Regular Guest
I saw an earlier thread from someone indicating with a two stage gas valve, you should get a two stage thermostat. This relates to the Trane XL 1400 model.
Is everyone fairly firm that the variable speed drive is worth the extra 1000 USD in Kentucky/Tennessee? I wonder how much the yearly savings are versus a fixed speed/single stage gas valve.
God Speed, Jim. We'll miss you - 2-26-23
A 2 stage thermostat will control weather the unit is in first stage, or second stage, not a timer.
The VS blower is more for comfort then savings.
But does save some money on electric to operate it, and some people can set their stat alittle higher because of the better humidity control.
Professional Member
Does a variable speed AH require a special thermostat? --Any fancier than the best Honeywell model you can pick up at Home Depot?
(Has switches for Fan on/off and Heat/Off/Cool on the other side?)
I have a new Honeywell model I just installed myself. Now I find my 19-year old Carrier has died. Can my new Honeywell unit be used with a new vari-speed AH?
God Speed, Jim. We'll miss you - 2-26-23
Yea, your stat will be ok for it.
But there are stats that can slow down a VS blower to aid in dehumifying, by slowing down the blower.
Professional Member
Ah! Are you saying that my AH's blower speed will not change, without a 'special' TStat? Is it the TStat that slows the blower, or circuitry inside the AH itself?
Professional Member*
Life Cycle Cost Evaluation needed
XL16i Heat Pump will be a much better, economical solution for yearly energy costs for KY.Originally posted by bebba1
This relates to the Trane XL 1400 model.
Is everyone fairly firm that the variable speed drive is worth the extra 1000 USD in Kentucky/Tennessee? I wonder how much the yearly savings are versus a fixed speed/single stage gas valve.
Designer Dan __ It's Not Rocket Science, But It is SCIENCE with Some Art. _ _ KEEP IT SIMPLE & SINCERE ___ __ www.mysimplifiedhvac.com ___ __ Define the Building Envelope & Perform a Detailed Load Calc: It's ALL About Windows & Make-up Air Requirements. Know Your Equipment Capabilities
God Speed, Jim. We'll miss you - 2-26-23
Yes, in order to slow the blower down, either a humidistat, or a thermostat designed to slow the blower down is required.Originally posted by alexb
Ah! Are you saying that my AH's blower speed will not change, without a 'special' TStat? Is it the TStat that slows the blower, or circuitry inside the AH itself?
Regular Guest
In the Honeywell Visionpro 8000 series, the 8110 is for "1 heat and 1 cool stage". The 8321 is for up to "3 heat and 2 cool stages". As I have a 2 stage system, I would assume I want the 8321 as the 8110 would not fully utilize the 2 stage system? Thank you very much
Professional Member*
The 8321 will control two stages. if you have a two stage heating and/or cooling.Originally posted by wiwbar
In the Honeywell Visionpro 8000 series, the 8110 is for "1 heat and 1 cool stage". The 8321 is for up to "3 heat and 2 cool stages". As I have a 2 stage system, I would assume I want the 8321 as the 8110 would not fully utilize the 2 stage system? Thank you very much
Some brand has a control of their own built in to help with better humidity removeal like Trane's "Comfort-R" control that the install set up on start up.
The 8110 will only do a single stage system.
Regular Guest
Thank you for the quick reply.
Professional Member
I checked with the company that I got a quote from, and they said circuitry internal to the AH controls the RPMs of the blower; not the TStat. (Thermistor)
However: If you have a 2-stage or 3-stage heat/cool system, then a special TStat is requird.
What I'd have, will be a single-stage A/C-only system, with a vari-speed AH. With this, I was told that the nice $50 Honeywell Tstat I installed will be just fine. (Digital, programmable)
Banned
Just make sure they do the wiring in the AH properly. I see it done incorrectly all the time.Originally posted by alexb
I checked with the company that I got a quote from, and they said circuitry internal to the AH controls the RPMs of the blower; not the TStat. (Thermistor)
However: If you have a 2-stage or 3-stage heat/cool system, then a special TStat is requird.
What I'd have, will be a single-stage A/C-only system, with a vari-speed AH. With this, I was told that the nice $50 Honeywell Tstat I installed will be just fine. (Digital, programmable)
God Speed, Jim. We'll miss you - 2-26-23
Then they forgot that some stats have the humidistat control built in to them that will slow the blower down.Originally posted by alexb
I checked with the company that I got a quote from, and they said circuitry internal to the AH controls the RPMs of the blower; not the TStat. (Thermistor)
However: If you have a 2-stage or 3-stage heat/cool system, then a special TStat is requird.
What I'd have, will be a single-stage A/C-only system, with a vari-speed AH. With this, I was told that the nice $50 Honeywell Tstat I installed will be just fine. (Digital, programmable)
But you can use the stat you have. It just won't slow the blower down.
Professional Member
Quote:
---->But you can use the stat you have. It just won't slow the blower down.
This still is in direct contradiction to what I was told this morning. The function that slows the AH speed CAN be in the Tstat, and it also CAN be in the AH. (True/False)?
I do understand the concept that the Humidistat function is built into some high-end Tstats, and that unit will control AH's RPM. I was told that a Thermistor in the AH can also control the RPM as well (in lieu of a Humidistat hanging on your wall)?
Maybe what I'm being told in the quote above, is that the Tstat I have, won't slow the blower RPM, but the Thermistor in the AH will(?)
Professional Member*
Alex, what is your brand/model of air hander do you have?
God Speed, Jim. We'll miss you - 2-26-23
Your stat won't control the blower speed.
There is atleast one brand that uses a dehumidistat, instead of a humidistat to slow the blower.
As asked by alexb, what brand are you looking at.
Professional Member
I'd been quoted the entry-level vari-speed from American Standard for the AH. I can appreciate that different brands are controled in different ways... The American Standard is the one where the contractor said that the Tstat didn't control the blower speed, but the internal circuitry of the AH did so.
Professional Member*
Ok, yeah a standard tstat will work with this just fine. As long the installer sets up the Comfort-R and other controls set up right, it will work great.Originally posted by alexb
I'd been quoted the entry-level vari-speed from American Standard for the AH. I can appreciate that different brands are controled in different ways... The American Standard is the one where the contractor said that the Tstat didn't control the blower speed, but the internal circuitry of the AH did so.
A person could add a dehumidstat to slow down the blower more. but it's not needed.
Regular Guest
Trane internal circuit board controls the motor, combined with the the motor module attached to the back of the motor. This is only applicable in True Variable Speed AHU's, Carrier and Lennox have them as well.
The TH8321 does not, I repeat DOES NOT control humidity. It will merely overshoot your temperature setpoint to close in on the humidity setting you have. With this setup, you are more than likely to have a home much cooler then your desired temperature.
Look for Honeywell to have additional models later this year, or early next with contacts to control and external humidifier or dehumifier.
Posting Permissions
Reply