Heat Pump Energy Calculator

Heat pump electricity consumption depends on three factors: system size (tonnage), outdoor temperature, and efficiency rating (SEER2/HSPF2). Understanding typical wattage ranges helps you plan for operating costs, solar system sizing, and battery backup capacity.

Typical Wattage by System Size

At moderate heating conditions (47°F outdoor temperature), expect these wattage ranges:

• 2-ton heat pump: 2,400-3,600 watts
• 3-ton heat pump: 3,000-4,500 watts
• 4-ton heat pump: 4,000-6,000 watts
• 5-ton heat pump: 5,000-7,500 watts

Higher-efficiency models (above 10 HSPF2) typically fall in the lower half of these ranges. Cold-climate units with enhanced vapor injection use slightly more wattage but deliver substantially more heating capacity at low temperatures.

How Temperature Affects Electricity Use

Wattage increases as outdoor temperature drops, but not linearly. Heat pumps use a metric called COP (Coefficient of Performance): the ratio of heat output to electrical input. At 47°F, a cold-climate heat pump achieves a COP of 3.5-4.5 (350-450% efficiency). At 5°F, COP drops to 2.0-2.8 (200-280% efficiency).

This means a 3-ton heat pump drawing 3,500 watts at 47°F might draw 6,000-7,000 watts at 5°F to deliver the same heating output. However, Denver's climate is moderate: 75% of winter hours occur above 25°F, where efficiency remains excellent. Only about 400 hours annually drop below 10°F.

Denver-Specific Monthly Usage Patterns

Our calculator uses TMY3 (Typical Meteorological Year) climate data for Denver to estimate realistic consumption. For a typical 2,000 sq ft home with a properly sized heat pump:

• Heating season (December-February): 600-1,200 kWh/month, depending on insulation and thermostat settings
• Shoulder months (March, April, October, November): 200-400 kWh/month for heating and cooling combined
• Cooling season (June-August): 300-600 kWh/month, with July typically peaking
• Mild months (May, September): 100-250 kWh/month

Total annual consumption for heating and cooling combined: 5,000-10,000 kWh, with the range determined by home size, insulation quality, and temperature preferences. Use the calculator above to model your specific equipment and usage patterns.

Operating costs follow Denver's seasonal temperature patterns. At Xcel Energy's current residential rate (approximately $0.14/kWh including all fees), monthly costs break down as follows for a typical 2,000 sq ft home:

Peak Heating Months (December-February)

January is typically the highest cost month, with outdoor temperatures averaging 30-35°F and occasional cold snaps below 10°F. Expect $85-170/month for heat pump operation alone. Homes with excellent insulation and moderate thermostat settings (68-70°F) stay toward the lower end. Older homes with air leakage and higher thermostat settings (72-74°F) trend higher.

Peak Cooling Months (June-August)

July cooling costs typically run $40-85/month. Cooling is substantially cheaper than heating in Denver's climate because outdoor temperatures rarely exceed 95°F, and cooling degree days are far fewer than heating degree days. Homes with west-facing exposure and high cooling demand trend toward the upper range.

Shoulder Seasons (Spring and Fall)

March, April, October, and November see minimal heating and cooling needs. Monthly costs often drop to $15-40. These months represent Denver's "free conditioning" window when outdoor temperatures align closely with indoor comfort levels.

How Our Calculator Uses Real Climate Data

Rather than using national averages, our calculator analyzes Denver's actual weather patterns: hourly temperature distributions, heating degree days, and cooling degree days from TMY3 data. It matches your selected heat pump's AHRI-rated performance at specific temperatures (17°F, 5°F, 47°F for heating; 82°F, 95°F for cooling) to estimate month-by-month consumption.

The result is a realistic cost projection that accounts for Denver's moderate climate, high altitude, and significant diurnal temperature swings. This level of accuracy matters when comparing heat pumps to gas furnaces or planning solar offset.

The question is not whether heat pumps use electricity, but whether they use it efficiently. Heat pumps consume less electricity than any other electric heating option, and they often cost less to operate than gas furnaces when you account for total utility bills.

Heat Pump vs. Electric Resistance Heat

Electric baseboard heaters, wall heaters, and space heaters operate at 100% efficiency: one watt of electricity produces one watt of heat (3.41 BTU). Heat pumps operate at 200-400% efficiency by moving existing heat rather than creating it. At 47°F, a heat pump delivers 3-4 watts of heat for every watt consumed. Even at 5°F, it delivers 2-2.8 watts of heat per watt consumed.

For a 2,000 sq ft Denver home, annual heating costs compare as follows:

• Electric baseboard/resistance heat: $1,200-2,000/year
• Cold-climate heat pump: $400-700/year

The heat pump uses 60-70% less electricity to achieve the same heating output. This efficiency gap is why utilities like Xcel Energy offer rebates for heat pump installations: electrification with heat pumps reduces overall grid demand compared to resistance heating.

Heat Pump vs. Gas Furnace

This comparison is more nuanced because natural gas and electricity are priced differently. A 95% AFUE gas furnace is extremely efficient at converting fuel to heat, but natural gas prices and carbon intensity matter. In Denver, the calculation looks like this:

• Gas furnace (95% AFUE): $450-650/year in gas costs, plus $50-100/year in electricity for the blower, totaling $500-750/year
• Heat pump: $400-700/year in electricity, no gas costs

At current utility rates, heat pumps and high-efficiency gas furnaces cost approximately the same to operate. However, heat pumps eliminate gas infrastructure costs (meter fees, connection fees), provide air conditioning without additional equipment, and position you to benefit from future solar or battery installations.

When Cold-Climate Heat Pumps Are Worth It

Standard heat pumps lose efficiency below 40°F and require backup heat below 25°F. Cold-climate heat pumps maintain efficiency down to 5°F and operate without backup to -10°F or lower. In Denver's climate, where 75% of winter hours occur above 25°F, a cold-climate unit rarely needs backup heat.

The efficiency advantage is measurable: a cold-climate heat pump maintains COP 2.5-3.0 at 17°F, while a standard heat pump drops to COP 1.5-2.0 and requires resistance heat backup. Over a Denver winter, this translates to 20-30% lower electricity consumption for the same heating output.

If you're replacing electric resistance heat, any heat pump is a massive upgrade. If you're replacing a gas furnace or choosing between heat pump models, invest in a cold-climate unit with HSPF2 above 10. The efficiency gains pay back the premium within 3-5 years.

Heat pump wattage varies significantly based on outdoor temperature, system size, and efficiency rating. At rated conditions (47°F), a typical 3-ton cold-climate heat pump draws 3,000-4,500 watts. As temperatures drop, wattage increases: at 5°F, the same unit may draw 5,000-7,000 watts.

This relationship matters for two reasons: operating costs and backup power sizing. In Denver's climate, your heat pump spends most winter hours operating between 25-45°F, where efficiency is excellent and wattage is moderate. The coldest hours (below 10°F) represent only about 400 hours annually (less than 5% of the year).

Our calculator uses AHRI-certified performance data for each model, combined with TMY3 (Typical Meteorological Year) climate data for Denver, to estimate realistic annual operating costs and energy consumption patterns.

Yes: with proper sizing and expectations. Denver averages 5.5 peak sun hours daily, making it an excellent solar market. A 6-8 kW solar system (15-20 panels) can typically offset 80-100% of a heat pump's annual electricity consumption.

The catch: production peaks in summer when heat pump usage is lowest, and drops in winter when heating demand is highest. Net metering with Xcel Energy allows you to bank summer credits to offset winter bills. The result is a near-zero annual electricity bill for heating and cooling combined.

Use our solar offset calculator above to see monthly production vs. consumption patterns for your specific heat pump model.

Battery backup for heat pumps requires careful sizing. Unlike refrigerators or lights, heat pumps have significant startup surges and variable runtime based on temperature. The Tesla Powerwall 3 (13.5 kWh, 11.5 kW continuous) is popular because it handles both the startup surge and sustained draw of most residential heat pumps.

Runtime depends heavily on outdoor temperature and your home's insulation. At 35°F with typical duty cycles (60% runtime), a Powerwall can run a heat pump for 16-24 hours. At 5°F with continuous operation, expect 6-10 hours. Pairing batteries with solar extends this significantly during daytime outages.

For critical backup needs, we recommend consulting with our team to properly size battery capacity for your specific equipment and comfort requirements.