By Hood Service Company · Corsicana, TX · Updated
The short version
- A heat pump replaces both the AC and the furnace, while a furnace still needs an AC for summer.
- A furnace's output holds steady in a hard freeze, while a heat pump relies on backup heat on the coldest days.
- Running cost depends on your local electric and gas rates and the efficiency of each system.
- A dual-fuel system pairs a heat pump with a furnace and uses each where it's strongest.
What's the core difference between a heat pump and a gas furnace?
A heat pump uses electricity to move heat from outdoor air into your home. A gas furnace makes heat by burning natural gas or propane and blowing air across a heat exchanger.
A furnace's efficiency is rated by AFUE, the share of fuel energy turned into usable heat. A heat pump's heating efficiency is rated by HSPF2 and its cooling by SEER2. Our guide to how heat pumps work covers the basics.
How do they compare in a North-Central Texas winter?
On mild days, a heat pump is typically very efficient. In a hard freeze, a furnace's output stays steady while a heat pump leans on backup heat. Most winters here are mild, with occasional deep cold.
- Heat pump: steady, moderately warm air, longer cycles, periodic defrost in cold and damp weather, and backup heat for the coldest hours.
- Gas furnace: hotter air at the vents, shorter cycles, and output that doesn't fall off as the outdoor temperature drops.
- Power outages: both need electricity for the blower and controls, so neither heats the house without power.
Which one costs less to run?
It depends on your electric and gas rates, the efficiency of each system and how cold the winter gets. There's no single answer, so compare using your own utility bills and the ratings on each quote.
Look at the whole year. With a furnace, you still need a central AC for summer, and in this climate cooling is usually the bigger energy job. That makes a heat pump's SEER2 rating as important as its heating rating. The SEER calculator helps compare cooling efficiency levels, and your installer should walk you through heating costs for your home.
What safety and installation factors differ?
A gas furnace needs a gas supply, proper venting and combustion safety checks; a heat pump has no flame or flue. Either way, Texas HVAC work must be done by a contractor licensed through TDLR.
Homes with a gas furnace should keep working carbon monoxide alarms. If you ever smell gas, leave the house first, then call your gas utility or 911 from outside. Switching fuel types changes more than the equipment, so have the whole job scoped before you decide. Hood pulls the required HVAC permits for the installations we do.
When does a dual-fuel system make sense?
A dual-fuel, or hybrid, system pairs a heat pump with a gas furnace. The heat pump handles cooling and mild-weather heating, and the furnace takes over when it gets cold.
It can suit homes that already have gas service and want a heat pump's efficiency without relying on electric backup heat in a freeze. The thermostat or system control decides when to switch. See hybrid systems in our glossary.
How do you decide which is right for your home?
Start with what the house already has: gas service, the condition of the ductwork, the age of your AC and a proper load calculation. Then compare quotes for each option at similar efficiency levels.
We can quote either option. Start with heat pump installation and replacement or request a free estimate. Financing is available, subject to credit approval and lender terms.
- No gas service: a heat pump is usually the simpler path.
- Gas service and an aging furnace and AC: price both a heat pump and a dual-fuel option.
- Sizing first: read our guide to HVAC sizing and load calculations before comparing equipment.
When should you call a technician?
- You smell gas near the furnace. Leave the house first, then call your gas utility or 911 from outside.
- A carbon monoxide alarm sounds. Get everyone outside, then call 911.
- Heat pump aux heat runs constantly in mild weather.
- The furnace lights, shuts off within minutes and repeats.
- You see soot or scorch marks around the furnace or its vent.
Frequently asked questions
Can I add a heat pump to my existing gas furnace?
Often, yes, if the furnace and ductwork are in good shape and the equipment is compatible. The heat pump replaces the outdoor AC unit and works with the furnace as a dual-fuel system. A technician needs to confirm compatibility and sizing first.
Does a heat pump keep working in a Texas ice storm?
It keeps running, but its output drops and backup heat carries more of the load. Frost on the outdoor coil triggers defrost cycles. If the unit is encased in ice, switch to emergency heat if your thermostat has it and call for service.
Do I need new ductwork to switch from a furnace to a heat pump?
Not necessarily. Both use the same kind of ductwork, but a heat pump's air is cooler and it can need more airflow, so undersized or leaky ducts show up more. Have the ducts checked as part of the quote.