Hi All. Live in eastern Ontario and just got installed a Greenspeed 25VNA048 heat pump w a 59MN7080 gas furnace to stop paying for oil. It was a learning curve for this system as it is an advanced heat pump system - expect the competition to ramp up their pumps HSPF to 13 also or lose the market. My coldest night so far was -15C and we got our 21C/70F indoor temp in our 2800 sq.ft house.My balance point is set for -17C/1F and I should be getting to -18C this wed/Thurs evening for a real test for the normal switch to gas furnace. Yes the system by default uses gas heat on defrost. Without it it would be blasting cold air in the ducts for 5 minutes. So the gas frnace heat modulates at 65% so to neutralize the cold air so air temp swings are minimum for comfort. Yes you can disable this on the touch screen interface in service/ setup/ heat source lockouts. Yes one can monitor electrical costs in $$$ or Kw and gas $$$ or therms on a per day/ per month and per year to date on the interface. I've experimented between the different options in choosing efficiency or comfort and there is a noticeable difference to the environment and a slight increase in costs of electricity between the two. I do prefer comfort. On an average cold day 0C/32F w -5C at night it costs me @ $5 per day in electricity and with heat on defrost w/ continuous low fan for only an additional cost of $1 every third day (.33cents per day). (yes the different areas of kw usage is separated in the readout) The only puzzle I have to resolve is last Saturday nite at 3 am the house felt cold - it was 15 F outside. Gas furnace came on for a couple of hours before pump came back ???. No codes or resetable fault codes registered on interface. The only way for the gas to go on at that temp way above the balance point is a 2 degree drop or a manual increase of temp of 2 degrees or more. So why did did happen.... stay tuned.... Gotta love saving money. Last year in October it cost me $425 in oil - this year for Oct gas+electrical $202 Included is a pic Update Jan 2014: had issues w furnace overiding heatpump prematurely and Carrier change my thermostat which had Version 9 to version 10 software - issue fixed. those who want to see what savings a heat pump can have over your specific system try this: http://sagoro.wrightsoft.com/Carrier/Default.aspx This post was edited by Cocobob on Mon, Jan 13, 14 at 23:22

You should definitely be pricing with just heat pump. I live in NC which probably is a bit colder in the winter. We get down to the teens but only 15 nights a year maybe. Our winter average low is about 30. Under 10 degrees is definitely a news story. I have 5000 sq ft. I'm looking at my NG bill of $30. I have dual fuel and seer 16 heat pumps. Last winter was very cold and I spent about $700 with $200 being gas. This winter is going to be $120 in gas. My electric rates are similar to yours without the first 1000 discount. What is my point? Your gas usage will likely be $100 a year. Even if that were replaced with all heating strips, you'd be saving $200 a year or so. Since it would probable be 80% heat pump still, the dual fuel is only saving you $40 a year. So a $2500 furnace to save $40 a year seems a little crazy (on dollars alone). Turns out for me, it is probably worth it but only marginally so. I have a 90% (which you should be able to do as mine is basement with horizontal PVC exhaust). It probably saves $60-$70 on an average year. Probably cost $2000 (new house - I can't remember). What is that a 30 year payback (or never if you count interest or NG rates increase)? You do get some flexibility and you can setback at will with dual fuel. That is worth something.

You will probably need to call Carrier tech support and see how they want you to do it but I am pretty sure the scenario you are suggesting will not work notice they are asking to use an open on humidity increase open and close switch and this switch is just taking the normal cooling setting G terminal out of the control loop at your determined high humidity set point so as to decrease fan speed and result in longer run time for your cooling cycle I don't believe that is what the dehumid 2 function does on the IAQ of course I don't have the installation manual in front of me so I may be wrong but just remember that you are not looking for a 24 volt signal the G terminal will already have that at the call for cooling they just looking for a high humidity setting to open that signal to the G terminal and allow the furnace to go into lower fan speeds Here is a link that might be useful: Air Conditioning Repair made Easy

Never a bad idea to replace the copper lineset, but oftentimes it is very difficult if not impossible (think about condo complexes where the lineset often runs between walls of other condo units). If reused properly (i.e., blown out with nitrogen with a deep vacuum) and the proper size, they don't always have to be. The leak is most likely not within the lineset because it is one solid piece throughout. 2 stage units provide an advantage in terms of humidity control; however the 16i and Carrier models (and any brand using an unloading Copeland scroll compressor) run at around 80% capacity on low, so there isn't a huge turndown for the price premium. While I prefer Trane equipment over Carrier myself, both manufacturers make excellent equipment with comparable warranties, and both should do a fine job if installed properly. I think in this case, if looking at 2-stage units, the Carrier system with the Infinity control is the better system simply because the Infinity control does a much better job controlling the system than does a standard 2-stage thermostat such as the 802. Looks like the Carrier dealer finds that your home needs a 3.5 ton system (or 4 ton if 2-stage) while the Trane dealer is quoting slightly larger equipment. Something to bring up to the Carrier dealer. However if 3.5 tons is indeed the proper size, and a 4 ton is installed -- while it would not be a major issue in terms of comfort or efficiency -- the 3.5 ton would certainly be better in terms of humidity control and efficiency because it would not be short cycling as much on milder days. The single stage Comfort 15 with v/s air handler and the TP-PRH control will also do a good job with dehumidification without the added cost of 2-stage, but with the rebates and the Infinity control I think the Performance 16 is the better choice if going the Carrier route. I realize I haven't exactly convinced you to go with either system, but know that either one should do a fine job if sized and installed properly. The installer is key. All in all, I think you'll get the most out of the Infinity system.