How a Heat Pump Works

LearnCooling & Heating Basics

By Isabel Rodriguez, Vice PresidentUpdated June 20266 min read

A heat pump is an AC that can run in reverse to heat your home. In a mild climate like South Texas, that makes it an efficient way to do both jobs.

A heat pump is an air conditioner that can run in reverse. In summer it pulls heat out of your home like any AC; in winter it reverses, pulling heat from the outdoor air and moving it inside. Because it moves heat instead of burning fuel, it's an efficient way to handle both jobs in a mild climate.

How can it heat if it's pulling heat from cold air?

Even cool outdoor air holds usable heat energy. A reversing valve flips the refrigerant flow so the outdoor coil absorbs that heat and the indoor coil releases it. On the Valley's coldest nights, an electric backup (a heat strip) gives it a hand — but those nights are few here.

Why is a heat pump a good fit for South Texas?

We cool far more than we heat, and a heat pump is excellent at cooling.
Our winters are mild, which is exactly where heat pumps are most efficient.
One system does both jobs — no separate furnace and no gas line required.

For homes that rarely see a hard freeze, this often makes more sense than a furnace. See do I even need heat in South Texas?

Heat pump vs. a standard AC — what's the real difference?

A standard AC only cools; for heat you'd add a furnace or electric strips. A heat pump cools and heats in one system. If you're choosing for a new install or replacement, weigh them side by side in AC vs. heat pump, and budget with our heat pump cost guide.

What's next?

Whether a heat pump is right for your home depends on your existing setup, insulation, and how you use it. Book a free estimate and we'll lay out your options with no pressure — including financing if you're replacing a whole system.

Terms in this article

Plain-language definitions — see the full HVAC glossary.

Heat Pump: An AC that can run in reverse to heat as well as cool. Because it moves heat instead of burning fuel, a heat pump is an efficient way to handle both jobs in a mild climate like South Texas.
SEER2: Seasonal Energy Efficiency Ratio 2 — the current U.S. rating for how efficiently an AC or heat pump cools over a season. It replaced the old SEER scale in 2023 using a tougher, more realistic test. Higher SEER2 means lower running cost for the same cooling.
HSPF2: Heating Seasonal Performance Factor 2 — the heating-efficiency rating for a heat pump. The higher the HSPF2, the less electricity the heat pump uses to keep you warm on the Valley's few cold nights.
Refrigerant: The chemical that absorbs heat indoors and releases it outdoors as it cycles through your system. If your system is low on refrigerant, it usually means there's a leak — adding more without fixing the leak is only a temporary patch.

Written & reviewed by Isabel Rodriguez, Vice President

Isabel Rodriguez helps lead Angels Cooling LLC, a family-owned, TDLR-licensed HVAC company serving Harlingen and the Rio Grande Valley. Have a question this guide didn't answer? Ask our team.