First of all, you don't give the sizing of furnace and AC condensers quoted.. Repost. As to Lennox, it is a distant third in the top tier HVAC brands. One and two being Carrier and Trane and their sister companies Bryant and Am Std. And yes, they think highly of their product. I don't know enough about Maytag other than to say they are part of the appliance brand HVAC companies marketed by parent Nordyne. For the most part the HVAC is identical across the various companies. As to Amana, it is cosidered to be the premium brand to parent Goodman. You should note this dealer is quoting a Distinctions furnace which is a rebadged Goodman. I don't care for that furnace. I would want a true Amana furnace. What efficiency are you looking for? Lennox dealer quoted a two stage var speed 80% model. You might look at one of these Amana furnace models. 80% AFUE AMVC8 / ADVC8, 80% AFUE AMEH8 What size HVAC are you replacing? Post back. IMO

I did my own analysis using daily temperatures for the past few years to determine the required daily BTU for a given day. In general, it would be extremely rare for the gas furnace to turn on if I gave priority to the heat pump (~$20 to run the gas furnace for the least efficient option). If I factor in initial equipment cost, the Carrier Greenspeed becomes the least expensive option by the end of year 3. Does anyone have any comments r.e. pricing and/or quality? Thanks!

Hi, Thanks very much for your responses. - Everyone I've spoken with, and you've confirmed, that one zone per floor makes sense. If I'm missing anything else about "zones", please let me know! - How much should it cost to go from 2 zones to 4? - We are definitely going to put in all new ductwork. Is there anything here that I should be aware about or ask for? Any sites (besides GW) to get more knowledge on this area so I can ensure we get the ducts sized properly? - Good comments on getting more info on the geo wells, piping, etc. Will do. - Can I get a Manual J done even if the house is under construction? Framing is almost done, but the exterior work is not complete, and so it's open to the elements right now. - Yes, we have a natural gas furnace and electric AC in the house. It appears that a NG furnace was installed in 2007. The unit is a Lennox Signature Collection, model CX34-62D-6F. We also have an electric hot water heater, AO Smith ProMax Plus, model FCG 75 300. Does it make sense to re-use these or upgrade? Obviously, the furnace will be out if we go with geo. - Here's a summary of our NG and electricity rates. I hope I'm doing this correctly -- taking the bill amount and dividing by the energy used. Some months may need to be taken out because the numbers are too high/low. Please note that we have not lived in the house, so this is what we were paying for several months before construction commenced. So I would expect actual usage, and thus our bills, to be higher, but I guess that the cost per unit would be somewhat proportional. Natural Gas Monthly Charge / Therms Used / All-In Cost Per Therm $18.06 / 5.1 / $3.54 $16.76 / 5.1 / $3.29 $51.90 / 32.5 / $1.60 $78.53 / 57.7 / $1.36 $339.62 / 314.7 / $1.08 $362.71 / 321.1 / $1.13 $184.41 / 154.8 / $1.19 $81.98 / 60.4 / $1.36 $66.62 / 47.4 / $1.41 $18.45 / 7.1 / $2.60 $16.18 / 5.1 / $3.17 $1.97 average Electricity Monthly Charge / KWH Used / All-In Cost Per KWH $285.18 / 1757 / $0.16 $137.36 / 786 / $0.17 $77.44 / 416 / $0.19 $57.91 / 316 / $0.18 $66.29 / 382 / $0.17 $86.87 / 524 / $0.17 $61.02 / 341 / $0.18 $24.50 / 76 / $0.32 $25.22 / 80 / $0.32 $38.34 / 73 / $0.53 $21.23 / 53 / $0.40 $32.62 / 140 / $0.23 $0.25 average - It must not be code on my state (MD) to have each floor zoned. Our bids have been for two zones (on per system, one system covering basement and first floor, second system covering second and third floors), or for four zones (running off two systems). - Thanks for the heads up on the tax credits. My husband is tracking these, so I'll make sure he knows this. - The addition is on a loggia, not crawl space. So the basement is a walk-out basement, and the loggia will in effect extend the basement, and then the kitchen/family room addition will be above this, and our master bedroom addition above that. It's at the back of the house. Here's an early photo so you get the idea. The house is brick, and the addition will be part brick, part clapboard. - I am trying to learn what an HRV is, so am looking into this. - If it's not a good idea to go with spray foam insulation, let me know! Thanks for the info on what type would be good. - More thoughts on what system to go with, pricing, etc.?? THANKS AGAIN!!

WHAT IS A HIGH LIMIT SWITCH? https://www.newcentralairconditioner.com/ The high limit switch in your gas furnace is a small part with two very important jobs. This switch plays a role in the normal operation of your furnace. Turning the fan motor on and off is the high limit switch’s main job. This is the role it plays in every cycle of your furnace’s normal operation. But that’s not the only thing that the high limit switch does. It’s also safety device that helps prevent your furnace from overheating. The high limit switch consists of a long temperature-sensing probe attached to a metal mounting plate. From the mounting plate, the switch is wired to the blower fan motor and to the gas valve. The switch is generally located just past the heat exchanger. This is so that it can detect the temperature of the supply air. In other words, the air that’s about to be blown into your home.