Furnace Installation in Duncan, OK
A new furnace here will run from November through April every year. Tell us about the house, and a licensed contractor who covers Stephens County will get in touch.
Tell us about the job
It takes about a minute.
What winter in Duncan asks of a furnace
Your furnace has six months of work ahead of it, November through April. Winter nights average 31°F, and the burner has to answer for that night after night. That's not a brutal cold by national standards, but it's steady, and steady is what wears a furnace down.
A new furnace installed here has to meet the federal minimum of 80.0 percent AFUE if it's a non-weatherized gas model, so that part is settled for you. What's worth thinking about is the power behind it. Stephens County has seen 67 damaging wind events and 6 winter storms over the past ten years, and a quarter of Oklahoma households lost power for at least 24 hours in 2024. A furnace with no power won't light, no matter how new it is, so if outages are a real concern where you are, that's a conversation worth having when you plan the install.
- 6 months
- November through April, your furnace is on duty
- 31°F
- the average winter night it heats against
- 80% AFUE
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
Oklahoma requires HVAC contractors to hold a state license.
The license comes from the Construction Industries Board, and it covers the contractor, not the job in front of them. That means the state tested this person before they were allowed to call themselves an HVAC contractor, and there is a record of who they are. It does not mean an inspector signs off on your furnace when the work is finished.
That check comes from somewhere else. In most cities and counties, putting in a new furnace needs a permit from the local building office, and an inspection once the work is done. That inspection is what catches a bad gas connection or a vent that was not run right, the part of this job where a mistake actually puts a house at risk. The license tells you the contractor was tested. The permit and inspection tell you this furnace was checked.
Source: Oklahoma State Legislature
- What size furnace does my house need?
- It depends on your square footage, your insulation, your windows, and your home's layout, so there is no number that fits every house. A contractor sizes a furnace with a load calculation that looks at all of those things together. Going by square footage alone leads to a furnace that is too big or too small, and either one costs you comfort. Get the calculation done for your house rather than guessing from a chart.
- How do I know it's time to replace my furnace?
- If your furnace needs repairs more than once a season, or it can't keep rooms warm on the coldest nights, it's time to start planning a replacement. Winter nights here average 31°F, and homes need heat from November through April, so a furnace that is struggling has no real break to recover in. Rising gas bills with no other explanation are another sign the furnace is losing efficiency. A contractor can tell you whether a repair still makes sense or whether the furnace has reached the end of its service life.
- Is a high-efficiency furnace worth it?
- For a house that needs heat six months of the year, a high-efficiency furnace burns less gas to produce the same warmth, month after month. Furnaces made since November 2015 are already required to hit at least 80 percent AFUE, so the question is whether it makes sense to go beyond that minimum for your house. Higher-efficiency models vent differently, which can affect how they are installed. A contractor can walk you through the options for your house and price out the difference.