Based on the energy costs you provided, the approximate cost per kW of heat delivered into your home with the Greenspeed gas furnace at full theoretical efficiency of 98.5% would be about 4.3-cents/kW, with a Greenspeed HP (COP-3.3, HSPF 11.3) and all electric fan coil it would be about 5.78-cents/kW if you lived in region 5 and about 5-cents/kW if you lived in region 4 (HSPF 13). This has to be balanced against the cost differential of the 2-systems including the cost of the gas line installation and chimney/liner installation (particularly if you wouldnâÂÂt be using gas for anything else) minus any promotions by Carrier and the various utilities or governments. You might want to consider which type of system may have the longer life cycle and lower maintenance costs. Regarding the HRV, you might want to ask the contractor if the Infinity T-stat will control the Venmar WITHOUT the Carrier NIM (Network Interface Module). If it wonâÂÂt, there goes your $230 savings! SR

Thanks for the comments tigerdunes. We've been over this quite a bit already. The pricing is average for the North East....labor rates tend to be quite high and the $600 rebate makes the price of the furnaces excellent. I obviously have two stage thermostats and the sizes of the furnaces were decided after heat loss calculations. I live in an older home in a cold climate and my calculations were within 10% of my contractor's. The calculation for my two floor unit came in at 75kBTUs. The contractor initially wanted to install a 100kBTU unit, but I talked him down to 80kBTU. The furnace for the renters below me is a bit large, but it was the smallest two stage available from American Standard. I thought about installing a 92% efficient 40kBTU single stage furnace with selectable motor speed, but as the 60kBTU two stage with variable speed motor was the same price after the rebate I went with that one.so that both furnaces essentially the same and to get the variable speed blower. I imagine having the second stage will also be nice on very cold mornings.

Mike_Home - Thank you for the answers and advice. Here are some responses and follow-up questions. 1. SEER/EER - your answer is what I had been slowly understanding that these numbers are what drive the efficiency numbers. Rough calculations comparing my older 10 SEER unit to a 14 and 16 SEER unit plus using 1 year of energy bills, show a potential electricity improvement of $184/year for the 14 and $238.31 for the 16. Of course this is all dependent on a quality install as well as proper ducts, etc. as you've outlined in other points. 2. Payback will be uncertain as I was relocated for work. Not sure how long we'll be here and at this point, the energy savings per year is still important. 3. Understood. Before my research, I didn't realize that the furnace played such an important role in airflow. 4. My zoning explanation might have been poorly stated. The gist of what was mentioned, was that based on proper zoning, the more efficient airflow distribution within the home may allow for a 4 ton condenser. The condenser potentially wouldn't have to push air through all of the ducts at the same rate. Does that logic track with your experience? 5. Appreciate thermostat advice and handling all the features, etc. 6. The annual maintenance contract was from the contractor providing the detailed Goodman quotes. Participating in the yearly maintenance contract covers 100% of repair costs (Contractor backed, not OEM), includes a 10 year replacement warranty, and there are no dispatch or service fees for service calls. The replacement warranty is the full replacement of the failed unit rather than just repairing under the 10 year labor warranty with Goodman. If I don't do the yearly maintenance contract, there is no replacement warranty. Ever heard of this? The contractor (Goodman quotes) may have mentioned "calculations" at one point but I don't remember hearing about them doing a manual "J" load calc. As far as I can tell, Title 24 doesn't require the J calc. It does require a duct leak test performed by a certified 3rd party HERS testing company. This is required on ALL HVAC projects in CA. Rebates are only available as part of CA's Home Upgrade Program. This program has required testing and upgrades on items like ducts, whole home envelope, attic insulation, etc. I will go back to two of the contractors and ask them about performing the calculation. I am looking to replace the whole system at this point to make sure the equipment is compatible and most efficient. Goodman is making me increasingly nervous, especially with the Class Action lawsuit that was just set back last week based on a judge's ruling... As for the use of a different coil with the Goodman equipment, it seems to be very common with Goodman quotes (based on board postings like this). I think there is a relationship or commercial connection between Goodman and Aspen to drive the high use with Goodman systems. I don't know the true specs on the Ruud equipment, I was guessing a bit; I will ask for the models, etc. Thanks again!

My question is, shouldn't the contractor have known the vent was too small when installing the unit? Yep and he should have known that 3 ton was too large also. Proper design is 400 CFM per ton and proper design for return is 2 CFM per sq in. So you would need return/supply design of 1200 CFM (which is too much for that sq ft), and a return grill total of 800 sq in (aka 20 x 40) I wouldn't want him to come back and do anything further, get someone else. Glad you got it covered, if parts are under warranty it is through the MFG not through the HVAC company. Perhaps a battery backup between the power source and the furnace is an option if somehow power outages are causing it. Maybe you are getting surges (or the blower motor is causing surges) and the battery backup would filter out the surges as well.