New gas furnace + new AC
Lowest 15-year cost
- Installed
- $11,100$8,600–$13,500
- Energy per year
- $710Baseline
- 15-year total
- $21,700
- Payback
- Baseline
Heat pump or new furnace and AC? For Rocky Mountain Power (PacifiCorp) customers
For Rocky Mountain Power (PacifiCorp) customers in Idaho, on the utility's average price, local weather.
Quick answer · updated
As of November 2026, for a typical 1,800 sq ft gas-heated home on Rocky Mountain Power (PacifiCorp) electricity rates in Idaho that needs a new furnace and AC: It depends on your quotes. A high-efficiency cold-climate heat pump costs about $100 a year more to run, so it only comes out ahead if its quote is at least $1,500 below the quote for a new furnace and AC.
Electricity
12.1¢/kWh
-5% vs. Idaho average
Heating fuel
$0.69/therm
Gas: 47% of homes here
Climate
8,825
heating degree days · Bern HCN
Rebates
Not checked
not yet researched in Idaho
Our estimate for this home
It depends on your quotes
It depends on your quotes. A high-efficiency cold-climate heat pump costs about $100 a year more to run, so it only comes out ahead if its quote is at least $1,500 below the quote for a new furnace and AC.
Total cost over 15 years
Installed cost plus energy, year by year. Hover or tap the chart to compare.
- New gas furnace + new AC
- Heat pump (replaces both)
- High-efficiency cold-climate heat pump
Show as a table
| Option | Installed cost (typical, range, after rebates) | Energy cost per year | 15-year total | Payback vs. like-for-like |
|---|---|---|---|---|
| New gas furnace + new AC Lowest 15-year cost | $11,100 $8,600–$13,500 |
$710 |
$21,700 | Baseline |
| Heat pump (replaces both) | $11,100 $7,700–$14,400 |
$1,210 costs $500/yr |
$29,200 | Same price up front, costs more to run |
| High-efficiency cold-climate heat pump | $14,400 $10,600–$19,200 |
$810 costs $100/yr |
$26,600 | Never pays back |
What this is based on
- Electricity: Rocky Mountain Power (PacifiCorp)'s average residential price in ID (EIA), $0.121/kWh; the winter price of extra kWh is estimated at $0.110/kWh. Enter your own rate for a closer answer.
- Weather: Bern HCN (8,825 heating and 139 cooling degree days a year, 1991-2020).
- Heating fuel prices (EIA): gas $0.69/therm (Idaho, average of the last five winter months); propane $2.66/gallon (Idaho average this heating season); heating oil $6.15/gallon (U.S. average this heating season).
- Homes in Rocky Mountain Power (PacifiCorp)'s Idaho area heat with gas 47%, electricity 34%, propane 12%, heating oil 2% (U.S. Census Bureau, American Community Survey 2019-2023). The calculator starts with gas, the most common furnace fuel here; pick yours above.
- Idaho HVAC installer wages are 8% below the U.S. median (BLS), so installed prices are scaled by 0.96.
- Energy use for heating and cooling:
- New gas furnace + new AC: 1,150 kWh and 843 therms a year for heating and cooling
- Heat pump (replaces both): 10,776 kWh a year for heating and cooling
- High-efficiency cold-climate heat pump: 7,162 kWh a year for heating and cooling
Rebates
- We haven't checked heat pump rebates in Idaho yet, so these numbers leave them out. Utility and state programs can take thousands off a heat pump: ask Rocky Mountain Power (PacifiCorp) and your contractor what's available. Each dollar of rebate adds a dollar to the quote gap a heat pump can carry.
How Rocky Mountain Power (PacifiCorp)'s rates change the answer
Rocky Mountain Power (PacifiCorp)'s electricity price for a typical home is 5% below the Idaho average ($0.121 vs. $0.128 per kWh). A heat pump moves your heating from gas, propane or oil to electricity, so the electricity price is the biggest single factor: calculators that use a state average can get the answer wrong for your utility. At these prices, gas heat is cheaper to run than a heat pump for a typical home here.
Common questions
Is a heat pump worth it for Rocky Mountain Power (PacifiCorp) customers?
It depends on your quotes. A high-efficiency cold-climate heat pump costs about $100 a year more to run, so it only comes out ahead if its quote is at least $1,500 below the quote for a new furnace and AC. This is for a typical 1,800 sq ft home with average insulation that heats with gas and needs both a new furnace and AC; change the details in the calculator above for your home.
How much does a heat pump cost to run on Rocky Mountain Power (PacifiCorp)'s rates?
About $810 a year for heating and cooling with a high-efficiency cold-climate heat pump (7,162 kWh), compared with about $710 a year for a new furnace and AC, for a typical 1,800 sq ft home with weather like Bern HCN's.
How much does a heat pump cost to install in Idaho?
Our typical installed price for a high-efficiency cold-climate heat pump in Idaho is about $14,415 (range $10,571 to $19,220), against about $11,052 for a new furnace and AC. Prices are published study ranges scaled for home size and Idaho installer wages; rebates in Idaho have not been checked yet, so they are not included. Always compare real quotes.
What electricity price does this use?
Electricity: Rocky Mountain Power (PacifiCorp)'s average residential price in ID (EIA), $0.121/kWh; the winter price of extra kWh is estimated at $0.110/kWh. Enter your own rate for a closer answer.
How we calculate this
Heating and cooling need
Your home's yearly heating and cooling need comes from 1991-2020 NOAA climate normals for the nearest weather station, scaled by floor area and insulation level. If you know last winter's gas use, compare it with the therms in the energy-use list above.
Heating fuels
Choose the fuel your furnace burns: gas, propane, heating oil or electricity. Gas uses the state's average residential price over the last five winter months; propane and heating oil use the U.S. Energy Information Administration's weekly residential prices for this heating season (state, regional or U.S. average, as available), converted by heat content (91,500 Btu per gallon of propane, 138,500 per gallon of oil). An electric furnace is priced through the same electricity rates as the heat pump. The starting fuel is the most common furnace fuel in the utility's area (U.S. Census Bureau, American Community Survey).
Equipment efficiency
New gas or propane furnace 95% AFUE, new oil furnace 85%, electric furnace 100%; new AC SEER2 13.4; standard heat pump SEER2 15.2 / HSPF2 7.8; high-efficiency cold-climate heat pump SEER2 21.5 / HSPF2 10.6. Heat pump efficiency falls as it gets colder, and in cold months part of the heat comes from backup electric strips (or your old furnace, if you keep it). Existing equipment is assumed to be 15-20 years old: an 80% gas or propane furnace, a 78% oil furnace or a SEER2 9.5 AC.
Installed costs
Installed prices vary a lot, so we show a typical price and a range for a home of about 1,800 sq ft with existing ductwork, scaled for larger or smaller homes: furnace and AC together $9,000–$14,000; furnace alone $3,800–$7,000; AC alone $4,500–$9,000; standard heat pump $8,000–$15,000; high-efficiency cold-climate heat pump $11,000–$20,000; electrical panel upgrade, if needed, $1,500–$4,000. These are national figures drawn from published studies and program data (NESCAUM / Energy Solutions, Heat Pumps in the Northeast and Mid-Atlantic: Costs and Market Trends (October 2024); Rewiring America, Upfront cost of home electrification (March 2024); EIA, Updated Buildings Sector Appliance and Equipment Costs and Efficiencies (2023)). The most useful number here is how much more a heat pump can cost than a like-for-like quote and still come out ahead: get quotes for both and compare.
Labor and rebates
Half of each installed price is treated as labor and scaled by the state's median HVAC installer wage relative to the U.S. median (U.S. Bureau of Labor Statistics). Listed rebates are subtracted when the box is ticked; per-ton rebates assume about one ton of capacity per 600 sq ft. Rebates change often and have eligibility rules, so confirm with the program before you buy.
Not included
Financing, maintenance (similar for all options), local town rebates, and changes in energy prices over time.