Heat pumps, sized & costed.
Find the capacity your home actually needs, then see what it costs to run versus a gas furnace — before any installer quote.
What size heat pump?
Estimate the heating and cooling capacity your home needs in BTU and tons.
Assumptions & sources
Capacity (BTU/h) = floor area × climate factor × insulation multiplier. Climate bands use typical 28/35/45 BTU per sq ft; 12,000 BTU = 1 ton. This is a rule-of-thumb estimate — a Manual J load calculation accounts for windows, orientation and air sealing for the final spec.
Gas vs heat pump — what runs cheaper?
Compare a year of heating on a gas furnace against a heat pump for your home.
Assumptions & sources
Annual heat demand = floor area × a climate factor (BTU/sq ft·yr). Gas cost = demand ÷ AFUE ÷ 100,000 × $/therm. Heat-pump cost = demand ÷ (COP × 3,412) × $/kWh. COP of 2.8 ≈ HSPF 9.5. Excludes cooling, standby and rate inflation; a heat pump also replaces a separate AC.
Heat pump questions, answered
Direct answers to what people ask before switching from gas.
What size heat pump do I need?
As a rule of thumb, homes need roughly 30 to 45 BTU per square foot depending on climate and insulation, so a 1,800 sq ft house often needs a 3 to 4 ton (36,000 to 48,000 BTU) heat pump. A proper Manual J load calculation refines this.
Is a heat pump cheaper to run than gas?
Usually yes. A modern heat pump delivers 2.5 to 3.5 units of heat per unit of electricity, so even where gas is cheap per unit, the efficiency advantage often makes heating costs lower — especially with high gas prices or moderate climates.
Do heat pumps work in cold weather?
Yes. Modern cold-climate heat pumps keep working well below freezing, often down to -15°C or colder, though efficiency drops as it gets colder. In very cold regions a backup heat source or a properly sized cold-climate unit is recommended.
How efficient are heat pumps?
Heat pumps are rated by HSPF for heating and SEER for cooling. A typical COP of 2.8 means they move nearly three units of heat for every unit of electricity used — far above the roughly 90 to 98% efficiency of a gas furnace, which can never exceed 100%.
Will a heat pump lower my energy bills?
For most homes replacing electric resistance or expensive heating fuels, yes, often substantially. Versus cheap natural gas the savings are smaller and depend on local rates, but a heat pump also adds efficient cooling, which gas heating cannot provide.