I have a 4 Ton Trane Dual Fuel Unit that is 11 years old. The Evaporator coil went out last week and the compressor went out shortly thereafter. I'm considering either another Trane Unit; maybe a 15+ Seer Heat Pump w/Electric Back-up or a Goodman Unit. Any advice on the best mfg'ers to go with?

octopops

a couple of observations.

1.you need to re-check the price for natural gas and make certain that all charges/costs are included in the delivered price to your home. if correct, I would not even consider a HP unless paired with 80% eff VS furnace.

2.what size system both AC and furnace are you replacing?

3.your Bryant dealer should be questioned and chastised for quoting such large furnaces. for instance on option #1, an 80K 95% should be more than adequate for Atlanta area/climate and there are AHRI matched systems for that size paired with 4 ton Evolution AC condenser.

4.for future planning purposes, I would ask Bryant dealer about zoning controls for separating basement out from main floor. keep in mind, heating/cooling load for basements at or partially below grade are relatively small assuming even average insulation qualities.

5.any hot/cold spots for main floor and 550 sq ft room need to be addressed by dealer. Defintely, you should have an adjustable damper to control air going to this small room.

IMO

Tigerdunes (and others)...thanks very much for all the info/advice on my and the hundreds of other threads I have been reading.

Hope you have a few more minutes of final/add'l guidance.

1. 6200 Kwh at 12 cents, 1100 therms at 70 cents are my usage/costs for cooling/heating after all other usage/related costs are subtracted. A couple NATE certified HVAC guys have come up with $1.07 to $1.12 per therm with HP/Hybrid system...depending on size, HSPF, AFUE. So 'data' seem to indicate NO to HP/Dual with long term outlook of plentiful NG and rising Kwh...fossil fuel.
Perhaps Hybrid/80% in basement for next year!?

2. Old Not working: furnace: 100k trane ,whirlpool 3 1/2T
The Bryant guy is saying 5 ton coil is a must with 4 ton A/C, 100K CAV355 furnace!? Any thoughts.

3. Bryant guy says he has called AHRI and Bryant w/o success to find Evolution 80K btu CAV355 matched w/proper coil and 187BNA 4 ton A/C for fed tx credit. Can you provide some options/insight?

4. One big system for basement 1900sft, main 2180sft, 2ndflr 520sft w/zoning would entail new ductwork, zones at a cost that appears prohibitive vs cost of sep.sys for basement (50% below grade...concrete walls). i.e. quote of $1000 for zoning upstairs only from Bryant, $1900 from Trane). More zones, more controls...more things that can go wrong!?? And of course that can go right.

5. Upstairs...because of $1000 cost for modulating system dampers, I'm thinking MANUAL damper for the one supply run going to 2nd Flr...as only 'mom' is there in the winter...heat rises...can do later for $1300 if I need to. Your thoughts please.

Thanks again!

octopops

going down your list

1.you must include all related costs for delivery of nat gas to your home if you expect a true comparison on nat gas to a high eff heat pump and whether dual fuel is a reasonable option. it is difficult for me to believe that $.70/therm is an accurate cost.

2.I assume that existing 100K furnace is 80% efficient. Pls confirm.

3.here are two system configurations for option #1, an 80K 95% eff furnace, a 100K 95% furnace.

3747809 Active Systems EVOLUTION 17 PURON AC BRYANT HEATING AND COOLING SYSTEMS 187BNA048****A CNPV*6024A**+UI 355(A,C)AV060080 48000 12.60 16.00 1

3747756 Active Systems EVOLUTION 17 PURON AC BRYANT HEATING AND COOLING SYSTEMS 187BNA048****A CNPV*6124A**+UI 355(A,C)AV060100 50500 13.40 17.00 1

Both have the CNPVP coil-one is slightly larger explaining the performance/eff numbers difference. you do want the "ATA" tin plated coil finish.

4.you can not expect good control and comfort for basement area without zoning controls. I am not saying do this now. But if that's a possdibility down the road, then dealer should be aware of this and ask his opinion. I would prefer the zoning controls for the finished basement area over a separate system.

5.I see nothing wrong with a manual damper for the small room. does this room have its own return? it should.

Finally you should add at least a good 4-5" pleated filter media cabinet to the furnace for indoor air quality as well as protecting blower motor and evap coil.

IMO
Good Luck!

1. Just reviewed NG bills, current rate. After subtracting out my usual 18 therm, $45 hot water bill (ATL Gas + Scana auto $30 just for priviledge of receiving gas)...my 4 winter months use 206 therms avg at 59 cents per therm...including tax/ATL pass thru chg. The last four years rates $1, .93, .77, .63/therm.

2. Existing Furnace is 100K Trane 80 is on the front panel, and at least 12 years old. Certainly no more than 89% efficient.

3. thanks for the options...will discuss 80K option with my Bryant guy in AM...as it fits my Load...and when/if basement system is purchased...heat rises in this 11 ft high area...to my main floor...reducing therm need on main!? Not to mention, if windows go double pane, insulation added to attic, etc...Archie Bell and the Drells...from Houston TX...Tighten UP...

As an aside, my 'Bryant' guy says the drop in price from 100K to 80K Btu is at most a couple hundred...probably less.

4. Am confused on #4...Are you pointing towards one big system...with zoning/controls for basement and main?? This would mean all new duct work/$$$, expensive modulating zone controls, and larger system...??

Will do the manual damper for upstairs...and 4 to 5 inch 10 to 13 Merv air filter.

Thanks again, and I wish I could return the favor of your advice/comments...I'm pretty good at spreadsheets and analysis and anything postal.