

If york recommends CPH 6 then what is the gain from setting to 4. Is it to get longer run times?

[beenthere]

what is the gain from setting to 4. Is it to get longer run times?

Slightly longer run cycle during milder temps. And we had 1 complaint of cycling to often. :)

[mike08054]

Out of curiosity, I set it for 6CPH this weekend. I tracked the on/off cycle for an hour this morning. Philadelphia, PA outdoor temp ~35-40 degrees F. Thermostat has been set to 69 (hold) since the previous day. The stat clicked on every 10 minutes. Cycles were approx. 5 minutes on and 5 minutes off.

So I imagine I'm getting 6 cycles per hour, or 144 per day. 5 minutes on and off each cycle. There are no comfort issues, the temp stays a constant 69, never changes on the display.

Is this considered normal/acceptable operation? Our old furnace was 40 years old so I can really compare the new and old furnace.

[beenthere]

What furnace do you have.

At 6 CPH your temp will vary by only a few tenth of a degree.
5 minutes on is barely enough to get to steady state efficiency.

[docholiday]

I believe Carrier is using the term 'modulating' loosely, it is a 3 stage furnace, or 'step modulating' as they call it. On mine, the low stage is 22,000, the middle stage is 37,000, and high stage is 56,000.

They use alot of terms loosley.

[mike08054]

Coleman Echelon 9.C Modulating (FC9C080B12UP11)
Honeywell VisionPro 8000 (TH8110U1003)

The default for the thermostat was 5 CPH. At lower settings the run times are longer but the blower seems to ramp up a lot by the end of the run cycle and is very loud.

[jrbenny]

If blower is loud, it's a duct issue. Not a furnace issue.

[beenthere]

As JR said, if the blower is loud, it's a duct issue. Not a furnace issue.

For the first 6 minutes the furnace is at 40%. The temp rise can be set for 10* less then factory setting. That will kep it alittle queiter. But you might want to have the duct issues taken care of.

[mike08054]

Not sure if I have a duct problem, here's my reasoning:

The Continuous fan jumper has three positions. The "A" position delivers maximum airflow, 100% of the blower capacity. Position "B" delivers approximately 70% of the blower capacity. And Position "C" delivers minimum airflow, approximately 40% of the blower capacity

The default was "A" 100%. Very loud - sounds like a freight train

Set to "B" 70% the fan is noticeable in ducts closest to the furnace (rooms directly above) but not loud that we would consider it a problem.

Haven't tried "C" 40% but will try this but I expect it to be less noise than "B".

Seems like the continuous fan mode settings apply only when not in a heat cycle. When the stat was set at 6CPH and cycles were very short you couldn't hear the blower at all.

Setting CPH to 4 or lower the blower sounds louder than the "B" setting in continuous mode. I would reason that this means the blower is running higher than 70% during the heating cycle.

I will give it a few days for the stat/furnace to learn the house.

I don't understand what the temp rise setting is or where it can be set. I see that the york model has more custom configurations (jumpers/taps) on the board than the coleman model.
York: http://www.yorkupg.com/PDFFiles/271044-UUM-B-0707.pdf
Coleman: http://www.colemanac.com/PDFFiles/172079-UUM-C-0606.pdf

[tacoma]

Even on a 40 year old furnace I set at 70 and it heats to 70 do we really need to inprove comfort that much??I need 64,000 BTU to heat my house weather I put them in twice as fast or half as slow I still need the same number of BTUs

[beenthere]

Even on a 40 year old furnace I set at 70 and it heats to 70 do we really need to inprove comfort that much??I need 64,000 BTU to heat my house weather I put them in twice as fast or half as slow I still need the same number of BTUs

You only need those 64,000 BTU's an hour at design temp.
When it is 40 out side you need less, so the mod's and 2 stage units will run longer helping to prevent a people from feeling a draft from short cycles due to the reduced heating load.


Does anyone really need that kind of comfort? NO.

But no one really needs a Bentley either, but people still buy them.

[dash]

You only need those 64,000 BTU's an hour at design temp.
When it is 40 out side you need less, so the mod's and 2 stage units will run longer helping to prevent a people from feeling a draft from short cycles due to the reduced heating load.


Does anyone really need that kind of comfort? NO.

But no one really needs a Bentley either, but people still buy them.

They may not "Need" that much comfort,but after they experience it,they will always want it!!

[beenthere]

They may not "Need" that much comfort,but after they experience it,they will always want it!!
I agree.

[brentley]

They may not "Need" that much comfort,but after they experience it,they will always want it!!

I just had a 80k BTU unit installed with 2 zones in our house.
All I can say is wow. We replaced a single stage 100k oversized unit that has 2 zone dampers but only one was functional. We had serious challenges with turning the upstairs into an oven, while the downstairs remained cold.

This morning when my wife was in her office in the upstairs and it kicked on, then dropped to the low setting she was so excited (before it would just blow out 100k btu of heat into her office until the unit was turned off manually).

I am a converted believer, it wasn't cheap, but worth it.