Plymouth, IN: the heat pump payback math
In Plymouth, a heat pump would cost more to run each year than what you have now. Against a like-for-like gas furnace and AC swap, going electric costs $3,500 more up front here (already netting out a $2,000 tax credit). The heat pump would cost about $170 more a year to run than the furnace it replaces — a premium with no payback. There's no spin on that: Plymouth's numbers say wait.
Why Plymouth's climate drives this number
Degree days tell the story here: Plymouth racks up 5260 heating degree days each year (base 65°F), and summers add a moderate cooling load, with 580 cooling degree days on the cooling side. Sizing runs off the design temperature, not the average day: -0.4°F here (record low -7.6°F), which works out to a seasonal COP of 2.69 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Plymouth — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Source: NOAA station STARKE COUNTY AIRPORT, 18.1 miles from Plymouth — the closest one on record.
The month-to-month numbers for Plymouth
Electricity use for heating alone comes out to about 4,951 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $927 a year. The gas furnace it replaces burns roughly 55 Mcf a year at 11.49 per Mcf here, for a running cost near $757 a year (electricity here runs 17.03¢/kWh). Looked at as a full purchase rather than an incremental one, payback here is longer than the 15-year equipment life, leaving the 15-year total $6,050 behind.
If your home heats with electric baseboard instead of gas
Plenty of homes in Plymouth heat with electricity alone, no gas line involved. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. About $1,469 a year comes back this way, enough that the 5.4-year payback clears the $8,000 premium comfortably within the equipment's life.
How Plymouth compares nationally
Ranked against the other 3206 cities covered, Plymouth comes in at 536 for heating severity — 1 would be the coldest place in the dataset — and 2982 by population, where 1 is largest. That's the coldest third of the dataset, where climate does most of the work behind this figure.
Next step for 11,042 people in Plymouth
About 11,042 people live in Plymouth, Indiana, and every number on this page is what a contractor would actually work from when quoting a system here — the point isn't to replace that quote, it's to tell you whether to bother asking for one. Here, there's no cost penalty to waiting until your current furnace or AC actually needs replacing.
Get quotes from local HVAC contractors before deciding.
Reading further on this page's numbers
Nothing above is a black box: the methodology guide shows the full arithmetic behind Plymouth's 2.69 seasonal COP and payback figure. Plymouth's -0.4°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.