Carrier Infinity 96 good to go?

Reply

  #1  
Old 12-14-16, 07:20 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
Carrier Infinity 96 good to go?

After 23 years with my lovely Bryant 90% furnace I'm at a crossroad. Something breaks nearly every year and this time the blower has gone out--and I already replaced the motor last year.
I'm being pitched a Carrier Infinity 96 (model 50TN6) 100KBTU as replacement in my 1900ft^2 home.

Any known problems or concerns with this brand/model?
Are Carrier furnaces made in the USA?
 
Sponsored Links
  #2  
Old 12-14-16, 12:16 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
I would be concerned about the sizing.

Unless this house has zero insulation and single pane windows 100k is excessive. The ducts in this house are unlikely to be large enough relative to the amount of air this furnace will try to move.

You may only need 60k input, or maybe 80k if the house is poorly insulated.

A space heater puts out 5000 btu/hr on high. A 100k furnace with 95k heat output is 19 space heaters running on high.

I sure as hell hope your 1900 sq ft house doesn't need 19 space heaters to stay warm.

If you oversize a 2-stage or modulating furnace, you completely lose the benefit. It will still cycle on and off a lot like a less expensive properly sized single stage would.

I would also be concerned about the cost of replacement parts with the infinity. It has an ecm vent motor and blower, expensive circuit boards too.

It's a premium furnace and there are less expensive models that will work fine if sized and installed right. A premium unit is only as good as the installer though -> if it's installed the same way as a builder's unit, not sized right, controlled by a single stage thermostat and left at factory settings, you won't see much benefit.

Key is fining a contractor who will do things right and not just slap the unit in and leave.

Do you need 2-stage heat? It's nice to have, especially if furnace isn't oversized and staging is done by the thermostat, not a timer.

Do you run your fan continuously? If not, the ecm motor may not pay off. These motors have a lot of other advantages like compensating for ductwork and slowing down to dehumidify in a/c mode.

But they're very expensive to repair; if the motor and it's control module go out you could be out $1000. A lot of techs may not have the skill to properly diagnose these furnaces and will just change out parts.

You can get 2-stage with a conventional motor which costs much less to replace if it goes. Trane/american standard, rheem, and york still offer them.

Where are you located? decribe the house -> 2x4, 2x6 with brick veneer or siding or stucco, or brick structure? Insulated walls? attic? basement? number of stories? are the ducts in a basement or unconditioned space?
 
  #3  
Old 12-14-16, 12:21 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
Are Carrier furnaces made in the USA?
they've been trying to move production to mexico. reached a deal with trump to keep some jobs in the us in exchange for tax advantages. the company that owns carrier has a lot of defense contracts with the us government which they could have lost.

lennox and rheem make a lot of their stuff in mexico. actually rheem is 100% mexico.
 
  #4  
Old 12-14-16, 06:41 PM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
guy48065

Disappointing to hear. Job is done. I had to decide fast--it's 0f. outside today and I really didn't want to keep relying on this patch job to keep warm:


I probably paid too much but even though the Bryant was a POS I kept it going for 23 years. Maybe this Carrier won't be as troublesome.
 
  #5  
Old 12-14-16, 07:30 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
So you got the 100k btu unit? i hope that you have large ducts.

bryant and carrier are the same. i don't think your old unit was a pos and neither is the new one a pos, it's possible that there were issues with the original install or ducts which shortened it's life.
 
  #6  
Old 12-14-16, 07:40 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
  #7  
Old 12-14-16, 07:43 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
Please post a picture of the new install
 
  #8  
Old 12-15-16, 05:58 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
Please post a picture of the new install
What are you looking to see? It looks just like the old install except shorter, with a little darker paint.
...And of course the "Red Green-inspired" piggyback blower, duct tape & cardboard that got me through the night is all gone ;-)
 
  #9  
Old 12-15-16, 06:31 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
Do you want the long version??

Originally Posted by Muggle
...it's possible that there were issues with the original install or ducts which shortened it's life.
Originally Posted by Guy48065
...even though the Bryant was a POS I kept it going for 23 years.
Is 23 years considered a short life for a furnace? *I* would say yes but most the advice I read here is that it was way past due for replacement. My main issues were with the original installer that did nothing to match the furnace to the house. In 1993 they pulled out a 20 year old 100Kbtu oil burner and slid a 100K 90% NG unit in its place. No calculator involved. The previous owner had made changes to the floor plan which eliminated 2 hot outlets and 3 cold returns. You see the same thing on all the home improvement shows on cable--but they never show the rest of the story. I've had to deal with flow and balance issues since. The installers have been out numerous times, during the warranty and beyond, performing such clever "fixes" as opening up my basement outlets and cutting a big hole in the cold return right before the filter box. I removed my old SS chimney and used the chase as a cold return shaft for 2 of the 3 bedrooms affected by the removal of the wall on the 1st floor.
The Bryant has been short-cycling & hitting the high limit for 20 years but still soldiered on needing only the occasional ignitor. Also the various mfr. recall items like the controller board (2 different versions) and inducer assembly. Do I really consider it a POS? Maybe not but any furnace model involved in a class action lawsuit for bad heat exchangers doesn't deserve a recommendation, either. Ultimately that's what did it in. The blower quit but when I investigated that problem I found water on the floor under the cabinet. The HVAC company I had out verified the bad blower motor--and a cracked heat exchanger. I didn't feel it was worth sinking $1500 into fixing those 2 problems.

The salesman told me the variable speed blower on my new furnace will adjust to compensate for the flow problems and maintain correct static pressure in the airstream. I hope he wasn't snowing me or I'm going to have to assume ALL HVAC people are scammers.
 
  #10  
Old 12-15-16, 06:50 AM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
The variable speed motors will not like inadequate duct, and depending how poorly the duct is done it will have a high failure rate.
 
  #11  
Old 12-15-16, 11:12 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
How do I verify duct adequacy? I'm sure a pro doesn't just eyeball it.
 
  #12  
Old 12-15-16, 01:12 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
Delta temps across the unit, static pressure readings and CFM calculations.
Of course the real way to do things is to start with a manual s, manual j and manual D. But this is to be done before any equipment is even purchased.
Equipment sizing is very important. It's one of the leading causes of equipment performance and reliability. Bigger is most definitely not better.
 
  #13  
Old 12-15-16, 01:46 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
So did they give you a new 100k btu furnace or downsize?

hopefully the new furnace is smaller.

100k really is huge for residential.

otherwise you just got stuck with an expensive single stage furnace. if a two-stage thermostat is used it will not hit high if it's 100k btu.

the blower motor's controller may suffer an early death.
 
  #14  
Old 12-15-16, 04:41 PM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
Thanks for making my day brighter guys. As if I wasn't feeling crappy enough shelling out $4000 I don't have to these predators.
 

Last edited by guy48065; 12-15-16 at 05:01 PM.
  #15  
Old 12-15-16, 04:49 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
We aren't trying to put you down at all. But buying HVAC equipment is way different then buying most any other appliances. The hvac system has to be put together on site, sized by someone in the field and otherwise has a lot of hands involved between when it leaves the factory to when the install is done. The installer is the most important thing to consider.
 
  #16  
Old 12-15-16, 05:04 PM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
You're making it sound like I went "shopping" for a furnace and chose the wrong one.
I put my trust in experts to sell me the right replacement in an emergency situation.
 
  #17  
Old 12-15-16, 05:52 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
The sad reality is that you can't trust the experts. they'll do what suits them best. it's not your fault.

most will never downsize a furnace out of fear of getting complaints. this is in spite of the fact that airflow requirements have changed and it's the output that counts.

if there's a 100k 80% oil furnace, 80k 96% would be just about the same output. now if the 100k 80% was oversized they should have gone for 60k.

There's also the issue of width. They'll put a bigger, wider furnace than optimal so the metal transition to the plenum is less work.

To top if off they'll take a 2-stage furnace and set it to run on a timer, so it runs on high when not needed rather than if it's not keepup up on low.

the 2-stage is more expensive so if they mark it up by a percentage, they make more profit with a more expensive furnace when it's not necessarily what you needed.

it takes time and hence money to do measurements and properly size, the contractor would charge hundreds extra, then lose the bid.

high end equipment like what you got + bad sizing/install = substandard performance.

could get good results for less money with a smaller single stage.

it's sad when homeowners are ripped off and worse if the money was borrowed.
 
  #18  
Old 12-15-16, 06:44 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
To put it in perspective, my house is 3100 sq ft and has a single 125,000 BTU 90% furnace. I've run some calculations and according to my math I can meet my heat loss at average winter temps with a smaller furnace, which is what I'll do when I switch it out. And it'll cost less and save me money on utilities
 
  #19  
Old 12-15-16, 06:53 PM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
I CAN say this: This furnace is quiet, cycles far less, and isn't bouncing off the high limit. I'm running the fan full time and can't even hear it.
23 years ago one upgrade I requested was a 2" filter box. That furnace never could run with a 2" filter--it restricted the flow too much and ran too hot. I had to install an electronic cleaner--which didn't perform well.

THIS furnace has a 5" filter and it actually works.

I'm hoping the "backseat engineering" is off the mark because this one behaves like it's supposed to.
 
  #20  
Old 12-15-16, 07:13 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
that's because it's 2-stage and low needs less airflow.

it's a a big improvement over a 100k input single stage for sure, it's like having a 60 to 70k single stage.

you don't get the full benefit if it's too big. it would run even longer cycles and be quieter if appropriately sized.

hope they put either an infinity control or regular 2-stage stat to keep it off high in all but the most extreme weather conditions.
 
  #21  
Old 12-15-16, 07:52 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
Post some pictures of the install
 
  #22  
Old 12-16-16, 07:06 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
Originally Posted by roughneck77
Post some pictures of the install
If you had responded to post #8 I could have but now all the stuff that was in that part of the basement is moved back in place. If you're wanting pictures of the ductwork I can maybe do that but most of it is on the other side of a wall the furnace is next to.
 
  #23  
Old 12-16-16, 07:16 AM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
Ductwork and unit. Pictures are worth a thousand words.
The unit has a minimum distance to combustibles so items cannot be stored right around it.
 
  #24  
Old 12-16-16, 02:54 PM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
I don't know what you can tell from these.





 
  #25  
Old 12-16-16, 04:40 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
Question:

Do you have a natural draft water heater? pilot ignition venting into metal pipe with drafthood?

If yes, it's very unsafe to have a return air vent in the same area.

The return drop is very sloppy and small. I don't know if that was there before or they modified it to put the new furnace.

Most if it looks undersized - they put a transition to the correct size for the filter opening rather than putting the proper size drop.

I would want at least a 24 x 12" drop.

That may have contributed to the old unit cycling on limit and will contribute to higher than necessary electric consumption with the variable speed ecm blower.

Otherwise it looks okay but i can't comment on duct sizing. we don't know the sizes.

Doubt the ducts are actually sized large enough for 100k furnace.
 
  #26  
Old 12-17-16, 10:43 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
That return duct hasn't changed in the 23 years we've lived here. All ducts are original to the original 100k oil burner
The filter box has always been the same dimensions--it's just gotten wider as media choices have changed.
Any transitions that have been made were to adapt shrinking furnaces to my bonnet.
 
  #27  
Old 12-17-16, 08:18 PM
Member
Join Date: Oct 2014
Location: usa
Posts: 4
Received 0 Votes on 0 Posts
THANKS for the interesting information about Bryant/Carrier

I have been shopping for a furnace and A/C and was leaning towards an Infinity, ...Carrier (was very happy to know they are not moving to Mexico)
I think you got a good price and made it for the 150 dollar tax credit, right?

propane (so only Com Ed rebate) vs. Nicor rebate

I got a bid of about 13,000 for furnace and A/c, Reme Halo UV about 1500 of that...and a merv 15 filter, off the top of my head. A humidifier and this, I was given 3 levels of systems...and this one would be 97% (previously had 120,000 Btus, 90 percent). He quoted for same btus...wifi thermostat...

I read somewhere that utilizing a company that also does industrial, is good and this place has union workers and the salesman said the least experienced is 10 years...ALSO the local community college hvac instructor recommended them, they have been in business (not same owners) for more than 50 years. I checked www.bbb.org and there were no big complaints, actually no reviews at all.

I do not know if they planned on coming to measure windows and so forth that a radio personality told me when I asked him what to do....have not gotten that far (I have a few things to move!! three households of stuff crammed here)

I was hoping to replace before the end of the year for the tax credit but it's not looking good with all the holidays coming up.

We built this brick ranch, 2564 square foot, half finished basement, in 1990, so we got 26 years out of it...in 2010 paid for igniter, a couple control boards due to hvac student friend experimenting...(about 1000 for all)...and lately I decided to get new system because for a couple weeks every day I had to restart the furnace.

Finally I saw on youtube the importance of cleaning the flame sensor (and my friend from hvac school said the base also had a lot of rust he cleaned off)....the youtube guy said he has only replaced one or two flame sensors, but he always cleans them during a service call due to the importance of such..

and it's been going nonstop for 3 weeks as of yesterday since we cleaned the flame sensor..

I also hope to find on here more info on the air cleaners. I rescue cats and dogs and have no sense of smell so it would seem like heaven to have a blower working 24/7 to do fresh air./purifying (I was told the reme halo uv is enclosed and will not hurt furnace parts)

Another question, I heat my 3 car garage, but the utility room linked to it before the kitchen door has no cold air return so it is always chilly in that room and also the kitchen...which is okay...but is there a solution to that.? (Dog doors contribute to the cold drafts) (I highly recommend Solo pet doors, bTW) the other white one is junk cuz the collar things have batteries that die....solo uses any magnet)

Is there a reason there is no cold air return in the adjoining room to an attached garage?

Thanks for all the brain work, it's very interesting!!

For bids I sent photos of the ac/ outside (York), and we have a York Stellar PLus furnace.1990 90%

I had got bids on lennox and trane so far...and waiting for another Lennox bid since before Thanksgiving so I take it he's not interested in my business.

I paid $35 for digital consumer reports but they did not tell about air filters or the reme halo UV light...they did have a 2014 chart showing Trane Lennox and Carrier at the top for least repairs and YORK the lowest (I believe that!). 8-)

ON Amazon reviews someone said that a wifi thermostat like Honeywell would be hard on the furnace running more because it is constantly trying to be right on the dot with the temperature, I have no idea how true that is.
The radio station sent me a free Aprilaire programmable wifi thermostat 8476W but I assume I'll have to sell it on ebay as this is not the kind they had suggested in the bid.

This is like a car, if you think it only costs ~3000 a year....more or less, so what?

I don't know why a furnace is such a big deal, but it is.8-) We hate messing with our heating chances! and utilities bills.....

MY 2nd house I got ripped off...the local guy spent 6 hours twiddling around, charged me for a new control board and it cost 1400 dollars..........a 10 year old furnace........I looked up the control board cost it was 200 and he charged me like 800...I wrote to him asking that it must have been a mistake with an SASE envelope for a refund and I got no answer at all!!

I just want to do it right...we installed a Heil at my grandmas house and after 2 years something went wrong...under warranty the local guy charged 170 to re do the pvc drainage pipes....I was told the serviceman had another story from what the tenant told me, so...now I don't trust them and I do want the best furnace I can get...

On another note I once saw at a farm show an outdoor furnace that heated sheds with cow manure. I would so love to have a system as a backup ...using my cat wood pellet litter! I buy a pallet of wood pellets a year at least..8_)
 

Last edited by kitkathouse; 12-17-16 at 09:10 PM.
  #28  
Old 12-17-16, 09:11 PM
Member
Join Date: Oct 2014
Location: usa
Posts: 4
Received 0 Votes on 0 Posts
Thanks for all your information and photos. I do think you paid a fair price. 8-) According to what bids I have gotten. 8-)
 
  #29  
Old 12-18-16, 07:33 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
That return duct hasn't changed in the 23 years we've lived here. All ducts are original to the original 100k oil burner
The filter box has always been the same dimensions--it's just gotten wider as media choices have changed.
Any transitions that have been made were to adapt shrinking furnaces to my bonnet.
Well, the small return drop definitely contributed to the limit tripping on such a big furnace and having return air grill right beside the furnace is dangerous with any atmospheric combustion appliances there.

A good contractor would have insisted on fixing that.

The drop should be the length of the filter.
 
  #30  
Old 12-18-16, 07:37 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
kitkathouse - start a new thread.
 
  #31  
Old 12-18-16, 09:19 PM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
Problem is there is a rather large BTU difference between a 100k oil furnace and a 100k 90%+ gas furnace. Output is much higher on the high efficiency furnace. Needs much more airflow
 
  #32  
Old 12-19-16, 05:02 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
guy48065

How much more?

.
 
  #33  
Old 12-19-16, 05:33 AM
Member
Join Date: Oct 2016
Posts: 1,316
Received 33 Votes on 30 Posts
Depends on the furnace. You can get a basic idea on how low airflow is by testing the temperature rise across the furnace. The data tag will have a maximum allowed temp rise listed.
 
  #34  
Old 12-19-16, 06:52 AM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
Be more precise--temperature probe location & insertion depth.

On a variable speed blower 2-stage furnace wouldn't the board just speed up the blower to stay within operational limits?
 
  #35  
Old 12-19-16, 02:40 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
Yes it would speed up the blower, to an extent.

uses more electricity and is harder on the machine.
 
  #36  
Old 12-19-16, 03:15 PM
Member
Thread Starter
Join Date: Nov 2007
Location: MI
Posts: 2,612
Received 0 Votes on 0 Posts
guy48065

Be more precise--temperature probe location & insertion depth.
I measure 60* rise but I don't know if I'm doing it right.

How is it "harder" on the machine if it's running within limits? If anything--i thought by restricting the flow through a fan you reduce the amount of work it can do, which lowers the current and makes it "easier" on the fan. Just talking about the fan here since you said it will die prematurely.

Where are the usual guys (you know who you are) who are so good at explaining this stuff?
 
  #37  
Old 12-19-16, 07:22 PM
user 10's Avatar
Member
Join Date: Mar 2004
Location: NA
Posts: 1,936
Received 28 Votes on 23 Posts
Everything you said about fans is true for regular blower motors.

The motor in your furnace is microprocessor controlled with feedback from the windings.

The controller knows the cfm based on electrical feedback (back emf is right name) from the windings will raise or lower the rpm to deliver rated airflow.

If you have a really dirty filter and pull it out with the blower on, you'll hear it slow down.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: