The obvious question...what model furnaces, evap coils, filter cabinet, thermostats?...makes a difference...

IMO

Read my posts. I was bid the 2-stage XR17 (same as your American Gold Standard) for $14,800. That is for TWO 3-ton systems as they don't make a 2.5 ton model so my price installed with the correct AHRI parts was $7,400 each system or basically a grand less per system (upstair is an 80% furnance, downstairs is a 95%).

Now in the beginning bidding stages the Trane folks DID have their prices WAY high so you have to let them know that they are "out of line" vs. the market. Houston and Charlotte are virtually IDENTICAL markets so don't let anyone on here or the internet try to play the "It's more $$$'s in Houston due to blah, blah blah..."

I actually did NOT buy the Trane but rather selected a 1-stage outdoor AC system with variable speed natural gas furnance for a number of reasons. No need to re-hash everythign here. Just search on my moniker

My apologies for not providing details in the original post. Here are the details for each options, with the quotes (with all the rebates, except the tax credits).

1. Trane XR16 system,
16 SEER ($7,999)

Cond: 4TTR6036B13 , Coil: 4FXH036AC3, Furnace: TUD1B080A9H3,
Thermostat: Honeywell Pro 6000 Programmable

2. Trane XV18/XC80 system, 18 SEER ($9,990)

Cond: 4TTV8036A1 (XV18), Coil 4TXFH036CZ3, Furnace: TUD2B60ACV3
Thermostat: ComfortLink Communicating Connected Control w/ Media Bridge,
(TECONT 850)

3. AS Silver
16 system, 16 SEER ($8,020)

Cond: 4A7A6036J1000A, Coil: 4TXFH036CZHHB, Furnace: AUE1B0809361A
Thermostat: ACONT 824

4. AS Gold
17 system, 17 SEER ($8,376)

Cond: 4A7A7036A1000B, Coil: 4TXCB006DS3H, Furnace: AUD2B080ACV32A
Thermostat: ACONT 624

5. AS Platinum 18i Variable Speed system, 18 SEER ($10,354)

Cond: 4A7V8036A1000B, Coil: 4TXCB006DS3H, Furnace: AUD2B080ACV32A
Thermostat: AZONE 950A

An additional option is to add PerfectFit Filtration System with Honeywell 5" filters for $325. Is this a better option then the current 1" return filter that we have? We do have excess dust and some allergy issues in the house that impacts my wife and daughter and would like a cleaner air option as long as it is low-maintenance.

Once again, I would appreciate any and all suggestions / recommendations that the experts can provide, as this is my first ever HVAC project! And I need help to navigate this complex maze of options.

First I would want to see a load calculation especially for heating. You might could get away with the 60 K model furnace since your home has 2 systems. But the nicest and best value system quoted is #4. I would want the 824 thermostat over the 624 on dealer's dime, not yours. And if you don't already have a filter media cabinet, I recommend one. I assume dealer plans to reuse your lineset and have it flushed. Yes or no? It must be in good condition and correct size. I need to check AHRI directory later, don't have time now.

IMO

Thanks, Jay & TigerDunes for your valuable feedback.

Jay, I felt the the numbers were on a high side, based on some of the numbers I have read on this forum. Will check out your thread.

IMO, thanks for the suggestions on 60K furnace and 824 thermostat. I will check with the dealer on both. I will go with the filter media cabinet ( I assume that is the 5" whole system filter option). Should I go with AS filter or Honeywell? And what about AccuClean or CleanEffects add-on option?

About the load calculation, I have talked to eight different Trane and AS dealers/installers. None of them offered to do it. When I asked for it, every one of them said it was not necessary, since you are replacing a 3T system. Any change wouldn't be significant enough to change the size to 2T or 4T (since no half ton systems are available for the higher efficiency models). Few of them said that any change is the size will require redoing your duct work (about $2,500 for each of the two units).

Since my downstairs unit is 2.5T (working fine for now), when time comes to replace it, I will need to change it to 2T or 4T, so I better get the proper sizing of both units done. I will follow up with the dealer I decide to do with. They may charge me to do that. We shall see!!

Once again, thanks a bunch!!

My downstairs COIL is a 3-ton system whereas the outside unit is a 2.5-ton system (AHRI #8112091). According to this HVAC company this is more efficient than what they would have had to of done with a Trane system that did not have a 2.5-ton outside option. They said that on the Trane they would have had to of programmed the system to run at a partial operating capacity.
On a side note, these guys have been here all day and it looks like they are getting close to finishing. I can already tell a HUGE difference in the loudness of the outdoor units. We couldn't even tell that one was running until we walked over closer to it. Once we got there you could hear it but it was a good bit quieter than a normal conversation. As we stood there one of my neighbors Rheem AC units kicked on and it was a HUGE difference.

One note - My Trane & Lennox quotes INCLUDED the 5" MERV media cabinets for the prices listed in my posts.

The rule of thumb for SEER that I use is 4% per point. This would be 8% going from 16 to 18. Depending on your electrical rates and the amount the unit is used, I would feel that it will take quite a while to make up the nearly $2000 price difference.

AC/HPs are sized in tonnage, furnaces sized in BTUs and efficiency. How large is your living space for this system? I recommend AmStd Perfect Fit Media cabinet. Simple, filters last up to one year, no maintenance/cleaning, and less expensive than AccuClean Electronic Cleaner. Link below.

IMO

Perfect Fit Filter

@TigerDunes, each of my floor is 1320 Sq. Ft., including the 2-story entry way.

On your earlier post, you recommended that I explore the 60K furnace option for AS Gold 17 system (option #4). I am in the process of doing that. What would be the cost difference between the two furnaces? And would the change in furnace capacity require any change to the coil that should be selected? What coil model would you recommend? I looked up AS web site, where the models are listed by categories, and I am not sure which category would apply to me. I have been quoted two coils by two vendors: 4TXCB006DS3H (option 4) and 4TXFH036CZ3HHB (option 3) - the former (with different last 4 characters - DS3H) is listed on AS web site as 24,000 BTU capacity and the later is listed at 36,000 BTU (see list below). Which one makes more sense?

HIGH EFFICIENCY STAGED SYSTEM CASED COIL CONVERTIBLE
UPFLOW/DOWNFLOW/HORIZONTAL LEFT/HORIZONTAL RIGHT
Model Capacity H W D Weight (lbs)
4TXCB003CC3HCA 24000 22.6 17.5 21.5 45
4TXCB004CC3HCA 36000 26.9 21 21.5 49
4TXCB005CC3HCA 36000 26.9 21 21.5 51
4TXCB006CC3HCA 24000 22.6 21 21.5 48
4TXCB007CC3HCA 36000 26.9 21 21.5 51

CASED COIL HORIZONTAL FLAT
Model Capacity H W D Weight (lbs)
4TXFH024CZ3HHA 24000 22 10 37 56
4TXFH033CC3HHA 34000 22 10 38 46
4TXFH036CZ3HHA 36000 22 10 37 64

The above lists are for the AS Platinum Indoor Coils from their web site.

Again, thanks a bunch for your help in figuring this out so I can get the right HVAC system.

@JaySeifert, I looked at your quote. Mine is similar to yours with
80% efficiency furnace (same size as yours, 80K). That system of yours
was quoted less than $7400 (since the 95% eff furnace should be more
expensive). BTW, what coil models did they quote you?

Thanks for the
info and the details.

@weedmeister, thanks for the trade-off information for SEER rating vs. cost savings. Will take your recommendation and not go for variable speed 18 SEER system. As of now, I am likely to go with Trane or AS 17 SEER system with 2-stage compressor/condenser and 2-stage furnace with multi-speed blower and 824 programmable t-stat (option 4 or its Trane counterpart). Your argument combined with @TigerDune's feedback made it a no-brainer choice!! Thanks again! :-))

I tried to look up AHRI directory to find out the exact SEER/EER rating and Tax Credit qualification, and stumbled upon another minefield!

I searched for the Outdoor Unit Model number and found the above certificate (Ref # 6452298) for 80K furnace and Ref # 6452303 for 60 K furnace, both with same SEER/EER rating (16/12.2), and none of them qualify for the tax credit!!

Can someone help me understand this? What is the Indoor Unit Model number? Is is the coil model number? None of the combinations listed on AHRI web site has this number that matches with any quotes I have received so far.

I would appreciate some help!! Thanks!!!

The indoor unit is the coil model number. Sometimes you will see an asterisk for a character meaning that models apply for the same AHRI certificate. So you want have to enter a shortened version of the model number and search for the one you are looking for. It would be easier to ask the contractor for the AHRI directory number and then look it up.

The federal tax credit for an AC condenser is $300. You need a minimum of an EER 13 in order to qualify. You may spend more than $300 trying to get this credit.

8995446 ActiveSystems AMERICAN STANDARD GOLD17 AMERICAN STANDARD 4A7C7036A3 4TXCB006DS3 1070 860 *UD2B060ACV3 36800 12.50 17.00 3RCU-A-CB 262

this would be the system you want. And I can't see you needing more than a 60 K size furnace even at 80% efficiency. Since you have a lower floor system, you will get some residual heat off that system for the second floor. I know it can get cold in Houston but the average winter temp is around 50 degrees. I would want the Perfect Fit Media cabinet and 824 thermostat. Dealer plans to reuse refrigerant lineset? If so, it must be sized correctly. You should verify this.

IMO

According to my research using the AHRI Directory, there are no matches for the GOLD17 (XR17) that meet the qualifying standard for the $300 tax credit using the 60 K furnace (XV80) that I recommend. To get the credit you would need to drop back to a single stage 16 SEER model or upgrade to the more expensive var speed condensers. I would not pursue either.

IMO

Thanks, TigerDunes for your feedback.

I noticed that your configuration says GOLD17 series outside unit, whereas the ones I looked up (based on model 4A7A7036A1 were all PLATINUM XM Series. Furthermore, the AS web site lists Gold 17 models as 4A7A70XX and it does not mention Platinum XM series. Any thoughts on why this anomaly? Are there any functionality differences in these two? Any cost difference?

I did notice that your system was 3-Phase system where as mine were listed a 1-Phase.

8736645 Active AMERICAN STANDARD PLATINUM XM
4A7A7036A1 4TXCB006DS3 1010 810 *UD2B060A9V3 36000 12.50 17.00 1 RCUACB All 267

8736646 Active Systems AMERICAN STANDARD PLATINUM XM
4A7A7036A1 4TXCB006DS3 1020 835 *UD2B080A9V3 36000 12.50 17.00 1 RCUACB All 267

8736647 Active Systems AMERICAN STANDARD PLATINUM XM
4A7A7036A1 4TXCB006DS3 1075 855 *UD2B080ACV3 36000 13.00 16.75 1 RCUACB All 271 Yes

8749834 Active Systems AMERICAN PLATINUM XM
4A7A7036A1 4TXCB006DS3 1070 860 *UD2B060ACV3 35800 13.00 16.00 1 RCUACB 282 Yes

By the way, my AS dealer quoted me system with AHRI # 8736647 (#3 above).

The last one uses 60K furnace (Platinum SV80), but sacrifices 0.75 SEER. Which of these is a better option?
I also noticed that the furnaces ending in ACV3 tend to qualify for Tax Credit, where as the ones ending in A9V3 do not, regardless of size (60K or 80K)! I think the difference between the two types is the communication feature that the former two have (as far as I can tell, but I could be off-target here!). How much would be the cost difference b/w these two types of furnaces? Any comments or feedback?

Once again, thanks everyone for their valuable input. I am ever so close to finding the "Goldi Lock" system for my home!! :-))

First off, I have never liked the method AmStd uses to identify their condenser models, ie Platinum, Gold, Silver. According to my research, the 2 stage Platinum XM is now identified as Gold 17. You will note the different Mdl numbers 4A7A for XM and 4A7C for Gold 17. I have no idea what if any differences there are between the models. I would suspect very minor other than badging. Both Mdl condensers are showing as active in the AHRI AC directory. That may be an error. I see nothing wrong with your 4th system, AHRI #8749834. It would qualify for the tax credit. You would lose a little SEER efficiency which would affect your operational costs, albeit inconsequentially. I suggest you confirm all of this with your dealer. The Platinum XM might not even be available any longer.

IMO

@TigerDunes, thanks for that insightful analysis and explanation. Things are finally becoming leads foggy! :-))

separately, I God one more quote from another Trane dealer (I had to wait two weeks for him to come out, inspect my system and give me a quote), without any model details. when I asked if he would share his sizing calculations and model numbers of the components (incl the thermostat), he called me to inform me that he is not interested in doing my job, because I am asking too many questions and don't trust him. He does not do heat load calculations and is not able to address the issues like hot spots in some areas of my home!! I was flabbergasted. I guess he has too much business to care for a new customer.

He thinks asking him for the description of what you are buying is too many questions?

He has done you a favor of being up front on how he does business and saved you a lot a grief.

@TigerDunes & Everyone else, been away for the week-end, dealing with another home remodeling project, while awaiting answers and references from the AS dealer.

Since no one is willing to do the heat load calculations, I took it upon myself to explore that. Found an online Manual J & S calculator. Measured everything about home and entered. Took me an afternoon, but I did get the following results:

To repeat the last line,

Total BTUs Cooling: 36,577 Total BTUs Heating: 42,432

This is for a 2-story house with 2 HVAC units.

Since I am by no means familiar with this subject, it is quite likely that I may have made some incorrect data entry. But, to the best of my abilities, the information entered is pretty close to accurate.

The question I have is how should I interpret the results? The BTUs are for each unit/floor of the house or the total house? In that case, how can an 80K furnace be justified for upstairs (and similar one downstairs)?

I followed this up with the sizing calculation (Manual S) which is just a click of button from the heat load calculations. Here are the results:

Cooling (Min/Max): 36,577 / 43,892 BTUs Heating (Min/Max): 42,432 / 59,405 BTUs

I have made some very conservative calculations - e.g., 2 degrees extra cooling and heating then what we normally use. So, the question I have is what sizes of compressors and furnaces do I need according to these calculations? This is where my novice attempts run aground! :-(

I would appreciate any comments, suggestions, feedback or advise from experts. Perhaps, I am going into unnecessary details, but I am not comfortable spending $15K on two new systems without understanding what my actual requirements are. I certainly do not wish to pay for "extra" capacity if I do not need.

Thanks in advance to all those who have contributed and helped me through this ordeal!

Follow-up to my earlier post about the heat load calculations:

Looks like I may need to do separate heat load calculations for upstairs and downstairs. Is that correct?

The above numbers are too low - compared to my current systems (3T + 2.5T).

I would appreciate if any of the experts here can give me their feedback or comments.

Thanks in advance.

What specifically is your quandary on the load calculation-I assume cooling only?...how did your existing 3 ton perform as far as providing upstairs necessary comfort?...did upstairs system ever run continuously?...did upstairs temperature ever climb and fail to hold your thermostat setting in cooling mode?...post back...

IMO

My upstairs system has not been cooling at all, even after running for quite a while. couple of techs checked it out and said that the compressor is broken/dead and there is a leak somewhere in the system whereby there is significant loss of freon. So, either I replace the compressor and find and locate the leak, or replace the whole system. Given the age of the system (28 years), it would be best to replace it (consensus among multiple techs that came out and checked the system).

the downstairs, while cooling to the set temperature, seems to run for a longer time to get to that temperature. Both the system were topped off last spring with freon. So there could a leak or the system is very inefficient.

My quandary is on the heating side. some dealers are quoting 80K furnace while others are quoting 60K ones - 2 stage models (XV80 or XC80 for Trane and Platinum SV80). Not sure which one would be the better option.

None of the dealer's are doing load calculations, saying that it is not necessary. I need to decide which way to go. Hence request for advice.

can anyone give me an idea of cost difference between the 80K and 60K furnaces? one of the dealer told me it would about $75, not worth changing the optimal SEER combination.

Any comment, advice, recommendation would be greatly appreciated.

Sounds like the Trane dealers in your neck of the woods are schmucks. Tell them you'll only give them the job with a proper load calc and sizing to match.

@sktn77a, I am tempted to do that, but I am concerned that I will be without AC for a long time. the high temps are touching 90 deg most afternoons now a days!!

I really can't afford to wait. I have been at this for the past two months. out of 10 - 12 dealers, no one is prepared to do load calcs! Thus in spite of the fact that according to Trane / AS web site, the dealer's are supposed to do it as part of any quote.

If you want something done right, do it yourself :P

http://www.loadcalc.net/

Then you will know what you need.

The price difference between a 60K and 80K BTU furnace is small. But you are not buying the smaller furnace to save money, or getting the bigger furnace because it is a bargain. You want the correct size furnace.

If you can invest $49 and want something that is more accurate than the free on line calculators, then get a copy of HVAC calc.

@mike_home, I agree with you. My purpose is to get the right size of the furnace. Saving money us a byproduct.

As I understand it, incorrect size of equipment can be less efficient and less "comfortable" - based on some expert advice on this forum.

I can buy the software, but I would not know how to use it correctly. So I am stuck between proverbial rock and the hard place!!

@Vith, Thanks for the suggestion. Does the software come with the instructions manual? As I mentioned above, I will need to learn it.

@Vith, I tried to do it with loadcalc, the online tool, but came up with some ridiculous results (see my post above with the results). Not sure what I did wrong.

"After the location is chosen enter in the the structure values, insulation etc.. On the bottom left of the screen there will be an instruction button to click that will explain more details."

From the home page

for the OP...you will never get me to believe you need an 80 K 2 stage furnace for 1320 sq ft living area in Houston, Tx...stay with my original recommendation below either the 3 ton Platinum XM or Gold17. Thermostat 824 and Perfect Fit Media cabinet.

8749834 Active Systems AMERICAN Standard PLATINUM XM 4A7A7036A1 4TXCB006DS3 1070 860 *UD2B060ACV3 35800 13.00 16.00 1 RCUACB 282 Yes

IMO

Thanks @tigerdunes. I will go with that. During my last meeting with the dealer, I tried to ask him why is he suggesting bigger furnace, he said it was to get 16.75 SEER system, which would be more efficient than the 60K furnace (16 SEER). That does not make sense to me. Why would the furnace size impact cooling efficiency? Besides, we don't use furnace more than 3 months - that too sparingly, given out temperatures here in Houston.

In your recommended configuration the furnace ending numbers are ACV3. One of the Trane quote I have received has the furnace with A9V3. Is there any significant difference between the two - cost wise or functionality wise?

Thanks @Vith for your suggestion.

I tried the calculations myself using loadcalc, but I botched it up rather spectacularly! (see my posting above dated May 9th) :-(

Mike is correct. However, I have made a mistake identifying the correct model number of Trane's XV80 furnace and AmStd equivalent. There is no qualifying tax credit using the 60 K size furnace paired with either the XR17, Gold17, or Platinum XM 2 stage AC condenser. Still I would recommend either of systems below paired with Perfect Fit Media Cabinet and 824 Thermostat.

8736645 Active Systems AMERICAN STANDARD PLATINUM XM AMERICAN STANDARD 4A7A7036A1 4TXCB006DS3 1010 810 *UD2B060A9V3 36000 12.50 17.00 1 RCU-A-CB All 267

8995457 Active Systems AMERICAN STANDARD GOLD17 AMERICAN STANDARD 4A7C7036A3 4TXCB006DS3 1010 810 *UD2B060A9V3 36400 12.50 17.00 3 RCU-A-CB 259

my mistake, my bad.

IMO

Thanks, @mike_home and @tigerdunes.

I followed up on your advise and asked AS dealer to quote me the 60K platinum furnace (originally, he had quoted an 80K platinum one). No change in price! So I can get either one, but they will charge me the same $$!

The other Trane dealer that I have short listed is quoting me 60K XV80 furnace, with the configuration @tigerdunes suggested in the previous post.

However, I did notice that the Evap Coils they have quoted are different ones:

4TXCB006DS3 vs. 4TXFH036CZ3.

The Trane dealer told me that these are two different types of coils (Box Coil vs. Slab Coil, respectively). With the second one, the 60K XC80 furnace (*UD2C060ACV3) will give 13.00 / 16.00 rating, qualifying for tax credit.

So my final (hopefully!) questions are:

If there is no cost difference b/w 60K and 80K furnace, what are the negatives for opting to go for a bigger furnace (to get the tax credit)?

Is it worth going to XC80 furnace (60K or 80K) to get the tax credit as long as the cost difference is less than $300)? Would I get any benefit of the "communication capability" of the furnace or to get any benefit, I also need to upgrade my outside unit)?

Which of the above two coils (DS3 vs CZ3) is better - design / functionally / performance wise?

May be I am nit-picking here, but lack of knowledge/expertise is making it difficult to figure out a "right" combination. The dealers here are not very helpful. They just want to use the same components that they have used in the past.

I sincerely appreciate everyone's help here. You guys have been God-send to help me navigate through this minefield of HVAC land!! Somehow, a simple Thank You does not seem adequate. But unless I can think of a better way to express myself, that's all I have. So, Thank you all, esp. @mike_home and @tigerdunes.