How does this look? New Trane system

Ok, took the advice suggested here and replaced the 25 year Lennox pluse furnace and AC. System is as follows. It was installed yesterday.

Heat Pump - 4TWX5030BI000AA (XL15I)
Furnace - TUH2B060A9V3VAC (XV95) variable speed 2 stage
Coil - 4TXCB042BC3HCBA
Thermostat - TCON802AS32DA (outdoor temp sensor installed propane to come on at 35*)

HVAC contractor did load calculation on my 2,300 sq ft single level with full unfinished basement? Took his word that this is a good setup based on data. Location is triad of North Carolina.

I do have a question about the thermostat. I have 8 wire Tstat wiring. I thought I read that you needed 2 aditional wires to run seperately from the outdoor sensor to the tstat to operate correctly. I'm not sure they wired it that way. Any help or suggestions woul be appreciated.
Ken

Swicegk

I certainly question the size of a 2 1/2 ton HP condenser. I would want to see and review carefully your load calculation.

I also question the size of the furnace but not as much as the condenser.

I would want a new and correctly sized refrigerant lineset as well as a 4-5" media filter cabinet at the very minimum.

I want a true two stg thermostat that controls the staging of the furnace not from the furnace board.

IMO

Tigerdunes,
Can you expand on your post? 2-1/2 ton to much or too little? New proper sized lineset was installed with the system. Can you explain the wiring set up of tstat that you describe? Sorry for the questions, just trying to learn.

Vision Pro or Prestige IAQ or the competition. The 802 won't properly stage the gas backup, you have to use the timer which times to high just as you need LESS heat. Sad to get such a nice system and not get the control that will give you so much more comfort. Dehumidify on demand too.

Never had a problem with a 8320/802 not having separate 2 wire for the outdoor sensor.

Baldloonie,
What purpose is the outdoor sensor they installed. Are you saying it is of no use with the TCON802 tstat? When you say stage the gas back up are you refering to gas taking over at a set outdoor temp? Will the Vision Pro 8000 do this, defrost on demand and humidity control with my current system minus my current tstat. Any special wiring requirements?
Thanks,Ken

The outdoor sensor tells the system when to change to gas, need to have that. You have a 2 stage gas furnace. It runs at 60% on low then times up to 100% after say 10 minutes. The most comfortable way to decide whether to be on low or high gas fire is having a thermostat measuring the house temp and knowing whether the house is getting close to setpoint. The 8000/802 can't do that. The VP or Prestige IAQ can as does the competition.

Demand defrost is there regardless.

Dehumidify on demand can be done with the IAQ models and the competition. That's where the furnace blower slows down 20% for extra moisture sucking when the humidity inside rises above the setpoint.

Swicegk

Baldloonie nailed it on the thermostat.

However, I would want to see the load calc on cooling and heating. In writing on the software letterhead with design temps clearly spelled out. What size condenser are you replacing? It would seem that staying off propane heat would be a high priority. I would definitely consider moving up to a 3 ton condenser whether XR15 or XL15i. I would want the evap coil choice to be the best matching mdl in performance/efficiency numbers paying close attention to HSPF. I would want a new and correctly sized refrigerant lineset. And finally a pleated filter media cabinet.

IMO

OK, let's make sure I understand this correctly.

The outdoor temp sensor I have, set at 35* to switch from HP to Propane is good to go?

Need upgraged tstat to more efficiently control 2 stage furnace? (inside temp vs timer)

Defrost on Demand is built into the XL15i HP and not dependent on the tstat?

What exact model # of the Vision Pro should I ask for to accomplish this? Will it utilize the 8wire I currently have?

I don't generally have an issue with humidity as I run a dehumidifier in my basement that seems to help with the upsatirs humidity levels. I think I'd prefer not to step up to IQA tstat. Sorry for all the questions but I want to better understand the system and take advantage of features I spent good money for.
Thanks, Ken

Ken

I can not emphasize this enough.

Load calc, load calc, load calc...

Pay attention to Baldie's advice on the thermostat.

I would want the IAQ for controlling stages of furnace VS timer plus dehumidify on demand feature. If you don't get a thermostat with true staging, then you will be on high stage practically all the time. That will ake you feel good with propane prices where they are.

IMO

Quote:

---

Originally Posted by BaldLoonie

Vision Pro or Prestige IAQ or the competition. The 802 won't properly stage the gas backup, you have to use the timer which times to high just as you need LESS heat. Sad to get such a nice system and not get the control that will give you so much more comfort. Dehumidify on demand too.

Never had a problem with a 8320/802 not having separate 2 wire for the outdoor sensor.

---

+1. For a very small additonal amount, this is the best non communicating thermostat for dual fuel set-ups. Dehumidify on damadn will make a big differene in comft, since you'll be controlling to a humidity level as much as temeprature. Humidty affects human comfort as much or more than temperature.

IF thye are pulling a new lineset, running new thermostat wire and a seperate shielded cable for hte tmepratuer sensor should be a big deal.

They need to pay attention ot thermostat location and make sure the condenser isnt; too close to the house. THe discharge of the Trane XLi series tend ot cause recirculation and blows air against the house. IF you mount hte senser too close to the unit on the wall, it can be influenced by air off hte condenser. I've seen temperature be off by 5-7F.

The sensor also needs to be in a shaded location so the sun doesn't heat it up.

For a Honeywell, the YTH9421 or YTHX9421 Prestige IAQ. Use 2 or 3 wires. The Prestige can be internet controlled with the Redlink gateway if you like that idea.

Also, the Aprilaire 8910 is similar in features & price to the Vision Pro IAQ.

The way it works now, when the stat calls for gas heat, it comes on low. After 10 minutes it times to high and runs on high til the stat says no more. When it gets really cold, you'll be constantly switching between low, high & off. Not comfy. With the other controls, the stat decides if you need low or high. It can run all day on gentle, quiet low. In your car on a cold morning, do you turn your heat off? No, leave it on low and you are comfy. Why not have that much comfort at home?