Heating, Air Conditioning, Fridge, HVAC/Heat Pump vs. Dual Fuel System


I need to replace my old furnace.  I have a home in the Carolina Mountains at approx. 3400 feet above sea level.  It is half a duplex. The other side is occupied. The home is 1296 sq ft under air with two 8 foot sliding glass doors facing to the north with large windows above that, so when cold fronts come in, they take a hit.  These doors are heavy and double paned, but drafts still come through.  I have had 4 estimates done and confirmed that due to northern exposure and high ceilings, I need a 3 ton unit. Many in the area have gone to straight heat pumps with strips, but where my place is, it is a little cooler.  The companies are providing me estimates for both dual air and straight heat pumps (14 seer).

The summers are nice, needing only occasional cooling over a couple of months a year.  The winters are mixed.  Our temps are on average about 2 to 3 degrees cooler than neighboring Asheville. NC.  The normal cold months are December through February averaging low to mid 20's as lows and mid 40's as highs.  There will be cold days and I have seen it as low as 5 below, but that is very unusual and may happen twice a winter.

The issue I have is, should I go with a straight heat pump with strips or should I go with dual fuel (I have propane already in place for a dual system and it will be used for my the fireplace and clothes drier, regardless of what I do).

I know the dual system will cost more on the front end.  

I've done the research on how the two different systems work and what the pros and cons might be.  I'm looking for an experts opinion that has practical real life experience and no dog in this hunt.

Here are my questions:  

Given the scenario above, which system will provide the best efficiency and cost savings in the long run?  Which would be more reliable?  How about the HSPF?  What range would be best?

I have estimates with Trane, Rheem and Coleman equipment.  In your opinion, is there a big difference?  Definitely some price differences there.  I have been told, even by the Trane rep, that the most important issue is the installation and that it be done properly.  

Your opinion is greatly appreciated.  Please let me know if you need more info.

Thanks much.


Hi Jerrod, IMO a heat pump with electric back up would be your best bet. To me 3 ton's on a 1300 sq ft house seems to large. Has anyone done a load calculation ( Manual J)?

On the HSPF, the minimum is 7.7 and goes up to 10. The higher the better. The three unit's you mentioned are all good units. I wouldn't have a problem putting one in my house. Trane and Rheem are probably the most expensive and Coleman a little less expensive. I agree with the Trane rep. Go with the one you feel most comfortable with. Let me know if you have more question.

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Jim S.


I can answer questions on gas or electric furnaces, ac units and heat pumps. I don't work on boilers,chillers,or home appliances.


I have been in the HVAC trade for over 35 years. For the past 15 years I have owned my own business. I am semi-retired so I can answer questions in a timely manner.

I attended trade school for 5 years on weekends and evenings. This was very hard to do, but well worth it!

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