A furnace is the simplest and most reliable way to heat a home or commercial space with a ducted system. At AC Units For Less, we carry gas and electric furnaces from Goodman, Wrangler, and Daikin across all major efficiency tiers — from budget-friendly 80% AFUE models to high-efficiency 96%+ condensing units — so you can match the right equipment to your climate, budget, and long-term operating cost goals.
Every furnace in our inventory ships factory-direct to all 48 contiguous states. No local distributor markup. No upsell on equipment you don't need.
Gas Furnaces
Gas furnaces are the most common residential and light commercial heating choice across most of the U.S. They burn natural gas (or propane with a conversion kit) to generate heat, which is then distributed through your existing duct system by a blower motor. They're fast, powerful, and cost-effective to operate in most markets — especially in colder climates where a heat pump alone can't keep up.
The single most important spec on a gas furnace is its AFUE rating — Annual Fuel Utilization Efficiency. AFUE tells you what percentage of the fuel you burn actually becomes heat in your home. The rest goes up the flue as exhaust. We carry three efficiency tiers:
80% AFUE — Standard Efficiency
For every dollar of gas burned, 80 cents becomes heat and 20 cents exits as exhaust. This is the minimum efficiency allowed under federal standards for most of the country and is the right choice when upfront cost is the priority, when the furnace is in a conditioned space (so flue heat loss matters less), or when the home is in a mild climate where the furnace doesn't run heavily. 80% units use a single-pipe venting system — conventional metal flue — which simplifies installation and makes them a clean drop-in replacement for older equipment in most homes. Models available from 40,000 to 120,000 BTU.
92% AFUE — Mid Efficiency
92% AFUE units convert 92 cents of every gas dollar into usable heat — a meaningful improvement over 80% that translates directly to lower monthly gas bills without the full cost jump of a condensing unit. These models typically use a two-stage or variable-capacity gas valve paired with a multi-speed ECM blower motor, which means they modulate output based on the actual heating demand rather than always running at full blast. The result is more even temperatures, quieter operation, and better humidity control compared to single-stage 80% units. Good fit for climates with moderate to cold winters where the furnace runs regularly from November through March. Still uses conventional flue venting. Models available from 40,000 to 120,000 BTU.
96%+ AFUE — High Efficiency Condensing
High-efficiency condensing furnaces extract so much heat from the combustion gases that the exhaust cools down to the point of condensing — which is why they vent through PVC pipe rather than a metal flue. That's a key installation consideration: if you're replacing an 80% unit, you'll need to add PVC vent pipes (typically two — one combustion air intake, one exhaust), which adds some installation complexity but eliminates the heat loss of a conventional flue entirely. At 96%+ AFUE, these units are the right long-term choice in cold climates with high heating loads, for homeowners focused on minimizing operating costs, or for new construction where PVC venting can be planned from the start. Many models qualify for utility rebates and federal tax credits. Variable-speed ECM blower motors are standard at this tier. Models available from 40,000 to 120,000 BTU.
Low NOx and Ultra Low NOx
Nitrogen oxide (NOx) emissions from gas combustion are regulated in certain air quality management districts — most notably California's South Coast AQMD and Bay Area AQMD, which require Low NOx (40 nanograms/joule or less) or Ultra Low NOx (14 ng/J or less, required in many California districts as of 2020) certified equipment for residential installation. If you're purchasing a furnace for a property in California, confirm your local district's current NOx requirement before ordering. We carry Daikin furnaces certified to both Low NOx and Ultra Low NOx standards for California compliance. If you're outside California, standard models apply — NOx restrictions do not currently affect most other U.S. markets, though some states are moving in this direction. Not sure what your jurisdiction requires? Call us at 678-535-7176 and we'll confirm before you order.
Electric Furnaces
Electric furnaces use resistance heating elements — essentially large, heavy-duty versions of the element in an electric oven — to generate heat, which the blower then distributes through your duct system. There's no combustion, no flue, no gas line, and no risk of carbon monoxide. Installation is simpler than gas in buildings without existing gas service, and the units themselves are typically less expensive upfront.
The trade-off is operating cost. Electric resistance heating is significantly more expensive per BTU than gas in most U.S. markets, which is why electric furnaces are most commonly used in mild climates where the heating load is relatively light (the Southeast and Southwest particularly), in homes and buildings without gas service, or as the backup heat source in a heat pump system where the electric furnace only runs during the coldest days when the heat pump can't keep up on its own.
Electric furnaces don't carry an AFUE rating the same way gas units do — they're effectively 100% efficient at point of use since all electrical energy converts to heat with no exhaust losses. The real efficiency question is upstream: how the electricity itself is generated. For homes with solar or in markets with low electricity rates, electric furnaces are a practical choice. Models available from Intertherm/Nortek in sizes compatible with standard residential duct systems.
How to Choose the Right Furnace
Three decisions drive the right choice: fuel type (gas vs. electric), BTU size, and AFUE tier.
For BTU sizing, the general rule is 30–60 BTU per square foot depending on climate severity, ceiling height, and insulation level. A 1,500 sq ft home in Georgia needs around 45,000–60,000 BTU. The same home in Minnesota needs 60,000–80,000 BTU. Oversizing is a common mistake — an oversized furnace short-cycles, wears out faster, and creates uneven temperatures. Our team can help you size correctly before you order.
For AFUE tier, a rough payback rule: upgrading from 80% to 96% typically pays back in 5–8 years in a cold climate running 1,500+ heating hours per season. In a mild climate running 500 heating hours, the payback stretches to 15+ years and the 80% unit makes more financial sense.
Need help deciding? Call 678-535-7176 or use our free estimate form. Contractor and volume pricing is available through our B2B program.
Gas Furnaces — 80%, 92% & 96%+ AFUE, 40,000–120,000 BTU
We carry gas furnaces from Goodman, Wrangler, and Daikin across three efficiency tiers and a full range of BTU outputs. All units are brand new, ship factory-direct, and come with full manufacturer warranties. Whether you're replacing a failed furnace on a tight timeline or spec'ing equipment for a new install, you'll find the right unit here without the distributor markup.
Choosing Your AFUE Rating
80% AFUE — The right choice when upfront cost matters most, when the climate is mild, or when you're doing a straightforward swap on an existing conventional-flue system. Single-pipe metal venting. Reliable, simple, and widely serviceable. Goodman's 80% lineup runs from 40,000 to 120,000 BTU in single-stage and multi-speed ECM configurations.
92% AFUE — A meaningful efficiency step up that doesn't require changing your venting setup. Multi-speed ECM blower motors are standard at this tier, giving you more even heat distribution and quieter operation than single-stage 80% units. The sweet spot for homeowners in moderate-to-cold climates who want better efficiency without the venting changes required by a condensing unit.
96%+ AFUE — Condensing furnaces that vent through PVC pipe rather than a metal flue, extracting maximum heat from combustion gases before they exit the building. Best long-term operating cost in cold climates with heavy heating loads. Variable-speed ECM blower motors standard. Many models qualify for utility rebates and federal tax incentives. Plan for PVC venting if replacing an 80% or 92% unit.
Low NOx & Ultra Low NOx
Installing in California? NOx emission requirements vary by air quality district. Many California districts now require Ultra Low NOx certified furnaces (14 ng/J or less) for residential installation — standard models will not pass inspection. We carry Daikin furnaces certified to both Low NOx and Ultra Low NOx standards. Confirm your district's current requirement before ordering — we can help verify if you're unsure. Outside California, standard models apply.
Questions about sizing, venting, or California NOx compliance? Call 678-535-7176. Volume and contractor pricing through our B2B program.
Electric Furnaces — Duct Heating Without Gas
An electric furnace heats your home through resistance heating elements inside the cabinet, with the blower distributing that heat through your existing duct system — no gas line, no flue pipe, no combustion, and no risk of carbon monoxide. If your building doesn't have gas service, or if you're adding a backup heat source to a heat pump system, an electric furnace is the clean, straightforward solution.
When an Electric Furnace Makes Sense
No gas service: The most common reason. Running a new gas line to a building adds cost and permitting complexity. An electric furnace installs with standard electrical service — no gas plumber, no line extension, no meter upgrade required beyond the electrical panel capacity for the unit's amperage draw.
Heat pump backup (emergency heat): Most ducted heat pump systems pair with an air handler that has electric heat strips built in — but standalone electric furnaces are also used as backup heating in heat pump systems, particularly in retrofit applications where the heat pump is being added to an existing forced-air setup. When outdoor temperatures drop too low for the heat pump to meet setpoint efficiently, the electric furnace carries the load.
Mild climates: In the Southeast, Gulf Coast, and Southwest, heating loads are light enough that the higher operating cost of electric resistance heat doesn't add up to a significant annual expense. A homeowner in South Florida running their furnace 200 hours a year pays far less in operating cost than a homeowner in Ohio running it 1,500 hours — which makes the lower upfront cost of an electric furnace more attractive.
A Note on Operating Costs
Electric resistance heating converts all electricity to heat at point of use — there are no exhaust losses, so it's effectively 100% efficient by the AFUE measure. But electricity costs more per BTU than natural gas in most U.S. markets. If your building has gas service and you're in a climate with significant heating loads, a gas furnace will typically cost less to operate over time. If you're weighing options, call us — we can help you run the numbers for your specific climate and utility rates.
Need help selecting the right unit or confirming compatibility with your air handler? Call 678-535-7176. Contractor and volume pricing available through our B2B program.
