Advice Concerning 2 System Install Estimates

[rileyrr]

We have decided to replace our Central Air Unit (Chrysler AirTemp), A-Coil (Chrysler), and Gas Furnace (old). We have had 2 Carrier installers out to estimate our needs and are looking at the Infinity Line of products (38TDB A/C and 58MVP furnace). FYI we are located outside of Philly, 2 story colonial, ~2500 sq ft.

So Installer #1 came and did a complete walkthrough of the house, noting all vent locations, taking measurements of our existing duct work, etc. He provided a cooling load estimate of 40000 Btuh and heating load estimate of 80000 Btuh, using a Manual-J calculation (excuse my ignorance if this is not the correct "lingo").

Installer #2 came and looked at our exterior A/C unit and our interior furnace, took no measurements nor looked at our existing vents. He provided no cooling or heating load estimates in his write-up.

Here are what the 2 recommended:

Installer #1: 58MVP-080 (80000 Btuh), 38TDB-048 (48000 Btuh)
Installer #2: 58MVP-100 (100000 Btuh), 38TDB-036 (36000 Btuh)

Now, Installer #2 did mention that he likes to "go one size bigger" on the 2-stage furnaces so that only in extreme weather situations will the furnace move to the higher speed.

Installer #1 offers a 10 year parts/labor warranty versus 5 year part/labor for Installer #2. If I assume that cost difference is ~$500 and that the difference in combined equipment prices is ~$700 (I think the +/- price in equipment works out to the Installer #1 equipment being more expensive), there is only about a $220 difference in price between the 2 Installers.

I am looking for some advice on the proposed systems and the logic behind Installer #2's choice of furnace. Also, is the 10 year parts/labor that important?

Thanks.

[hoos1erbud]

Hmmm...seems like you were more comfortable with the first guy. Maybe you should go with him.

Also, although I'm no expert, I know on my recent HVAC purchase the extended warantee was an optional deal offered by the manufacturer at an extra cost AND it was only available if you got the unit from someone that was up to speed on how to put it in...so...if the 1st guy is offering you that...I'd take that as a good sign.

I have no idea if it's a good deal or not. I assume they make some money on the extended warantee. I also assume it might be really nice to have if your blower motor went out during year 6. If I were you I'd call "Guy 1" back and have him quote it without the extended warantee. That'll give you an apples to apples comparison and let you know exactly what the extra warantee is costing you.

Good luck.

Phil

[rileyrr]

You are correct in that I did like the first installer the best. I just want to understand the differences between the two (pro/con) and logic behind them. Neither my wife nor I knew what to expect (price-wise) and are somewhat sticker-shocked. But, given the age of our current equipment (translation: inefficient), it is probably best in the long run that we bite-the-bullet now.

[rileyrr]

One follow-up question. How necessary is a whole-house humidifier? Is it easy to add at a later date?

Thanks.

[wyounger]

It sounds like #1 is the technically savvy pro, and did his homework. He probably also measured room sizes and window dimensions, right? I'd say give him the job, and you shouldn't have any regrets. You're amazingly lucky to have had somebody come out and do a full Manual J calculation on the first try. Usually you have to call a half dozen hacks before you get lucky and find somebody good.

If sticker shock is hurting that much, you might consider a single-speed AC instead of two-speed. If you're getting an MVP furnace, make sure they include the Infinity control. If you want even temperatures between the two floors with a single system, you're going to need zone control. If that's already in the bid, I'm not surprised you're having some sticker shock. If you get it, you'll be thrilled with the results, though. The Infinity zoning system is amazing. Even without zoning, though, these bids probably should be expensive; you're looking at top of the line equipment.

There's a lot of peace of mind in a ten year warranty, and it sounds like overall there isn't a major price difference.

The house will be just as dry in the winter with the new system as it was with the old. They aren't necessary, but adding some humidity to what used to be a crackly-dry house in the winter makes a lot of difference in comfort. If the house is really well sealed up, though, it may not be dry to start with. They can usually be installed later without much difficulty, so if there's any question that you might want one, make sure the contractor is aware that you may want to add it down the road and they can make sure to install things in such a way that there will be space for one later.

[Edited by wyounger on 06-23-2005 at 11:24 AM]

[travisfl]

Originally posted by rileyrr
Neither my wife nor I knew what to expect (price-wise) and are somewhat sticker-shocked.

For your location and application the Infinity series is probably overkill. I'd consider a 14 SEER A/C instead of the 18 SEER Infinity. Check other first tier brands, too - consider American Standard's Allegiance 14 paired with either an 80% or 90% variable speed furnace for an example.

[dash]

First go with #1,he earned the sale ,by doing it right.


Second I'd go with the two speed ,it provides the Best in indoor comfort,be sure the Infinity control is included.

[rileyrr]

Thanks for all the helpful comments. The Infinity Control is included. We also received estimates for the performance series which dropped the price a bit. But, considering we will most likely be in the house a long time, the difference between the Infinity and Performance should be made up over time in efficiency savings.

So, in general, is there a rule of thumb for what tonage to go with when the cooling/heating estimates fall in between sizes? For us, our cooling needs fall between 3 and 4, with the first installer choosing the 4 and the second choosing the 3 (since the second did not take any measurements maybe he didn't realize where it fell anyway). I am curious if the choice on the heating side of things depends on if you are using a 2-stage furnace or not.

Regarding the zoning, we thought about doing that (since our upstairs has generally been 8-10 degrees warmer in the summer). But it was going to require some tearing up of our finished basement (with drop ceiling) to install the motorized dampers. The first installer recommended running our fan on the "On" position all the time (instead of "Auto") and that alone has brought the temp difference between floors to within 3-4 degrees with our current system. So, I think this approach will be good enough for us.

Thanks.

[travisfl]

Originally posted by rileyrr
But, considering we will most likely be in the house a long time, the difference between the Infinity and Performance should be made up over time in efficiency savings.

Run the numbers yourself and see. In Florida, anything over 13.0 SEER won't pay for itself during the expected 15 year lifespan of the system. And that is with a long cooling season.

[rileyrr]

Thanks Travis,

That is a very good point. I just looked more closely at at the Annual Operating Cost Estimate that Installer #1 provided which breaks down the differences between using the 16 SEER 38TDB and the 14 SEER 38TXA. Annually, the estimated savings is only $42 (for our area), so I have a call in to find out the difference in price between the 2 units. It looks like the 38TXA also comes in a 3.5 ton unit (instead of 4 ton for 38TDB) which more closely matches the cooling needs for our home.

There is a much larger savings between the furnaces (80% furnace versus 96%) estimated at just over $200 per year.

I also asked if the 38TXA can be matched with the 58MVP furnace and still utilize the Infinity controller.

Thanks again.

[dash]

Like I said ,buy the TDB for comfort,more even temps throughout the home,and better humidity control.

Infinity will work fine with the TXA ,just won't get diagnostic info from the outdoor unit.

[rileyrr]

Dash,

Could you explain what I will be missing by not getting diagnostic info from the outside unit if I go with the TXA? And how will humidity control differ between the TDB and TXA?

Thanks.

[ricknc]

We recently had an infinity system installed at our home in central NC. Initially, the setup was to be a 58MVP-60 paired with 38TDB-36. However, this was at a time when the local gas company rates were...let's say volatile. In any case, on a whim, I inquired about a heat pump. The contractor explained that with the infintiy control already spec'd as part of the install...the switch to 38YDB paired with 58MVP would be a nice dual fuel solution. The inifinity control handles this setup perfectly. I was unsure about a heat pump but liked the option...and the infinity control will let you configure it in just about any combination...ie only furnance...only heat pump....heat pump down to X temp...then switch to furnance....with this setup you in effect end up having 4 stages of heat and 2 for cool. Note...we also have the zoning system....really slick. At the time we had the install done...we had to wait a fair amount of time for the infinity zone control to arrive.

[docholiday]

I wouldnt ask for the exteded warrantee to be dropped, they are more often a bargain at any price. Usually one service call requiring a part will equal what you paid for that warrantee. In ten years, you will be making a repair at some point. (imagine your car on the road 14 hours a day for 10 years).

It sounds like #1 took the time to verify the ducts and load, and frankly there is never an excuse to oversize a furnace. I cant believe he suggests he doesnt like the unit going into high fire. That is simply absurd, ignorant justification. I might suggest that the installers dont build their price based on cost as much as you suggest, they charge what they are worth. Merely suggesting that the equipment is the same doesnt make a hill of beans difference when it comes down to performance and reliability. The sizing, and installation do that, and frankly attention to detail over guessing is worth something.

[rileyrr]

Docholiday:

Thanks for your insight. I am definitely planning on keeping the extended contract. As my wife put it, "You know it will fail in year 6 if you don't get the extended warranty to 10 years."

I just need to decide now if the ~$900 difference between the 38TXA (3.5 ton) and the 38TDB (4 ton) is worth it.

Thanks.

[travisfl]

Originally posted by rileyrr
I just need to decide now if the ~$900 difference between the 38TXA (3.5 ton) and the 38TDB (4 ton) is worth it.

The 38TXA is closer to the right size (as opposed to 20% oversized) and the simple payback on the more expensive unit would be 21 years.

[rileyrr]

Yes, I agree that the added cost will not be made up in efficiency savings. But, other than being slightly more efficient, I know the 38TDB has some other advantages over the 38TXA (as dash has alluded to). I just want to be clear on what I will not be getting with the 38TXA that I would have gotten with the 38TDB.

Thanks.

[travisfl]

Originally posted by rileyrr
I just want to be clear on what I will not be getting with the 38TXA that I would have gotten with the 38TDB.

The lower priced system is much simpler and has a scroll compressor, therefore it should be more reliable.

http://www.residential.carrier.com/r...ID3966,00.html

[dash]

The diagnostics for the two speed is really not an issue,IMHO.


The two speed will operate in low speed the majority of the time,do not be concerned that at full capcity it's oversized ,as the Infinity Controller will handle the speeds.

Operating in low,causes longer run cycles,at lower operating cost,longer run times will dehumidify better.It also helps to keep more even temperstures thru the home.


When you need it to "dehumidify" having low speed ,is a great advantage,to keep "overcooling" to a minimum while running just to dehumidify.


We have installed over two hundred Infinity Two speeds and cutomers love them,just look at "ricknc's" post on this thread.You might want to add Infinity Zoning,as he stated it's really slick and can add to the energy savings ,with set backs in certain zones,again it works best with a two speed/stage system.

Do a Search on this site,"Infinity" and see what other homeowners think of theirs.



$900.00 divide by 5475(15 years X365=54750=$0.164 ,per day.
WHAT"S Comfort worth to you??


[Edited by dash on 06-24-2005 at 11:07 AM]