Original Furnace: Heil 9000, model # NULSO75BG04, propane
Original AC: American Standard Allegiance 10 - model # 7A0030A100A0

Here are a few details of our place:
- Located in central North Dakota
- 4408 finished sq ft (1032 top floor/loft, 1688 main floor, 1688 basement)
- Built in 1994 using Enercept SIPS (vaulted ceilings, no attic)
- PerfectAire Model 8100 Fresh Air Exchanger

- Propane: $1.62 average last year, $1.30 this year
- Electric: Facility charge of $14/mo - First 1000 kWh $.0777, Next 1000 kWh $.0690, $.0600 after that
- Average propane bill (10/11-10/12): $95/mo
- Average electric bill (10/11-10/12: $80/mo

I went to the Degree Days website and downloaded the following info. I ran the report for the last two years since this past winter was pretty mild and the previous one was more typical of a ND winter.

..................HDD.....CDD
10/1/2010.......557.....20
11/1/2010.......1126....0
12/1/2010.......1686....0
1/1/2011........1864....0
2/1/2011........1498....0
3/1/2011........1437....0
4/1/2011........758.....1
5/1/2011........399.....6
6/1/2011........118.....95
7/1/2011........16......270
8/1/2011........46......175
9/1/2011........276.....66
Total...........9781....633

10/1/2011.......519.....28
11/1/2011.......992.....0
12/1/2011.......1255....0
1/1/2012........1370....0
2/1/2012........1253....0
3/1/2012........748.....10
4/1/2012........562.....11
5/1/2012........272.....51
6/1/2012........79......171
7/1/2012........14......325
8/1/2012........104.....171
9/1/2012........288.....84
Total...........7456.....851

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Last Tuesday and Wednesday, I called five area companies (Coleman, Lennox, Ruud, Trane, York) and as of today, I have only heard back from the Trane and Lennox dealers (the Ruud dealer that I used to service my old system hasn't even called me back yet!). I received quotes from both and feel more comfortable with the Lennox dealer.

Below are the quotes exactly as they were written.

Option 1
Lennox SLP98UH090XV48C 98% Modulating Variable Speed Furnace with LP Kit
Lennox XP17-036-230 Single Stage Heat Pump
Lennox Cased A-Coil
Lennox Healthy Climate Air Filter and Cabinet
Lineset, Whip, Pad & Stand
PVC for Combustion Air Intake and Exhaust
Condensate Drain Material
Lennox icomfort Wi-Fi Thermostat
Supply and Return Air Plenums
Installed Price - $$$$$

Option 2
Lennox SLP98UH090XV48C 98% Modulating Variable Speed Furnace with LP Kit
Lennox XP16-036-230 Single Stage Heat Pump
Relay kit to make compatible with icomfort thermostat (price charged separately when released)
Everything else the same
Installed Price - About 5% higher than Option 1 (plus relay kit price when released)

Option 3
Lennox SLP98UH090XV48C 98% Modulating Variable Speed Furnace with LP Kit
Lennox XP21-036-230 Single Stage Heat Pump
Everything else the same
Installed Price - About 25% higher than Option 1

We plan to be in our house for the next 25-30 years so we'd like a very efficient, comfortable system. Based on the quotes, it seems like Option 1 or 2 would be the way to go.

Am I better off going with the single or two stage heat pump? Or doesn't it make much difference?

Any advice/suggestions/recommendations are gladly accepted.

Dave

You are allowed to post prices on this forum.

Upgrading to a 2-stage heat pump/AC is mostly for comfort. In the summer running the low stage will help reduct the humidity. It is a nice feature if you live in a humid climate. In winter the low stage will come on first so you don't get a blast of air when the furnace comes on. It will also run more quietly while keeping the house at the set temperature.