VisionPro TStat

[gofly]

I have a Trane 2 stage gas furnace and a Trane single stage A/C unit. The contractor installed a single stage Honeywell thermostat. He set the furnace to run at low stage for 10 minutes and then high stage if more heat is needed.
The A/c seems to short cycle. Maybe 5-6 time an hour. Runs for 5-7 minutes and shuts off. Is this type of cycling hard on the a/c unit?
If I were to installed a VisionPro programable t-stat , which model should I install?
The TH8110, 1 heat, 1 cool, and let the furnace run on a time basis , rather than demand.

Or the TH8320 or what every model cover the two stage heat?
Does it matter on the multistage t-stats, if the a/c is only single stage and the heat is multi stage?

[mayguy]

Get the 8320, and make sure the dealer sets it up right..

2-stage heat (don't use timer, you'll need another wire.

1-stage cooling..

On this pro, they can set the A/C cycle per hour..

If you have an extra wire, run the common wire and you can have a lit up back light all times.. that needs to be set also..

[travisfl]

Originally posted by gofly
The A/c seems to short cycle. Maybe 5-6 time an hour. Runs for 5-7 minutes and shuts off. Is this type of cycling hard on the a/c unit?

Yes, and it means you are getting poor humidity removal.

How was your A/C sized?

[tpa-fl]

The TH8320/TH8321 stats are "universal" and can easily handle multistage and/or single-stage equipment, including multi heat & just a single stage for cooling if need be. Cycle times can be set in the stat, 'though 5-7 mins per run is terribly inefficient for cooling... sounds like your unit is either oversized or the installer configured the stat wrong. Either way, get the installer back out there & have them correct it.

I don't see any reason to have a multi-stage furnace (or AC) and no practical way to control it.

[gofly]

Thanks guys for the comments.
House is aprox 1200 sq ft,+ full basement. SW OHIO
Basically I had a 2 ton 18 year old a/c unit. I have a black roof , and absolutely no shade on the south side of the house.
In the summer the a/c would run almost non-stop when temp was above 82 deg. , and with the stat set to , say 74 degrees. It would eventually satify the t-stat after 2-3 hours after the sun went down. I added 12 inches of attic insulation in the fall, so the attic has about 25 inched fiberglass blanket.
So when discussing with contractor it was decide to go with a 2.5 ton a/c cndenser & coil.( I run a dehumdifier in the basement as well) I must admit I really don't notice any discomfort as far as the humdity is concerned.
And just looking at mny electric meter , I have only consumed about 60% of electric from last year, under comparable conditions, so I am pleased with the results from the replacement.
I just thought , that long term , this short cycling would take a toll , on the longevity of the a/c unit.

[dash]

With the additional insulation,you may only need a 2 ton,but only a Manual J Load calulation will tell.



Click on the bullseye above to do your own.

[travisfl]

Originally posted by gofly
So when discussing with contractor it was decide to go with a 2.5 ton a/c cndenser & coil.

How did you decide this?

http://www.proctoreng.com/articles/bigger.html

Do yourself a favor and ask the contractor if he did a load calculation before installing the 2.5 T system. If not, you need to do one now, and then if necessary, replace the system with the correct size.