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What's better for you? Tough to say not knowing what you already have to figure in the associated cost to change from one to the other.
Scroll compressors are the new norm so thats an improvement over something 20 years old. Defrost controls haven't changed much. Whether you go with ac or a hp, the outdoor equipment will be much larger due to the increase in efficiency...it's all about surface area.
You can toy around with the linked spreadsheet for the annual energy cost figures.
In Atlanta borderline between the two.Heat pump is only good to 25 degree's,you may face a period of several days or below of this temp.
I'd assume they'd put in a new heat pump. No reason to put in an old one that has the 25 degree limitation. New ones are good down to single digits or lower.
Gas fired systems are far more efficient than heat pumps. Heat pumps are more efficient than standard electric systems.
Hope this helps.
Nope. New heat pumps are around 300% efficient, gas combustion is around 85% efficient. Might want to check on how efficiency ratings are calculated. In dollar terms, this means the per btu cost of electric has to be less than 3.5 times the gas rate for the total cost of using electric as a heating fuel to be lower. There other factors like seasonal efficiency to consider, but gas is never going to be more efficient than a heat pump even if you run it ventless.
Efficiency is just a number, the real question is the cost per BTU.
Quote:
Originally Posted by mkarch
Nope. New heat pumps are around 300% efficient, gas combustion is around 85% efficient. Might want to check on how efficiency ratings are calculated. In dollar terms, this means the per btu cost of electric has to be less than 3.5 times the gas rate for the total cost of using electric as a heating fuel to be lower. There other factors like seasonal efficiency to consider, but gas is never going to be more efficient than a heat pump even if you run it ventless.
Efficiency is just a number. A more useful number is average cost per BTU for the heating season, which is based on the seasonal performance factor (SPF), which is basically "real world efficiency" of the total heating system, including "supplemental" heat.
The colder it gets outside, the less the multiplier on an air-source heat pump, and the fewer BTUs per hour it can move into the house. Even when the temperature is warm enough that the heat pump still produces some heat, it might not be able to produce heat fast enough to keep you comfortable.
Another issue is overnight setback -- if you are accustomed to turning down the thermostat at night or when you are out, you will find that the heat pump takes much, much longer to bring the house back up to temperature than your old gas-fired hot air furnace did.
The workaround is supplemental heat, usually resistive electric heat. Sure, this is 100% efficient, but also really expensive to operate, reducing the SPF closer to 1.0 and increasing your heating costs.
<sigh> Heat pump with gas auxiliary heat. Best of both worlds and no religious wars.
I'd really question when the break even point would be on a gas backup to a heat pump system would be in Atlanta. Decades? The average January low is 28 degrees, well above the point where gas backup would pay for itself.
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Efficiency is just a number, the real question is the cost per BTU.
