How long do you plan on being in this home?

You don't say the size of the furnace 1st Lennox quote.

The first Carrier quote with a 120 KBTU furnace is grossly oversized.

Toss quote 4 and 5 in the trash.

I will come back to the Trane quote in another post.

I would not purchase a new system that did not qualify for Fed Tax Credit.

Post back.

IMO

Yeah, it doesn't show the size of the furnace anywhere in the 1st quote, all I can find is "SL280V 090V60C 2-stage 80%" everything has been 80k or 100k BTU so maybe one of those? I'll call the guy tomorrow and see if he can tell me.

I'm really not sure about the house, probably a good 10 years or so at this point.

Some of these quotes have a Fed Tax Credit and some have "and/or" Manufacturer Rebate. The first Lennox quote says $400 from Lennox + $400 from the power company. So $6,780-$800= $5,980 in the end.

The guy that gave me the 2nd quote had a few other options, one was for a $10,000+ Carrier system but the other two quotes were:

$6,912
Carrier PG92SAS60120D 92% 1 STG 120K BTU
Payne PH13NB048000 4 Ton Condenser AC
Carrier CNPVT4821ALA 4 Ton Evap Coil

$8,217
Carrier 24ACB348A003 4 Ton single stage AC
Carrier 59SC5A120S24-20 120K BTU
Carrier CNPVT4821ALA 4 Ton Evap Coil

I don't know why 120K BTU when everyone else was 80K but surely there's similar models that are smaller along that same line.

All of these prices are assuming I'm paying full upfront, some quotes give 5% off if you pay in full, others took $500 off the equipment, etc. so I'm showing the lowest possible quote.

Also, regarding quote 5, I just noticed that they added $500 to add a vent to part of the unfinished basement. I won't do that so the quote should be:

5. Carrier - $5,500
58STA090-16 - 90,000 BTU 80% single stage
24ABB348A003 AC 4 Ton 13 SEER
Evaporator Coil - CNPVP4821ALA 4 TON 13 SEER
AprilAire 2410 media air cleaner
Honeywell PRO SERIES 6000 with WiFi

How long do you plan on being in this home?

What size and efficiency is existing furnace and AC that you intend to replace?

I like the Trane system best. What evap coil Mdl number?

I would upgrade to the XV95 furnace, 80 K size. The savings would pay for the upgrade in probably 4-5 yrs.

IMO

I agree -- I like the Trane estimate as well. You do need to ask for the evaporator (indoor) coil model number.

With the first Lennox quote, while Pro 8000's are great thermostats, they cannot control the heat stages of a back-up fuel source in a dual fuel application. What that means is that when it's cold and the furnace assumes operation, it will go to high stage based upon time versus demand. Not the best way to control the 2-stage furnace you paid a premium for, and many of the comfort advantages are diminished with this control scheme. Unfortunately not too uncommon to see 2-stage furnaces set up and installed this way. The VisionPRO IAQ (model YTH9421) would be what you want. Both touchscreen/programmable. The IAQ can control humidity in both summer and winter when set up to do so.

If you do pursue the Carrier estimates further I would stick to the 24ACC or 24ACB series condensers at least. The 24ABB models don't have high/low pressure switches to protect compressor or good outdoor coil protection.

This post was edited by ryanhughes on Wed, Aug 21, 13 at 8:43

Mike

Just to be clear, the Trane quote is not a DF system, so a heat pump is not involved.

I agree about the thermostat selection.

For Jacko, I want a system that qualifies for Fed Tax Credit with the XV95. See below.

5996430 Active Systems XR17 TRANE 4TTR7048A1 4TXCD063BC3 1365 1090 *UH2B080A9V4 48500 13.00 17.00 1 RCU-A-CB 345 Yes

Ask about that coil selection for your application. And I would prefer Trane's Perfect Fit Media cabinet. Ask dealer if he would swap the AprilAire for the Prefect Fit Trane model.

IMO

"I just purchased a 2,400 sq ft home in Atlanta that has a 30+ year old General Electric HVAC system."

If A/C was new when house was built; home was built in1983.

Is it well insulated & tight; is the duct system properly sized for a 4-Ton/1600-CFM & well sealed?

It seems to me that in Atlanta GA with a 2.5% summer design; 92ðF & 74ðF wet bulb for 43% RH; you should be able to make a 3.5-Ton work, & then you could get the airflow CFM as low as 1225-CFM ( 350-CFM per-ton X 3.5-Ton)

Then if you size the return-air filter-area at 325-sq.ins per-ton or 1138-sq.ins, (/2 is 569 each or "two" 24x24 filters) that will get the velocity through the filter(s) at less than 300-fpm as required by manual D for throw-away media filters.

These are necessary requirements if you really want efficiency.

Try reading all the simple instructions & do a number of load-calcs.

Let us know all the results, so we can see if you used the calculator to figure the infiltration CFM, etc.

Here is a link that might be useful: Totally Free Online Whole House Load-Calc

Hi all,

Sorry for the delay, I've been traveling for work. As to the follow-up responses.

I'm still waiting on a response to the Trane coil model #

The house was built in 1981 but after further investigating the furnace, it has a 1978 stamp on it. It looks like its a 135,000 BTU unit which seems way too big unless the standards were just that drastically different back then. It's a General Electric Furnace BLU135E948B1. The ductwork around it looks shady and a few of the guys that gave me quotes said it's likely only 30-40% efficient.

I'll try a few load-calcs and post back, I don't know the status of the insulation, the attic doesn't seem too bad but I'm not sure what's between the walls. It's technically a ranch style home but there's a huge basement and the furnace, etc are in a finished crawl space which is 50% of the "downstairs" part of the house. I call it a 2 story ranch because it has as a bedroom, bathroom and a den downstairs as well. The basement area has carpet and walls but no ductwork was done so it's technically unfinished in that sense. I think some of the quotes were assuming the entire bottom floor was vented.

Im a believer in doing load calculation (even paying someone to do a ManualJ) and properly sizing the a/c for the house. Also proper ducting that is sealed well will go a long ways.

Jack

If you have a finished basement area with no ductwork for conditioned air, this should be looked at by dealer for suggestions to improve.

Also existing ductwork system should have a top to bottom review as to size, design, both supply and return, insulation properties, overall condition, and definitely a leak test.

Putting money into an an expensive new HVAC system is great but defeats the purpose if ductwork system is in poor condition.

IMO