Time for a new furnace

[quarbis]

I have two bids for a new gas furnace and central air conditioner. One is for a Trane XL80 2 stage 2 speed 80,000 BTU furnace with a Trane XB13 2 ton A/C and a Honeywell Vision Pro Digital Thermostat. This system has "lemon guarantees" - if the heat exchanger fails during the furnace's lifetime, the entire furnace will be replaced free and if the compressor on the air conditioner fails within 10 years of installation, the A/C will be replaced free. Plus 5 years on the condensor coil, evaporator coil and furnace parts.

The other bid is for a Bryant Plus 80t Model 312 2 stage 70,000 BTU gas furnace with a Bryant Quantum Plus Model 591B Puron A/C with a digital setback programmable thermostat. This system comes with a 20 year guarantee on the heat exchanger, 5 year parts and 5 year compressor guarantees. The salesman did say this system is very quiet. (quieter than the Trane???)

We live in Indianapolis so we have hot summers and cold winters. Our house is small - only about 950 square feet.

Can someone with some knowledge of these things make some sense of this for me? Which one would be a better system? The Trane system is more expensive than the Bryant system but with it's warranties, it could be worth it. Any help will be appreciated.

[Jultzya]

Beings you live in Indiana, I would opt for a higher (90+) efficient furnace or a heat pump system.

First thing you need to have is a load calculation done on your home. The two systems you have received quotes on seem VERY large for a 950 sq ft home!

As far as systems go, the system is only as good as the installer. So find the BEST installer you can possibly find!

[spiderkiller]

I live in Indiana, and i know the weather, my home is aprox 1150 sq. on ground floor with full basement , i installed a 90% 60K btu with a 2 ton ac and it works fine ,a heat pump is efficiant untill outside temps go below 30-35,you may be ok in your area.

[dan sw fl]

Originally posted by quarbis
We live in Indianapolis so we have hot summers and cold winters. Our house is small - only about 950 square feet.

Can someone with some knowledge of these things make some sense of this for me? Which one would be a better system? The Trane system is more expensive than the Bryant system but with it's warranties, it could be worth it. Any help will be appreciated.

Electric Rate $0.___ / kW (10 cents ?)

1 therm [U.S.] = 29.30011 kilowatt hour
1 kilowatt hour = 3,412.1415 BTU
1 therm [U.S.] = 100,000. BTU

Gas Rate $____/MCF ( Therm ) ($11 / MCF ?)

Heat Pump will provide C.O.P. of nearly
three down to 20'F and
may suprise you with the economics in today's market.

C.O.P.
http://hyperphysics.phy-astr.gsu.edu.../heatpump.html

.......
House dimensions
... something like 44' x 22'

Window Area
North __ S.F.
South __ S.F.
East __ S.F.
West __ S.F.

Heat loss maybe < 29,000 BTUH
IF you have good insulation (R-11 wall - R-30 ceiling)
and double pane windows.

I may recommend 4TWX6024B1 / 4TEE3F031 with 8 kW strip
depending on Your electric rate$.



[Edited by dan sw fl on 10-28-2005 at 06:16 AM]

[BaldLoonie]

I have a 950 sq ft house in Indy. 2 ton will keep it 68 on the hottest day, I have my 2 stage furnace locked on low at 48,000 BTU input and that does fine well below zero. You definitely want a heat pump. With out obscenely low electric rates, dual fuel is the ONLY way to go. I did it next door for friends, they saved a bundle last winter. I had it for 10 years. You sure don't need a 13 SEER A/C. You'll save $20 a year and pay hundreds for it. From what I hear, 10 SEER Tranes are hard to get, that's probably why they are pushing it on you.

Back to the Trane, find out who is standing behind those warranties. Trane isn't.

My e-mail address is on my web site in my profile if you want to get more info from me before doing something.

[wyounger]

That Trane furnace sounds way too big for this application.

Note that while Bryant/Carrier puts 070 in their model numbers for 80% furnaces, those furnaces are actually 66,000 input.

[Irascible]

Originally posted by jultzya
As far as systems go, the system is only as good as the installer. So find the BEST installer you can possibly find!

The equipment and warranty debate would only be valuable if both contractors were top notch. The odds of that being the case are pretty low. I realize lots of contractors put on a good show. But when you dig deeper you find very few that do things right from top to bottom. A heat load calculation, Manual D calculation, proper diffuser selection, proper lineset size selection, the use of micron gauges, air balancing (the list goes on) are all things that even the slickest looking company will skip or gloss over simply because you don't know any better. Find one contractor that really does the job right and you'll have your answer. Why? Because you're not likely to find two.