Need help with final decision

[Zomby]

Well, the Bryant contractor says he is afraid to put a 2 ton in because he fears I will come back on them if the system doesn't cool the way I want it to. I am so damn frustrated right now I could spit nails. I think I am just going to put something in here and say screw it because no matter what I do, I have a feeling it will be wrong.

[RyanHughes]

What about the Trane dealer who is confident in his calculation for a 2 ton system? There is a science behind sizing HVAC equipment. It takes time to find a contractor who will size the equipment properly and perform a proper load calculation. I can see how it can be frustrating on your end. I can tell you that for a 1500 sqft house, I would 'fear' putting in a 3 ton system.

[Zomby]

What about the Trane dealer who is confident in his calculation for a 2 ton system? There is a science behind sizing HVAC equipment. It takes time to find a contractor who will size the equipment properly and perform a proper load calculation. I can see how it can be frustrating on your end. I can tell you that for a 1500 sqft house, I would 'fear' putting in a 3 ton system.

I hear ya. But what I fear is my wife complaining next summer "if" the house isn't cooling and I can't tell her that it isn't the contractors fault, it was mine because I was the one who downsized the AC unit...LOL!

You know what? I came here asking you fine folks for advice and most all of you have said to go with the 2 ton/2 stage unit. The Trane guy was adamant about a 2 ton/single stage. The American Standard and this Bryant guy recommended 2.5 tons - NOT 3 tons. The only reason he went to 3 ton is because the 127A Preferred does not come in 1/2 ton sizes.

Like mentioned above, I bet he upsized instead of downsized because that is kind of the way a lot of guys do.

I am 90% leaning towards the 2 ton/2 stage...... Just need another push I guess.

Thanks!

[54regcab]

The cost difference between the 2 ton and the 3 ton is $600.

Compare the cost difference between the 2 ton single stage and the 3 ton 2 stage.

[54regcab]

Compare the cost difference between the 2 ton single stage and the 3 ton 2 stage.

IMHO the 2 stage 2 ton won't have a decent payback time vs, a single stage 2 ton unless large rebates are absorbing much of the cost difference. When you're at 750 sqft per ton you won't feel a large blast of cold air like you do at 500sqft per ton.

[Zomby]

Compare the cost difference between the 2 ton single stage and the 3 ton 2 stage.

The cost difference between the 2 ton single stage and the 3 ton/2 stage is around $600. He lowered the cost significantly by adding a discount.

IMHO the 2 stage 2 ton won't have a decent payback time vs, a single stage 2 ton unless large rebates are absorbing much of the cost difference. When you're at 750 sqft per ton you won't feel a large blast of cold air like you do at 500sqft per ton.

I am thinking if I can get a return on my money in 10 years, I'll be happy.

[RyanHughes]

I wouldn't go to a 3 ton 2-stage in your home in my opinion. I haven't looked at the most recent ratings of Carrier/Bryant 2-stage unloading scroll systems, but I know they can run as much as 75-80% capacity on low stage. That puts you at 2.2-2.4 tons on low. Might as well get a single stage 2.5 ton system if you don't feel comfortable with getting a 2 ton system, which may very well be all you need. Trane used to make a 2.5 ton 2 stage system back when they made the XL19i (R-22) -- now just 2,3,4,5 ton in their XL16i and XL20i. If your home's load is 2 tons, then a 2-stage 2 ton system would be great. You would achieve longer runtimes on the milder days to improve comfort and dehumidification vs. a single stage system. You need a contractor confident and thorough in his load calculation such that he can guarantee the system will maintain your desired indoor temperature at design conditions. Will the Trane guy guarantee performance of the new system? He should. Find out what design conditions he used (indoor and outdoor temps, winter and summer).

[Zomby]

I wouldn't go to a 3 ton 2-stage in your home in my opinion. I haven't looked at the most recent ratings of Carrier/Bryant 2-stage unloading scroll systems, but I know they can run as much as 75-80% capacity on low stage. That puts you at 2.2-2.4 tons on low. Might as well get a single stage 2.5 ton system if you don't feel comfortable with getting a 2 ton system, which may very well be all you need. Trane used to make a 2.5 ton 2 stage system back when they made the XL19i (R-22) -- now just 2,3,4,5 ton in their XL16i and XL20i. If your home's load is 2 tons, then a 2-stage 2 ton system would be great. You would achieve longer runtimes on the milder days to improve comfort and dehumidification vs. a single stage system. You need a contractor confident and thorough in his load calculation such that he can guarantee the system will maintain your desired indoor temperature at design conditions. Will the Trane guy guarantee performance of the new system? He should. Find out what design conditions he used (indoor and outdoor temps, winter and summer).

Bryant does offer a 2.5 ton single stage in their legacy line. I didn't like the design because it does not have a louvered cabinet. We got hit with 4 hail storm this past year and each one dented the hell out of the coils on the condenser unit.

I have decided to go with the 2 ton unit. I am basing this on what the contractors said on their initial visits as they all suggested 2.5 or less, but also on what information I have gathered from this post as well as digging through the archives here.

Once the decision is made, I am stuck with it either way!

[54regcab]

If it makes you feel any better I made the switch to a 2 ton from a previously installed 3 ton and feel it was right on the money !!!

[jtrammel]

I think you and your wife will be happy with that decision and happier with your utility bills

[Zomby]

A funny thing happened on the way to being "final".

The Bryant rep asked me if the Trane rep knew my ductwork was in the crawlspace. I told him I really didn't know and asked him why. He said the reason he went 3 ton was because of that fact.

So I call the Trane rep and he said he did not factor that in his calculations and then suggested a 2.5 ton or perhaps a 3 ton if I went to a 2 stage.

I should have quit while I was ahead........ Sheez.

[tedkidd]

You can always take the savings and get a rolling window unit IF it doesn't keep up for that 1 week a year.

[dan sw fl]

I have decided to go with the 2 ton unit. I am basing this on what the contractors said on their initial visits as they all suggested 2.5 or less, but also on what information I have gathered from this post as well as digging through the archives here.

Once the decision is made, I am stuck with it either way!

How many automobiles do you review when you are about to buy a car?
There must be 200 models now with 20+ options providing for 10,000's of options.

Apparently, it may take years for one to decide whether a 4 or 6 cylinder is optimum for the next 15 years.
After all, one only needs a 4 cylinder if there is a driver and 2 passengers are riding.
However, it's not going to work optimally when there are a total of four people riding in the mountains.
Of course, out of 200,000 miles one might drive in ~15 years,
the extreme case of an engine being 'maxxed out' may only apply for 3,000 miles / < 2% of the time.

I guess going 59 MPH instead of 66 MPH for a total of 50 hours in 15 years is going to be an interesting dilemna to face
when one tries to determine which of 10,000's various auto characteristics permutations one might foresee
in selecting that efficient, favorite brand, optimum vehicle.

I'd buy that comfort machine that's going to satisfy me > 96% of the time/ a.k.a. 2,880 hours out of 3,000 "summer time hours"
and be prepared to enjoy the temperature over 79'F inside for ~120 hours a year when it might be > 99'F outside.
Of course, I'll probably be working, visiting, shopping, in the pool, at the beach or at the movies half that time,
so I won't even notice the 80'F inside for 60 hours of the total.
And if my $30 fan doesn't satisfy me with a little more cooling,
I can always go to the bar and talk about my dilemna.

[54regcab]

Don't forget Man J also includes certain internal gains. Those appliances can be switched off for a few hours during the 2% of the summer.

[tedkidd]

Lol

Dan funny Dam.

Hey, don't forget the 240 light load hours that your smaller unit actually makes your home MORE comfortable than the oversized unit would. and all that dough in your pocket from equipment and energy savings!

[Shophound]

Dan is correct. The only time a "right sized" or slightly undersized system might deliver a lack of complete comfort is during the worst days of the year, which in comparison to the entire year cooling requirement is a small amount of time.

Even those "worst day" events could be narrowed a bit by paying attention to the house building envelope, such as insulation levels, radiant barrier or "cool roof" options, air sealing, etc.

[tedkidd]

Dan is correct. The only time a "right sized" or slightly undersized system might deliver a lack of complete comfort is during the worst days of the year, which in comparison to the entire year cooling requirement is a small amount of time.

Even those "worst day" events could be narrowed a bit by paying attention to the house building envelope, such as insulation levels, radiant barrier or "cool roof" options, air sealing, etc.

They could be further narrowed by dropping the tstat setting a few degrees in advance of the weather events - kind of like gaining speed before going over a hill.

On Monday when you see it's going to be 101f on Friday, move the thermostat from 75 to 72 and pull some BTU out of the house's mass.

[Bsmith816]

First, thanks to everyone who has helped me get to this point. Your knowledge and assistance has been extremely helpful!

I have narrowed it down to Trane or Bryant and would appreciate your thoughts on the 2 systems.

My hose is as follows:

1,500 s/f single-story ranch over a crawlspace.
Mid Missouri
3 ton condenser - 9 SEER
75,000 btu gas furnace

Trane contractor suggested the following:

XR15 2-ton single stage condenser - 16 SEER
XV95 2-stage, variable speed gas furnace
"matching coil"
TCONT thermostat

Bryant contractor suggested the following:

127A 3-ton two stage condenser - 16.5 SEER
96T 2-stage, variable speed gas furnace
CNPV*3717A** indoor coil
T6 Thermostat


As you can see the biggest difference I see if the condenser unit. Trane being 2 ton single stage and Bryant being 3 ton two stage. The Bryant contractor said a 3 ton two stage would serve me much better than a 2 ton single stage.....

As far as I know, they both did pretty much the same load calculations.

Any thoughts would be more than appreciated!

You should have gone with the 3ton two stage. If you have 1500 square feet that two ton will have trouble keeping you cool if the temps in the summer get too extreme. You can never predict what the summer temps will bring. However you can have the equipment that will be able to handle what mother nature brings. If you are already spending the money you should spend money that is going to make you comfortable. Most home owners dont like to spend their money on HVAC equipment but have no problem buying a 3000 flat screen TV. Your money well spent would have been the bigger unit. Saving a little bit of money now isnt going to matter when it is 95 degrees outside for a month straight.

[Shophound]

They could be further narrowed by dropping the tstat setting a few degrees in advance of the weather events - kind of like gaining speed before going over a hill.

On Monday when you see it's going to be 101f on Friday, move the thermostat from 75 to 72 and pull some BTU out of the house's mass.

That is somewhat of a change from your more "steady state" thinking regarding tstat settings. To me, lowering the interior air temperature ahead of a 101 degree high temp day will only accelerate the rate of heat gain through the envelope, even before the daily high is reached. You may be "pulling BTUs out of the house mass", but you are also accelerating the rate at which those extracted BTUs are replenished to the envelope from outdoors. The greater delta that may exist between two states, the more force will be present seeking equilibrium.

I am of increasing persuasion that the real mastery of "passive house" thermal envelope strategy is what I might deem "modulation of the thermal flywheel effect". IOW, in summer, for example, the house interior is not being blasted with heat gain even before peak solar loading occurs. Furthermore, by the time peak inward heat migration does occur, exterior conditions ate already setting up to slow or reverse the flow of heat through the envelope, such as night sky radiant cooling, etc.

[hkempf]

i like bryant myself but thats a ford chevy conversation in my opinion, they both do the job