Carrier system questions

[letzleta]

I recently purchased a home (~2500 sq feet) with the following setup:
Furnace - Carrier 58MTB
AC - Carrier 24APA
Thermostat - Carrier Edge TP-PAC01

I have a few questions relating to this setup and the addition of a humidifier.

It is my understanding that the 58MTB is a 2 stage furnace, however the TP-PAC01 is a single stage thermostat. Would I see any benefit from switching to a TP-PRH which has the ability to control the 2 stage furnace?

Secondly, I am purchasing an aprilaire 700A humidifier. If I switch to the TP-PRH mentioned above, it also has the ability to control the humidifier. Is there any benefit to utilizing the thermostat to control the humidifier rather than the controller that comes with the unit?

Last, If I do not switch thermostats, the current thermostat has an outdoor temperature sensor. The humidifier requires and outdoor temp sensor to run in automatic mode. Can I wire the humidifier to the existing outdoor temperature sensor or do I have to install the one that comes with the new unit?

Apologies for the mismash of questions, I tried to lay them out in a logical manner but I am not sure that is possible. If more information is required, please let me know.

[letzleta]

I would ask the original installation company these questions, however, I am not confident that they would give me an unbiased answer. I came here to get opinions from the community before hiring someone to do the work so I know exactly how to request it be setup. Can anyone make suggestions?

The last HVAC work I had done was on my old house, they installed a humidifier and used a pin valve. From what I have read here, that is not the best way to install it. Knowing is half the battle.

[skippedover]

I'd highly recommend a full 2-stage t-stat with a 2-stage furnace. Absent a 2-stage stat, the furnace runs on a timer. Once a call for heat is initiated by the stat, the furnace runs for 10-minutes in an attempt to satisfy the stat. If it does, the furnace turns off. If not, it ramps up to 2nd stage, satisfies the stat and then turns off. When a 2-stage stat is used, it can run all day long on 1st stage as long as it never reaches set-point. As to the humidifier, I could go on a long dissertation regarding the needs and operation of one but I'd probably bore you to tears. So suffice it to say that a t-stat with a humidifier function attached serves the purpose of bringing on the furnace blower in the absence of a call for heat when additional humidification is needed. And chances are great that if you need humidity at all, the outdoor sensor with the humidifier is a great idea but will have precious little effect on how much moisture you'll need to put into the air. In that case, I'd recommend you put the included jumper on the humidifier control board to eliminate/override the outdoor sensor and you'll be all set.

[letzleta]

Thank you skippedover! That makes perfect sense.

That leads me to a few more questions.
1. My furnace seems to cycle on-off a lot (just my opinion). I need to actually time it. I know this would vary wildly based on a number of factors but is there a on-off cycle time that is standard (or a short cycle time that might be considered harmful to the unit)?

2. In my old home, my furnace had a variable speed blower which I left on all the time. When there was a call for heat, the blower would ramp up to full speed after the burners were running for a short time. With the 58MTB in my new home, I have the fan running on a low speed (there are 3 or 4 speeds I believe) but when there is a call for heat, the fan shuts off while the burners heat up. Is this an issue? Am I better off turning the fan to auto?

3. If I understand correctly, you are saying to run the humidifier in "manual" mode. Meaning set a RH%, ignoring the automated outdoor temp stuff. The included jumper you mention would be used if the humidifier is attached to the supplied control, but if its controlled from the t-stat will that jumper still be necessary? I believe the t-stat has its own "automatic" or "manual" setting (similar to the aprilaire controller).

[letzleta]

Also, to add to the previous post:

4. The Carrier TP-PRH I mentioned is quite expensive and the only reason I lean towards it is because the furnace and a/c are the same brand. Should I consider other t-stats with humidity controls? If so, what is reccomended? The Pro1 IAQ seems to be highly regarded on this forum and significantly less expensive.

5. With a 2 stage t-stat, when does it utilize the second heat stage? Will I potentially see a decrease in energy cost vs a 1 stage t-stat (again I realize actual results may vary)?

[skippedover]

Thank you skippedover! That makes perfect sense.

That leads me to a few more questions.
1. My furnace seems to cycle on-off a lot (just my opinion). I need to actually time it. I know this would vary wildly based on a number of factors but is there a on-off cycle time that is standard (or a short cycle time that might be considered harmful to the unit)?

There is no 'standard' cycle time. However, if you have a 2-stage unit, see my first response regarding length of runs on first stage. Even if your furnace runs for 11 minutes on a 1-stage t-stat, it may run 15 or 20 minutes if 2nd stage isn't called on just because a certain time elapses. Longer run times are both better for the furnace and better for your comfort.

2. In my old home, my furnace had a variable speed blower which I left on all the time. When there was a call for heat, the blower would ramp up to full speed after the burners were running for a short time. With the 58MTB in my new home, I have the fan running on a low speed (there are 3 or 4 speeds I believe) but when there is a call for heat, the fan shuts off while the burners heat up. Is this an issue? Am I better off turning the fan to auto?

3. If I understand correctly, you are saying to run the humidifier in "manual" mode. Meaning set a RH%, ignoring the automated outdoor temp stuff. The included jumper you mention would be used if the humidifier is attached to the supplied control, but if its controlled from the t-stat will that jumper still be necessary? I believe the t-stat has its own "automatic" or "manual" setting (similar to the aprilaire controller).
It all depends on which t-stat is used. Some will trigger the humidifier, others just the blower and will rely on the humidistat that comes with the humidifier to turn the humidifier on/off.

[skippedover]

Also, to add to the previous post:

4. The Carrier TP-PRH I mentioned is quite expensive and the only reason I lean towards it is because the furnace and a/c are the same brand. Should I consider other t-stats with humidity controls? If so, what is reccomended? The Pro1 IAQ seems to be highly regarded on this forum and significantly less expensive.

I believe you're actually referring to the T6-PRH thermostat. Yes, it's a little pricey but it has the ability to control the multi-stage furnace while using only 2-wires at the room thermostat. This is a distinct advantage if you would otherwise have to hire someone to run a new thermostat wire.

5. With a 2 stage t-stat, when does it utilize the second heat stage? Will I potentially see a decrease in energy cost vs a 1 stage t-stat (again I realize actual results may vary)?

Don't confuse efficiency with comfort. The longer run time on first stage will be marginally LESS efficient than when operating on 2nd stage. But the t-stat will should control staging. With your single stage t-stat it cannot and therefore the staging is control by the furnace using a time delay. Kind of silly to waste all that comfort when the cost for a truly 2-stage thermostat will bring significantly greater comfort. The efficiency loss is due to a slightly less efficient combustion process on 1st stage but it amounts only to about $5 per year. So you're only seeing about a .25% efficiency decrease and a 200% comfort increase. I just like everyone to know the real facts. The Honeywell IAQ and White Rodgers Big Blue along with the T6-PRH are all good and capable t-stats. However, the Carrier/Bryant T6 can be on-line registered (as should your other Carrier equipment) for a 10-year part warranty that IS transferrable to a new owner if you sell.

[letzleta]

Thanks again skippedover. This is exactly the kind of information I was looking for. I understand and concur with your comfort vs efficiency thoughts. Actually, the reason I have recently switched the fan to on instead of auto is because the heating was uneven from room to room and the longer run time makes a lot of sense in that regard. I have a 10 week old son and want to keep him comfortable. He is actually the main reason I want to get a humidifier installed asap. My wife and I have noticed that when we run a humidifier in his room overnight he sleeps better and doesn't get congested like he does without it.

Your help is greatly appreciated. Also, your comment about the transferrable warranty is appreciated. The system was installed in 2008 I believe, so that leaves me with 6 more years of warranty.

I wish you were in my area so I could hire you to do the work!

[skippedover]

Hmmmm. Deep roots here so it's better if you're in my area. Got some nice houses for sale in very beautiful areas. Come on down. And don't understimate the kid. Remember that warmer temps require more moisture be added so in fact, cooler temps will help with the stuffy nose issue. Point of fact; my wife was 5-years of age before her family had central heat in their home! And somehow she survived to this very day! Kids are very resilient and intelligent. We adults tend to think they're frail but in reality, they're more hardy than are we. Countless reports of families trapped in remote areas with all perished except the tot!

Good luck with your project and best wishes to all your family.

[letzleta]

Looks like the T6 models are Bryant and the TP models are Carrier. They appear to be identical other than the badging on them. The Bryant ones appear to be more readily available. I wonder if I could just swap the front cover from my old Carrier to a new Bryant unit? The manuals are identical, so would it be safe to assume either will work with the Carrier equipment?