I am familiar with the area/climate, and I too believe that the equipment is oversized and will not perform optimally, especially the first floor system. Very common (and outright wrong) practice in the residential HVAC industry. I would not move forward without a load calculation. When you are given a written copy of a load calculation, post it here if you can. The 005 is the better matching fan coil size for the upstairs system. Same physical size as the 003, so space isn't an issue. I am also quite certain 15 kW of strip heat for the upstairs system is excessive as well. Sounds crazy for an upstairs heat pump system conditioning ~1200 sqft. I have 15 kW of back-up strip heat for my 4 ton heat pump system, which more than adequately conditions my entire house (~3000 sqft total) in MD. You've been quoted quality equipment at a fair price, I would only caution you to verify that the equipment is properly sized to your home's load. This results in the most efficient, reliable, and comfortable operation. Just as important as finding a qualified and competent company to do the work and provide exceptional service following the installation. This post was edited by ryanhughes on Sat, Sep 7, 13 at 19:32

Thank to you all for your help. We did not install the system last year but we want to do it now. Following other people's recommendation, we decide not to use heat-pump in Boston. Here are the quote from the same company with three different system. I'd appreciate if you could give me your suggestion which option I should choose. Are these price right in Boston area? Thanks Option #1 $6,515.00 Install (1)-Carrier, Base Series , 24ABC6, 16.00 SEER outdoor condenser with environmentally friendly Puron refrigerant Install (1)-Carrier, Performance Series, FV4, Variable Speed Air Handler Option #2 $7,255.00 Install (1)-Carrier, Performance Series, 24APA7, 16.50 SEER outdoor condenser with environmentally friendly Puron refrigerant Install (1)-Carrier, Performance Series, FV4, Variable Speed Air Handler Option #3 $7,485.00 Install (1)-Carrier, Performance Series, 24APA7, 16.50 SEER outdoor condenser with environmentally friendly Puron refrigerant Install (1)-Carrier, Infinity Series, FE4, ECM/Variable Speed Air Handler Here are more detailed tasks. Dismantle, remove and dispose of your existing basement central air system Reclaim and recover all existing R-22 refrigerant from your current system Disconnect and dispose of your existing outdoor condenser Install (1)-Carrier, Base Series , 24ABC6, 16.00 SEER outdoor condenser with environmentally friendly Puron refrigerant Install (1)-Carrier, Performance Series, FV4, Variable Speed Air Handler back into the same location as the current system is located Re-connect to your existing condensate drain, Modify the plenum to the new air handler from the existing duct system for a smooth transition Re-connect to your existing outdoor condenser refrigerant lines Reconnect to the existing power sources Install (1)-Carrier, Performance Series digital, programmable thermostat Your total for this install will be $6,515.00

Since you live in FL you may be quite right regarding the price increase of the Greenspeed since heating is not a priority. Greenspeed advantages may include quieter operation, less wear due to ability to operate at slower speeds, possibly even better humidity control and less costly to run. Whether this trumps the cost increase is certainly questionable. You could press for a fair price to consider the Greenspeed upgrade and the new Infinity WiFi thermostat as well if it's available. Don't forget the Carrier Fall rebates! That alone may provide a $230 advantage for the Greenspeed than for the 25HNB combo rebate. Don't forget to discuss the 10-year parts and labor warranties! SR

12" return is almost definitely too large for the basement. I have a 6" return in my basement, and I have actually found it to draw ~200-240 cfm (using a barometer) -- plenty in my case with just a few supply outlets. In your case, I have no way of knowing for sure, but I assume it's piped directly (or near) to the inlet of the furnace blower compartment, in which case there is a lot of pressure and it's sucking in a lot of air and making the basement quite negative (not a good thing). So your basement return in that state may have been drawing close to, if not more than, half of the return air the entire system requires. Is the basement floorplan open to the rest of the home or closed off? If typically closed off, I wouldn't be surprised if the basement door had a tendency to close itself when the system was operating. I suppose putting cardboard over half of the grille is one way to reduce its intake capacity. Your older furnace does not (presumably) have a variable speed blower that will vary its RPM in order to maintain a specific CFM setting. That means that while you are noticing more airflow from the rest of the returns throughout the home, in totality your system is receiving less airflow -- no, not a good thing considering your ductwork is likely undersized to begin with. You have decreased its return capacity. To get the SAME (total) airflow from the rest of the returns throughout the home that were not previously drawing as much air generally requires the system to operate at an increased static; with older PSC type blower motors (non variable-speed), this results in decreased airflow. Hence variable speed motors are often termed "constant CFM" as they can adjust (increase) their speed to maintain a constant airflow (cfm) when subjected to as much as 0.8-1.0" of external static pressure (vs. conventional blowers max. of 0.5", which many duct systems are nowhere close to achieving despite it being the standard "design" figure). You can think of the ESP number as a measure of resistance to airflow, in a sense. The fact that you say the (supply?) ductwork is now much warmer is both concerning and telling. It is unwise for me to say much more than that as I am not there to evaluate your system design and give an accurate assessment of the ductwork design/layout, etc. But it suffices to say, with the info you've provided us, your return ductwork is now more restrictive, which would exacerbate any existing airflow issues. You do say it met the set point without tripping the high limit. Please let us know how the system performs as it gets colder out and the system runs more often in its present state. I would like to ask what made you consider replacing the systems (and proceeding to get 8 proposals) in the first place? Are there functional problems with the existing equipment (besides most likely being oversized) or other comfort issues? By now we have at least established that it is likely the existing equipment is a bit oversized and the existing ductwork is marginal -- but that is (unfortunately) exceedingly common on most residential construction. Are you after more efficiency, better comfort, both? It helps us to help you when we know more about your current system's performance. Lastly, I would not factor online reviews into your decision too much. An air conditioner or furnace is not like most appliances (such as a refrigerator) in that the installation practices and quality can make or break even the best equipment selection. There is a good chance that many (but not all) of the negative reviews you read were due to installation errors. This post was edited by ryanhughes on Fri, Nov 22, 13 at 9:51