"I asked the dealer for the COP but he said they don't use it any more..they now use SEER. Even Carrier support did not have this number" C.O.P. = Coefficient of Performance = btu's produced / electrical btu's in. This number varies with outdoor temperatures. It is not a single number like SEER. You need the Operating Technical Data for the heat pump to check COP as well as other info. COP determines operating cost of the heat pump in heating mode. "I am in Northern Virginia (24 miles from DC). My bills last year for gas was $926 (.099/kwh) and electric was $1,214 ($1.61/ccf)." Lok at the cost of one milion btus of heat for both fuels based on your utility rates: Heat pump w/electricity at 10 cents per kw-hr delivered price, COP = 3.25 at 35F ambient (1,000,000 / 3413 btu per kw-hr) x .10 / 3.25 = $9.77 Natural gas at $1.61 per therm, 80% efficient furnace (1,000,000 / 103,000 btu per therm) x 1.61 / .8 = $19.53 The heat pump costs 200% less to run than the 80% gas furnace (19.53 / 9.77). As ambient temps increase from the 35F example above, COP increases and the heat pump is even cheaper to run. Here are the COP numbers for my 3-ton 14 SEER Goodman heat pump based on ambient temps: Ambient temp----COP 65F-------------4.37 55F-------------4.04 45F-------------3.64 35F-------------3.25 25F-------------2.82 15F-------------2.46 5F--------------2.06 Below the balance point of the home (around 32F or so), the heat pump cannot keep up with the heat loss of the house because the btu output of the heat pump drops with temperature. Supplimentary heat is required below the balance point. My balance point is mid/upper 20's. Your climate is perfect for a heat pump. I'm in Baltimore - same climate. If you go dual fuel (heat pump plus gas furnace back-up), you have a choice if the price of one fuel drastically changes in the future. Choices are a good thing. A few notes about a heat pump (just so you know): - Heat pumps do not produce the hot 120F air temp of a furnace. They produce heat in the mid to upper 90's. - Heat pumps have a shorter operating life than straight a/c because they run in all 4 seasons. Best to you.

Do you currently have propane in the house or will this be new? Do you currently have sufficient capacity in your electrical panel for electric heat strips (200amps)? What TD is getting at is that apparent cost of electrical heat strips and propane is the same. Since a HP is more efficient than electric strips when it is operating (say above 28F), it would be cheaper to use a HP over 28f than propane (or electric strips). The decision depends on the cost difference of going with a HP over the discontinued AC the dealer is offering.

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

Reading this thread has reaffirmed my decision to upsize the Greenspeed per Carrier's recommendation based on my cooling load. I could have went either way: 3 or 4-ton with my heat load. Too bad they don't make a 3.5 ton, it would have been the perfect size. Last year's polar vortex in NY Long Island really pushed me into the 4-ton. The way I figure the unit will only go into defrost mode below 8-10F. I also have 300sqft of window space, three huge doors and a fireplace. No matter how much my thermal envelope is tightened there will still be leakage in this 75 year-old home. My biggest disappointment so far with the 4-ton is it only reduces its speed to 50% vs 40% for the 3 and 5-ton units. The information across the Internet is just plain wrong on that one. We're charting in brand new territory still, so hope I've added somewhat to the pool of information. Otherwise this unit is *way* better than my wildest expectations. The comfortability factor is way better than my single-stage and well worth the additional cost. I'd go even as far as to say perfect. We had a huge heat snap for two days 65% humidity and temps into the upper eighties still at 80F past midnight. I only used $3.15 for the entire day vs. almost $11 for a similar temp period last year. I also credit my new Sunrise windows with lots of the improvement. At full load the system was using approximately 1150W. It only went up to 70% usage for a very brief period at night. More importantly I could easily maintain rock solid 45% humidity at 73F. Not enough data to really extrapolate much else. The system is so quiet my neighbors asked why I hadnâÂÂt turned it on yet. :) The real test will be this winter though. I'll probably create a new thread to chronicle some of my observations. This post was edited by bsmith on Mon, Jun 2, 14 at 2:42