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The fundamental idea — moving heat, not making it
Every furnace and every electric strip heater makes heat by converting fuel or electricity into thermal energy. Burn a molecule of natural gas, get a fixed amount of heat. Push a kilowatt through a resistance element, get 3,412 BTU of heat. Simple, one-to-one, and unavoidably capped at 100% efficient (in the case of electric resistance) or slightly less (in the case of gas, which loses some heat up the flue).
A heat pump doesn't make heat. It moves heat that already exists from one place to another. That's a fundamentally different process, and it's why a heat pump can deliver 2-4 units of heat energy into your house for every 1 unit of electricity it consumes. You're not violating physics — you're not creating energy — you're just harvesting heat that was outside and relocating it inside.
The best analogy is your kitchen refrigerator. A fridge takes heat from inside the cold box, moves it to the coil on the back, and dumps that heat into your kitchen. That's why the back of the fridge is warm and the inside is cold. A heat pump is the same machine, just larger, plumbed to your house, and with a switch that reverses which side is "the cold box" and which side is "the warm kitchen." In cooling mode, your house is the cold box and the outdoor unit is the kitchen. In heating mode, the outdoor unit is the cold box and your house is the kitchen.
The refrigeration cycle in three moves
Inside every heat pump (and every AC, and every fridge) is a closed loop of refrigerant continuously cycling through four components. Follow one molecule of refrigerant through one lap:
- 1
Move 1 — Absorb heat at the cold coil (the evaporator)
Cold, low-pressure liquid refrigerant enters the evaporator coil. The refrigerant is much colder than the air blowing across the coil (yes, even winter outdoor air at 30°F is warmer than a refrigerant at 15°F). Heat flows naturally from warmer to colder — the air gives up its heat to the refrigerant, which boils and turns from liquid into a cold vapor.
- 2
Move 2 — Compress the vapor
The cold refrigerant vapor is pulled into the compressor. The compressor squeezes it into a much smaller volume. Compressing a gas heats it up (same reason a bike pump gets hot). Now you have a very hot, high-pressure vapor — carrying all the heat it collected from Move 1 PLUS the heat added by the compression work.
- 3
Move 3 — Release heat at the hot coil (the condenser)
The hot vapor enters the condenser coil, which is now cooler than the vapor itself. Heat flows out of the refrigerant, into the air blowing across the condenser. The refrigerant condenses back into a liquid. Then a metering device (a TXV or an expansion valve) drops its pressure, which drops its temperature, and it heads back to Move 1 as cold liquid.
That's the whole trick. Absorb heat where it's cold, compress to concentrate it, release heat where it's warmer. Repeat continuously.
The reversing valve is the one part that makes a heat pump different from an AC. It's a four-way valve that swaps the refrigerant flow direction. In cooling mode, the indoor coil is the evaporator (absorbs heat from your house) and the outdoor coil is the condenser (releases heat outside). Flip the reversing valve for heating mode and the roles swap: the outdoor coil becomes the evaporator (absorbs heat from outside), the indoor coil becomes the condenser (releases heat into your house).
Why heat-pump "efficiency" can exceed 100%
This is the number that trips people up: a modern heat pump has a rated Coefficient of Performance (COP) of 3 to 4 in heating mode. A COP of 3 means: for every 1 kilowatt-hour of electricity the heat pump uses, it delivers 3 kilowatt-hours of heat into your house. Which sounds impossible. It's not.
The math works because the heat pump isn't converting electricity into heat 1:1. It's using electricity to run a pump that moves heat from outside to inside. The heat itself isn't coming from the electricity — it's coming from the outdoor air. Of the 3 kWh of heat you get in the house, 1 kWh came from the compressor work (electricity → heat) and 2 kWh came from the outdoor air. That extra 2 kWh isn't free energy in a thermodynamic sense — you're just moving heat that was already there.
Compare that to:
| Heat source | Delivered heat per 1 kWh input | Effective efficiency |
|---|---|---|
| Electric strip heat (baseboards, back-up strips) | 1.0 kWh | 100% |
| High-efficiency gas furnace (96% AFUE) | n/a (fuel unit) | 96% of fuel content |
| Older heat pump (COP 2.5) | 2.5 kWh | 250% |
| Modern variable-speed heat pump (COP 3.5+) | 3.5+ kWh | 350%+ |
Where the physics gets harder — very cold air
The intuitive objection: "if there's no heat outside, how can a heat pump pull heat in?" The answer is that "cold" is a relative term. Even 0°F air contains a lot of absolute thermal energy — cold on a Fahrenheit thermometer is still 460°F above absolute zero on the Rankine scale. There is always heat to move; the question is just how efficiently you can move it as the source gets colder.
As outdoor temperature drops, three things happen to a heat pump:
- The refrigerant has less heat to absorb per pass, so the system needs more passes (more compressor run time) to deliver the same amount of heat to the house.
- The compressor works harder against a bigger temperature differential, drawing more electricity per unit of heat delivered.
- At some point (the "balance point"), the heat pump's output equals the house's heat loss and the system can't gain ground on setpoint by itself.
Older heat pumps (1990s-2000s technology) hit their balance point around 30-35°F. Below that, homeowners saw the electric-resistance backup strips kick in, and the electric bill went up. That's where the "heat pumps don't work in the cold" reputation came from — and it was fair, for that era.
Modern cold-climate heat pumps (variable-speed inverter compressors, enhanced vapor injection, larger outdoor coil surface area) have balance points down around 5-15°F. Below that, backup heat is still needed, but for the great majority of the heating season the heat pump is doing all the work by itself, at high COP. In Van Buren, where January lows average 30°F and it drops below 15°F for maybe 20-40 hours in a typical winter, a modern heat pump is nearly always operating in its efficient range.
For the local case specifically, see our full walkthrough of heat pumps in Van Buren winters.
Terms you'll see on a quote
Enough terminology to read a heat-pump quote without a translator:
SEER2
Cooling efficiency, updated 2023 test standard. Higher is better. Modern residential heat pumps are 15-22 SEER2. See our SEER2 explainer for what the 2023 change meant.
HSPF2
Heating efficiency, updated 2023 test standard. Higher is better. Modern residential heat pumps are 7.5-10 HSPF2. Roughly analogous to SEER2 but on the heating side.
COP (Coefficient of Performance)
Instantaneous heat-output-to-electricity-input ratio at a specific outdoor temperature. A COP of 3 means 3× as much heat delivered as electricity consumed. Manufacturers publish COP curves at 47°F, 17°F, and 5°F for cold-climate qualification.
Balance point
The outdoor temperature below which the heat pump alone can't keep up with heat loss and backup heat starts contributing. Sizing to a lower balance point costs more upfront but saves on operating cost.
Auxiliary / emergency heat
The backup heat source — usually electric resistance strips in the air handler, or in a "dual-fuel" setup, a gas furnace. Only runs at very cold temperatures or during defrost.
Defrost cycle
A short cycle (usually 5-10 minutes) where the heat pump reverses to melt frost off the outdoor coil. Happens automatically. During defrost the indoor supply air is cool for a few minutes.
Variable-speed / inverter compressor
A compressor that runs at any speed from about 25% to 100% capacity, matching output to demand. Delivers steadier temperatures, lower run-hours at high load, and much better efficiency in mild weather. Standard on cold-climate models.
When a heat pump makes sense — and when it doesn't
The short version:
Excellent fit — new construction, addition, or aging AC + furnace
One piece of equipment, both seasons, high efficiency, eligible for Federal 25C credit and SWEPCO rebates. In Van Buren the math almost always works.
Great fit — home without gas access
If your only alternative is electric-resistance heat, a heat pump cuts winter electric bills 50-70%. This is the biggest single upgrade many all-electric homes can make.
Marginal fit — existing high-efficiency gas furnace under 10 years old
The gas furnace still has plenty of life. A heat pump replacement now is fine but doesn't have as strong a payback. Worth evaluating when the AC side needs replacement anyway.
Not a fit — no ductwork AND awkward floor plan for ductless
Heat pumps still work here, but the install cost gets bigger. Sometimes a targeted mini-split for the worst rooms plus keeping existing heat is a better path.
For a full side-by-side comparison, our AC + furnace vs. heat pump guide is the deeper read.
Frequently asked
Is a heat pump just an AC? +
Mechanically, almost yes. A heat pump is an AC with an added reversing valve and slightly different controls. Run in cooling mode, a heat pump and an AC are indistinguishable — same efficiency, same performance. What you're paying for on the heat-pump side is the ability to run the cycle in reverse for winter heat.
Why does the indoor air feel cooler from a heat pump than from a furnace? +
Because a heat pump delivers supply air at 90-100°F while a gas furnace delivers 120-140°F. Both keep your house at setpoint, but the furnace air feels hot on skin (above body temp) and heat-pump air feels neutral (below body temp). No comfort difference at steady state — the house is 70°F either way.
Does a heat pump cost more to run than a gas furnace? +
Depends on local electric and gas rates and the equipment's efficiency. In Van Buren, on current SWEPCO electric rates and current natural-gas pricing, a modern high-efficiency heat pump is usually competitive with or slightly better than a 90%+ AFUE gas furnace. All-electric homes see a big improvement over resistance heat.
How long does a heat pump last? +
Heat pumps typically live 12-15 years, similar to a central AC. They run more hours per year than an AC-only system (they work in both seasons), which is one reason regular maintenance matters more than for a single-season unit. Compressor and coil quality are the two biggest lifespan drivers.
Do I need backup heat with a heat pump in Van Buren? +
Yes — every code-compliant heat pump install includes an auxiliary heat source. In Van Buren that's usually electric resistance strips (a few kW in the air handler) or a paired gas furnace in a dual-fuel arrangement. Backup heat runs a small handful of hours per winter here — enough to be worth having, not enough to dominate operating cost.