replacement of lennox gas furnace

[deltaphi30]

please help-any advice on the differences/quality of the 3 brands i have offers on:
1. AMANA/AMS9/ACS9 single stage 60.000btu 93% AFUE
2. LENNOX GSIMP36B70-70,000 btu 92% AFUE
3. RHEEM-RGRA09 90,000 BTU 93% AFUE

We are replacing a 90,000 btu lennox about 17 years old. My home is about 1200 sf to heat (3rd story) no ductwork.

I'm really lost trying to determine which brand best fits our needs. We replaced all windows in the house in past 5 years.

One installer said perhaps 2-stage furnace another said absolutely not needed. I live in Western PA where winters can get cold.

Any help please is much appreciated.

[BaldLoonie]

90K 90% seems WAY OUT OF LINE for 1200 sq ft. Sounds like this maroon just based sizing on what was there. Question them all on how they arrived at size but with a small space and new windows, the Amana is the only one that sounds close to proper sizing.

[t527ed]

lennox -70 size furnaces actual input 66,000 btu. model you have is wrong, is it a 51 or 61 model? 51 1 stage, 61 2 stage.

[HeyBob]

I would go with the G61MP, it's 2 stage, 66,000 btuh. They have been absolutely trouble free for me.

I don't even stock G51's anymore, heck I have a 2 year old G50 I can't get rid of. Everyone wants 2 stage.

[Irascible]

You're focusing on the wrong thing delta. Learn what things constitute a good furnace installation. Then find a contractor that does those things. As you can already tell from the replies it's obvious that some of your contractors haven't put much effort into properly sizing the furnace. That's only the beginning of your potential problems. You'd be amazed at the number and variety of ways a contractor can botch an install.

You are buying a service first and a product second. Find those that deliver the best service and buy whatever brand they install. You'll end up regretting it if you don't.

[deltaphi30]

OK I get it-focus on the service (I run a service center and I know that) however none of the three contractors said much while here doing the estimates.

In writing I have Lennox G51MP36B70 (70,000 BTU) 92%efficiency-single stage-complete with necessary duct adaptations, power and control wiring, controls & digital thermostat. Include new cold air return in DR. Dispose of old equipment

2. Amana-AMS97 66,000 BTU/labor, performance control center, talking programmable control center, permits, removal/disposal of old equipment, check entire system for safety/efficiency, check for minor leaks in exposed ducts, new flue, filter for furnace electric filter.

The Lennox dealer we have done business with for years-they are on the high side and having financial troubles I've heard.

The other is part of a group I've never heard of the "Ainsley 500" HVAC.

How do I obtain more info to make my decision. The Amana dealer did a measurement of the sq footage of the house and talked about some of your suggestions-heat flow, but nothing about the duct flow.

Just replace into existing ductwork-and I have no idea if this is adequate or we need an update.

No one came equipped with a computer or program to do any type of measurements (except the Amana) and that was with a ruler.

My home is old (over 60 years, frame) and we've updated windows recently (5 yrs.), has blown in insulation from over 25 years ago.

It appears to me everyone is content to take the out furnace out and put the new one in-what else can I expect or discuss with the contractor to make sure I have the right answers with this major investment?

In a small community-it is hard to be sure you are getting both quality and service with limited resources available.
Thank you for your help.