Need advice on VS furnace opportunity

[rmrc]

I recently had a Trane HVAC system installed in my home. The incorrect furnace was installed (supplier and dealer share blame) and since the dealer has to remove and replace the single stage/speed 95% furnace they have offered to upgrade me to a 3-stage 100k max BTU XV95 (I only see 2-stage on the Trane website) for an additional, not insignificant, charge. This offer came about because the force of the air from the registers, when combined with the new ducting, is significant and I expressed some comfort related concern to the salesman and installers. There is no additional labor charge because the switch must be made regardless. I’m tempted but I can’t decide if the VS is worth the up charge. Just how much nicer is that 3-stage VS furnace? I’d love to list the price for this equipment upgrade but realize pricing is against the forum rules.

*Location: Southern CA
*2,500 sq ft 2-story home with high vaulted 2-story ceilings in 1/3 of downstairs.
*36x14 return downstairs and 25x14 return upstairs
*5 ton single speed 13 SEER Trane condenser, sized more for cooling

Really appreciate any and all feedback.

[keeplearnin]

You do realize that you are not buYing a car? You can't really test drive a furnace before you install it. You can research web sites that will have customer critiques and satisfaction surveys. Both Trane and carrier are very dependable brands and I don't think their will be a very big difference in your overall comfort. But at least you and the contractor came to a agreement I will commend you on that.

[big sky hvac]

Variable speed blower is definately worth the added investment. 100K BTU for Southern Cal. seems pretty extreme to me though. I have a 2600 sq. ft. tri-level home in MT and I'm going from a 100K to a 90K, modulating furnace this spring. It seems to me like that furnace is way oversized. Did anyone perform a load calc. to verify that's what size furnace you need?

[rmrc]

You do realize that you are not buYing a car? You can't really test drive a furnace before you install it.
Yeah the 120k btu XR95 was installed in error. They said if I want to go VS they have no problem installing it since the incorrect furnace has to come out. This was their unsolicited offer. Needless to say I'm very happy with their service on the mix up.

[rmrc]

Variable speed blower is definately worth the added investment. 100K BTU for Southern Cal. seems pretty extreme to me though. I have a 2600 sq. ft. tri-level home in MT and I'm going from a 100K to a 90K, modulating furnace this spring. It seems to me like that furnace is way oversized. Did anyone perform a load calc. to verify that's what size furnace you need?
The furnace is certainly more than I need but we needed the 5 ton blower and this is the lowest btu option (from what I'm told). I don't know what the 1st and 2nd stage btu ratings are but I'm thinking it would be more comfortable, quieter, and obviously more efficient than 100k single stage/speed all the time. I doubt the furnace would ever kick into the 3rd stage. Just looking for confirmation I suppose.

[acwizard]

Hi neighbor , you are in my backyard. It is possible that first stage is setup for a hybrid system, first stage heat pump, second stage low fire gas, third stage high fire gas. it has been awhile since installing a Trane furnace so I am just speculating. You probably need the airflow for cooling ,so the larger furnace is a wise choice. Unfortunenately , the heating value is way out of proportion for our climate zone. The days of forced air heating are numbered with the Title 24 and netzero homes in the upcoming future. Pushing air thru a duct is very inefficient way of transferring energy from one location to another. The ecm blower motor is the best bet for energy reduction when using a forced air system. The home must have good ductwork design to take advantage of this technology.

[rmrc]

Thanks very much for the responses. I've decided to go with the XV. Will the Honeywell Focus Pro TH6000 series t-stat work with the XV95 or will I need to upgrade that as well?

[acwizard]

The thermostat you have will work just fine.

[big sky hvac]

Thanks very much for the responses. I've decided to go with the XV. Will the Honeywell Focus Pro TH6000 series t-stat work with the XV95 or will I need to upgrade that as well?

If you're going to go with a multistage furnace, you should go with a multistage thermostat. This will help you get the most efficiency out of your new furnace. You can get the Focus Pro 6000 in a multistage, but I would recommend a Honeywell Vision Pro IAQ thermostat. Very nice touchscreen thermostat, very easy to program and only requires 3 wires in the wall. You can also use it to control a heat pump or humidifier.

[rmrc]

Thank you for the t-stat recs.

Big Sky- wouldn't the IAQ be overkill for a multistage furnace and single stage AC with no other components? Wouldn't the 8320 or 8321 be more than enough for my simple hvac setup?

[big sky hvac]

Thank you for the t-stat recs.

Big Sky- wouldn't the IAQ be overkill for a multistage furnace and single stage AC with no other components? Wouldn't the 8320 or 8321 be more than enough for my simple hvac setup?

Putting a 100K furnace in a 2500sq. ft. southern cal. house is overkill. I know why you have to, because you need a 5 ton blower for your A/C. Yes, the 8320 will work, but it depends on how many wires you have in the wall. The Vision Pro IAQ offers more flexibility because it only requires 3 wires to control everything. With the 8320, you'll need a minimum of 5, if you want it hardwired you'll need 6, if you want the outdoor temp. sensor you'll need 8. They both do the same thing, only the Vision Pro IAQ offers more options. So, to answer your question, I would say no it's not overkill at all. I install a lot of IAQ stats for multi-stage furnaces with single stage A/C's.

[acwizard]

Being that I live in southern california, homes here are not constructed the same as back east. R-13 for walls and R-30 for ceilings are the minimum. There are a million rules out here and Title 24 is extremely complicated. The average walls are constructed with R-19 and ceilings almost always have R-30. I would agree that the heating size is high but cooling is where one can get into sizing problems. The Goverment dictates everything if this is truly a new structure.

[rmrc]

big sky and acwizard-- Thank you both VERY much for your comments. Since I have the Focus Pro 6000 I'm guessing I have only three wires but I'll have to take a look when I get home. And, Big Sky brings up a very good point about skimping on the t-stat. I also like the recirculate feature of the IAQ.

My home was built in 1986 and is nowhere near as tight as the newer construction we had in WI a couple years back. My attic insulation is only the pink stuff that's 4"-6" thick at the most. By today's standards I'm sure it's horrible and at some point we will address it. So many things to do, not enough money to do them all at once. The 24 year old Carrier died so that came first.

I know the furnace is overkill for socal and this is the reason I took the dealer up on the multi-stage with VS blower upgrade. I doubt it will ever fire in the high stage but the VS blower should provide a lot more comfort than single stage/speed furnace (what I've gleaned from reading this forum). Hopefully I understood correctly.

It always sucks trying to learn something entirely new under the 12/31 time crunch for the tax credit. You guys have answered all my questions so thanks again for the help.

[big sky hvac]

big sky and acwizard-- Thank you both VERY much for your comments. Since I have the Focus Pro 6000 I'm guessing I have only three wires but I'll have to take a look when I get home. And, Big Sky brings up a very good point about skimping on the t-stat. I also like the recirculate feature of the IAQ.

My home was built in 1986 and is nowhere near as tight as the newer construction we had in WI a couple years back. My attic insulation is only the pink stuff that's 4"-6" thick at the most. By today's standards I'm sure it's horrible and at some point we will address it. So many things to do, not enough money to do them all at once. The 24 year old Carrier died so that came first.

I know the furnace is overkill for socal and this is the reason I took the dealer up on the multi-stage with VS blower upgrade. I doubt it will ever fire in the high stage but the VS blower should provide a lot more comfort than single stage/speed furnace (what I've gleaned from reading this forum). Hopefully I understood correctly.

It always sucks trying to learn something entirely new under the 12/31 time crunch for the tax credit. You guys have answered all my questions so thanks again for the help.

If you have a Focus Pro 6000, you more than likely have a minimum of 4 wires. The 8320 will provide you with the fan circ feature as well. The IAQ just offers more flexibility with more options. Another thing you may consider with having an ecm blower motor is to run the blower continously rather than periodically by using the circ. feature on the stat. It will cost you very little in electricity to operate. It will also keep your air cleaner by constantly filtering the air and will help to even the temp. out in the house and make it more evern and consistent. Another thing I would strongly recommend when you get your furnace replaced would be to go with a media style filter like an Aprilaire 2210/2410 or something similar in the 4" to 5" range. You'll be happy you did.

[rmrc]

Please bear with me on this follow-up question for a newb.

I'd like to have all the facts ahead of time so just to be clear, if I have the Trane 4TTR3060D1000AA (XR13 5 ton) do I absolutely need a 5 ton furnace for more powerful blower? :confused:

As stated earlier in the thread, the incorrect XR95 that was installed will be replaced by an XV95 and I just want to make sure that given my climate in socal I get the lowest BTU XV95 that will match up with the A/C condenser. My dealer told me there is a new 3 stage (I think ~60k, 80k, and 100k) Trane model with max 100k BTU not yet listed on the website (I don't have the model number yet). They suggested this model but I want to verify that I couldn't go with the TUH2B060A9V3VA or the TUH2B080A9V3VA. I'm assuming these two models are lower ton but don't know for sure. The coil is the 4TXCD061.

The system was designed with the emphasis on cooling so it may be that I just have to settle on an oversized furnace and make the best of the situation.

Thanks again for the help

[big sky hvac]

Please bear with me on this follow-up question for a newb.

I'd like to have all the facts ahead of time so just to be clear, if I have the Trane 4TTR3060D1000AA (XR13 5 ton) do I absolutely need a 5 ton furnace for more powerful blower? :confused:

As stated earlier in the thread, the incorrect XR95 that was installed will be replaced by an XV95 and I just want to make sure that given my climate in socal I get the lowest BTU XV95 that will match up with the A/C condenser. My dealer told me there is a new 3 stage (I think ~60k, 80k, and 100k) Trane model with max 100k BTU not yet listed on the website (I don't have the model number yet). They suggested this model but I want to verify that I couldn't go with the TUH2B060A9V3VA or the TUH2B080A9V3VA. I'm assuming these two models are lower ton but don't know for sure. The coil is the 4TXCD061.

The system was designed with the emphasis on cooling so it may be that I just have to settle on an oversized furnace and make the best of the situation.

Thanks again for the help

If you have a 5 ton A/C, you'll need a furnace with a 5 ton blower in it. Generally you require 400 cfm per ton, which means you'll need to have a furnace with a blower capable of 2000 cfm. In case you're interested, Lennox's SLP98UH090V60C is a 3-stage/modulating furnace with a 5 ton blower and has a 88K BTU input. Was a load calc. ever done to verify that you do in fact require 5 tons of cooling?

[garya505]

Was a load calc. ever done to verify that you do in fact require 5 tons of cooling?

Let me guess the answer to that one is a big fat NO.

[sktn77a]

You're stuck with a 2000CFM furnace no matter which direction your turn because of your cooling requirements. Get the smallest multistage furnace you can from Trane. It'll be oversized on heat but will be running on low most of the time. And when hell (sorry, SoCal) freezes over, you'll be all set!

;)

[rmrc]

There was no load calc performed. I know, I know...I feel stupid but not being in the HVAC business I didn't know any better and found this site too late. I had two Rheem estimates and three Trane estimates (all Trane Comfort Specialists and all NATE). Every single one recommended a 5 ton A/C condenser for my house. I went with the "experts." I'm sure 5 ton is too much but what am I to do now. All the accessible ducting was replaced and I have solid 8" and 9" ducting to the 11 registers in the house. The r-6.0 flex in the attic is larger. I don't know for certain but I'm pretty sure my ducting can flow at 2000cfm.

An update after speaking with the dealer today: The furnace to be installed is a brand new XV95 model which is not yet in production. It would make sense the model number for the 5 ton will be TUH2D100A9V5VA (I don't have the model number yet). Production is scheduled to start 7-Feb with shipment of my pre-ordered unit set for 11-Feb. This is a 2-stage furnace with nominal outputs of 61,800 and 95,000. While still more furnace than I need this is the lowest output 5 ton XV95. It should be a dramatic improvement compared to what was originally contracted for and a huge improvement over the old single stage 115k furnace that came out. We will use the HW IAQ t-stat.

Big Sky- this Lennox furnace sounds interesting. Do you think it would be significantly better than the above mentioned Trane? Since the Trane is on order I do have time to switch things up but I'm assuming the coil would need to change too? And another concern that tigerdunes brought up is his concern that the 4TXCD061 they installed is not a match for the new XV95/XR13 combo....

[acwizard]

The first concern would be your ductwork, even with 11 8" or 9" that doesn't seem like any real thought went into the design. What about the return. The coil and equipment selection should be fine. How large is your home and what locality in So. Calif. Typical rule of thumb use to be 400 sq. feet / ton. Sizing can range anywhere from 300 sq. feet per ton up to 600 sq. feet/ton. Without an accurate load calculation, how good are you at guessing. You would be surprised at how far off you could be. Just the other day, a contractor (hvac) called me concerning a custom house in the Hollywood Hills, regarding a cooling problem with the master bedroom area. This home is 10,000 sq. feet, 2 levels, lots of glass, installed tonnage 24.5 tons. One would think that would be enough. We ran a calculation on just the glass in the area of complaint. The house is shy between 3 and 4 tons , just to maintain a comfort level in August and September. The ductwork is a disaster. Our plan is to demo the entire ceiling on the upper level, add soffitts,and redistribute the air where it really needed. My point I am trying to make is do it right, this is a major investment to your home.

[rmrc]

acwizard-

The returns are 36x14 downstairs and 25x14 upstairs. Home is slightly over 2500 sq ft with two story ceilings in ½ the downstairs and located in Tustin. Home faces S-SW (15 of 27 windows facing this direction) with larger windows and a lot of afternoon sun and basically no shading. During July-Sept my white/blue bottom pool will routinely reach 86+ degrees with no heating. A lot of sun. Did the dealer size my A/C properly without a load calc...I won't know until July-Sept rolls around. But again, all five that came out said 5 ton. Yeah, I know, how do they know without a load calc. I guess it's just that..a guess on their part :mad:.

At the time I did everything I knew to do before signing with the dealer. I checked the BBB which is an A+ rating, called the state licensing board, and the company has been in business since 1993. All checked out perfect. Had I known what a Load Calc was I would have required one before signing. Amazing that none of the five that came over performed a load calc.

The company is being great about correcting their install error and I’m glad they offered me the option of a VS furnace since the one they installed had to come out anyway.

Since I’m not in the hvac business I can’t comment on the install or ducting but the third party HERS rater who came over volunteered that it was a “very nice install with nice ducting.” I’ll take his word for it and agree that all looks very good to my untrained eye. The airflow in the home is infinitely better than before the work.

The new furnace on low fire has an output of over 30k btu less than the old single stage 115k furnace it’s replacing. When combined with the new duct work I’m hopeful it will provide a lot more comfort and lower bills from the gas and electric companies.

All the input is greatly appreciated.

[acwizard]

I would have sized your unit the same , with the information given. I live in Orange County as well. 5 tons is the largest residential unit, and you definately would not have wanted to go smaller with the square footage of your home. Being your system is inspected and required a hers rater, rest assured that your system will operate as efficient as required by Calif. Tiltle 24 requirements.

[garya505]

If I had to put a grossly oversized furnace to get a 5-ton blower, I'd put in something that could modulate (or stage) down to 35%.