The VisionPRO IAQ is what you want, which is essentially the TCONT900. I believe the contractor is right... or at least it can only be used with communicating air handlers.

ryanhughes...
Ok. So are you saying that even though the 'VisionPRO IAQ ...is essentially the TCONT900', the IAQ will work with the 15i, and slow down the fan?

What would the Trane 803 do that the 802 does not do (based on the contractor's recommendation)?
Thanks, Gary

goddi

Trane's TCON900 stat is not compatible with the XL15i.

Trane's 803 stat has "overcooling to dehumidify" feature. The 802 does not. The HW VisionPro IAQ stat has a separate "dehumidify on demand" feature by controlling blower speed. If you live in an area like DC, then this is the preferred stat. Trane branded stats are still way behind the curve to the Infinity controller.

and not meaning to beat a dead horse, I stand by previous advice from last Sunday.

Posted by tigerdunes (My Page) on Sun, Aug 24, 08 at 14:57

goddi
several final thoughts and I will leave it with you.

1.it is just as bad to be oversized as undersized for AC cooling whether from a straight AC or HP

2.I would not size HVAC for an unfinished basement that may or may not ever be finished. especially for a future owner of the home. let them put in a small separate system. You should think about this strategy long and hard because oversized HVAC is more costly to operate, can affect equipment life, and yield poor inside comfort.

3.a properly sized HP will pay for itself considering your inexpensive electric rate.

4.if not a HP, ask dealer about placement of venting for the high eff gas furnace. I have to say it one more time-an 80% without a HP is a dinosaur.

that's all.

Good Luck!

IMO

Gary,

Were missing what air handler is being matched with the 15 SEER unit. That will make the difference on T-stat choices and benefits available.

Will it be Variable Speed?

OP was looking at two stg VS 80% eff furnace, lives in Northern Va area.

TD

Ok...I am getting really confused about this t-stat. I thought I had it all ironed out. With all the posts suggesting that the Trane 900 (same as IAQ, I understand) is the way to go to address the humidity problem.

Then I hear that it is not compatible with the XL15i, only the XL19i. But then it may depend on the air handler.

Here's the list of components for the XL15i A/C, XV80 VS 2-stage gas furnace I am planning on getting:
Condenser-4TTX5060A1000A
XV80-TUD120R9V5K
Coil-4TXCD064BC3

Can the 900 be used with the above items?
If the Trane 900 is only compatible with the 19i, is there any reason not to upgrade to that model? I don't know yet the price increase. Please clarify this for me.
Thanks much for all your input...
Gary

Ok, in this post I see no mention of indoor unit anywhere until last post. (perhaps previous discussion)

VisionPRO IAQ or 900 is definately compatable. The outdoor unit is only 1 stage which is set on the stat, ending up with 2stg ht/1stg cool, with enhanced dehumidify and humidify (if added/used) and enhanced blower, among others.

Ah... Ok. So if I understand this right, it does not matter what the outdoor unit is (whether it is a 15i or a 19i). The t-stat controls the indoor unit...the fan (blower) or the VS XV80-TUD120R9V5K?
So I don't see why the contractor would say the t-stat is not compatible with an 'outdoor unit'...
I hope I understand this better. I'll have to have more discussions with the contractors.
Thanks... Gary

Well, I just talked to the Trane distributor tech guy in my area and he said the Trane 900 is a communicating t-stat that will NOT work with my set up. It is for the XL19i, not the XL15i. He said only the Trane 803 will do the additional dehumidification by overcooling. He did mention a 16i in coming out soon that may be a 'communicating' system that will work with the 900.
So it looks like the best I can do is the Trane 803. Probably good enough. No other choice that I can see.
Thanks... Gary

You want the VisionPRO IAQ. It is a better thermostat than the TCONT803 for humidity control. You need a communicating indoor unit to use the TCONT900, which would be the XC95. I think that's just the way the ComfortLink II system works--communicating components. Will the TCONT803 work? Sure. Can it take advantage of your variable-speed blower? No.

ryanhughes...
I agree I want the VisionPRO IAQ. But I can not physically have the XC95 or any of the superefficient furnaces installed. The vent pipes would have to be installed under the front porch or rear deck but there is not enough clearance. So the XC95 is out; and the Trane 900 is out. So I am left with the 15i, 803 and the XV80. I feel like I've been going around in circles but now I think, now, I have at least tried to understand and figure out what is best for my situation and I have learned alot.
Thanks for all the help. Gary

Ah... I thought I had run out of questions but...
What is the difference between the Honeywell VisionPro 8000 and the Trane 803?
Thanks... Gary

Goddi,

You CAN use the Honeywell VisionPRO IAQ with your setup. You cannot use the Trane TCONT900. Just to clarify. The Trane TCONT803 is very similar to the Honeywell VisionPRO TH8321, with a Trane logo.

ryanhughes...
Now you have me really confused. If the Trane tech guy says that my setup doesn't allow for the 'communications' that the HW VP IAQ 900 uses, how can it be used???

The tech guy said the dip switches on the blower would be set to 350 instead of the regular 400 cfm to get better dehumidification with the Trane 803. But it would not be controlled or 'communicated' via the t-stat.

Please help me understand this. Maybe it is not conflicting information but I just don't get it. One contractor says he will put in the Trane 803; the other, an HW VP 8000; and you say the HW 900 IAQ will work. They say it won't. Please give the explanation for Dummies. I don't understand which t-stat should be used and why it should be used.
Thanks... Gary

The Trane is a communicating thermostat with the components. The VisionPRO IAQ doesn't communicate with the equipment itself; it has an EQUIPMENT INTERFACE MODULE that the thermostat communicates with. Thus, the VisionPRO IAQ can be used definitely. If they are telling you otherwise, they need to get their act together. Explain to them that the TCONT900 and the VisionPRO IAQ are different in that the IAQ uses an EIM. The TCONT900 communicates with the equipment itself.

Ah...Ok, bear with me. When they install the HW VP IAQ 900 t-stat with my system, they also install the EIM, and that will communicate with and control the blower. Is the EIM normally part of the HW VP IAQ 900 package?
I had never heard of the EIM. Thanks... Gary

Yes, the IAQ package from Honeywell comes with the EIM. Model number for the package is YTH9421C1002. The TCONT900, as far as I know, doesn't have the EIM as it's built in, thus requiring the communicating components.

ryanhuges...
Thanks for clarifying this for me. I will check further with the contractors to see if they will do it.
Gary

Right now there is only 1 furnace model that's compatible with the TCONT900. It's a 3 stage 95% efficient Communicating furnace. Use the IAQ.

I also have a XL15i. I also would like to have a
humidy control.
After looking at all the text, I beleive I should swap the T800 for a T803.
I do not think the people would swap the unit with no cost.
What do you think a fair price would be?
I live in Rancho Palos Verdes, Ca 90275
Thanks, B.