All three are about 97% efficient. So what are you paying more for?
Comfort, Performance and Infinity sit almost level on efficiency. The difference is how steadily they heat. Here is what separates the Carrier furnace series.
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Quick answer
The Carrier furnace series differ by how they stage heat, not by how efficient they are. Comfort is single-stage. Performance is mostly two-stage with a 25-speed blower. Infinity adds a modulating gas valve with 60 settings and a communicating control. All three reach roughly 97% AFUE.
Key takeaways
- Efficiency is not the dividing line. Carrier lists Comfort and Performance at up to 97% AFUE and Infinity at up to 98.5%.
- What you gain going up the range is steadier temperature, quieter operation and finer humidity control.
- A communicating control only comes with Infinity. Performance pairs with an ecobee smart thermostat for Carrier instead.
- In a drafty or exposed house, staging matters more than the efficiency rating.
- Sizing and ductwork decide more than the series does. A premium furnace on undersized return air still disappoints.
What are the three Carrier furnace series?
Carrier sells residential gas furnaces in Canada under three names. Comfort is the entry range, which Carrier itself calls budget-friendly. Performance sits in the middle and is described as the best of both worlds. Infinity is the premium range, which Carrier says delivers its highest efficiency and most innovative comfort features.
The names describe tiers, not technologies, so two furnaces in the same series can behave differently. The specification that matters is how the burner stages and how the blower runs.
Is the Infinity series actually more efficient?
Only slightly, and that surprises most homeowners. Carrier lists the Comfort series at up to 97% AFUE and the Performance series at up to 97%. The Infinity series tops out higher, up to 98.5% on its modulating model. The gap across the whole range is under two percentage points.
AFUE measures how much of the fuel becomes usable heat over a season. It does not measure how evenly that heat arrives. Two furnaces can post the same number and feel completely different to live with, which is where the series actually separate.
What does staging change day to day?
Staging controls how much heat the furnace makes at once. A single-stage furnace is either off or at full output. A two-stage furnace has a lower setting for most conditions. A modulating furnace adjusts across many small steps, which on the Infinity 59MN7 means 60 settings on the gas valve.
| Comfort | Performance | Infinity | |
|---|---|---|---|
| Burner staging | Single-stage | Two-stage, one single-stage model | Two-stage, and modulating with 60 settings |
| Blower | Multi 18-speed | Enhanced variable 25-speed | Variable-speed |
| AFUE listed | Up to 97% | Up to 97% | Up to 98.5% |
| Control | No communicating control listed | InteliSense Connected System with ecobee smart thermostat for Carrier | Infinity System Control, fully communicating |
| Humidity | Standard management | Dehumidification on thermostat call | Ideal Humidity Technology with a compatible outdoor unit |
| Best for | A well-sealed home where even heat is already easy | Most homes, most budgets | Drafty, exposed or multi-level homes, and anyone sensitive to temperature swings |
The practical effect of staging is run time. A furnace at a lower output runs longer to deliver the same heat, and a longer run moves air through the house for more of the hour. That is what flattens the difference between the room with the thermostat and the room over the garage.
Does the thermostat come with the furnace?
It depends on the series, and this is easy to miss when comparing quotes. The Infinity series is built around the Infinity System Control, a fully communicating control where furnace and thermostat exchange information. The Performance series uses the InteliSense Connected System with an ecobee smart thermostat for Carrier. Carrier lists no communicating control for Comfort.
Why communicating controls matter in practice
A conventional thermostat sends a simple call for heat. A communicating system lets the equipment report back, so staging and humidity decisions are made with more information. Carrier ties Ideal Humidity Technology to the Infinity control paired with a compatible outdoor unit, which is why humidity control is a system feature rather than a furnace feature.
What we see in Angus homes
Exposure changes the answer
Angus sits in Essa Township, where wind crosses open farmland with very little to break it. A house on an exposed lot loses heat faster on its windward side than a sheltered house in a built-up street, and it loses it unevenly. That is a staging problem rather than a capacity problem, and it is the clearest case for Performance or Infinity over Comfort.
The symptom is familiar: the thermostat says the house is at temperature while one end stays cold. A bigger single-stage furnace usually makes it worse, because it satisfies the thermostat faster and shuts off sooner.
Housing in Angus also splits by age. Newer subdivisions are tight and well sealed, so even heat comes easily and a Comfort series unit can be the sensible choice. Older homes and additions carry retrofitted ductwork, where the limit is often the duct and not the furnace. We check that before quoting a series, because a premium furnace on undersized return air disappoints at any efficiency rating.
Aire One Barrie serves Angus, Essa, Alliston, Thornton, Cookstown and the rest of Simcoe County. You can see the full Carrier line-up on the brands we carry page, or visit the Angus heating and cooling page.
Safety first
If a carbon monoxide alarm sounds: get everyone outside into fresh air, then call 911 from outside. Do not investigate the source yourself. Ontario's carbon monoxide alarm rules changed in January 2026 and most homes now need more alarms than they have.
If you smell a rotten egg or sulphur odour: leave the area immediately. From a safe distance, such as a neighbour's home, call the Enbridge Gas 24-hour emergency line at 1-866-763-5427 or 911.
Never open the furnace cabinet, touch gas lines, burners or the gas valve, bypass a safety switch, or handle refrigerant. Installing or replacing a furnace is work for a licensed technician.
How should you choose between them?
Work backwards from the complaint rather than forwards from the brochure. If the house already heats evenly and the only goal is replacing a tired furnace, Comfort does the job at nearly the same efficiency. If rooms disagree with each other, or the blower is loud, staging is what fixes that, and that means Performance or Infinity.
| If this is your situation | Start by pricing |
|---|---|
| Newer, well-sealed house; heat is already even | Comfort |
| Some rooms run cold; want a quieter blower | Performance |
| Exposed lot, drafty or multi-level; temperature swings bother you | Infinity |
| Winter humidity is a recurring problem | Infinity, with a compatible outdoor unit |
| Planning a heat pump later | Ask how the control pairs before choosing the furnace |
How Aire One answers this
Aire One has served Ontario since 1990 with licensed technicians, free detailed estimates that give you the price before work starts, 24/7 emergency service and a 100% satisfaction guarantee. Every quote follows an on-site assessment, because the ductwork and the sizing decide more than the series does. If you would rather spread the cost, there are rent or buy options.
The short version
Do not shop the Carrier furnace series on efficiency, because all three land near 97%. Shop them on staging, blower control and whether you want a communicating system. Then let the on-site assessment confirm the house can use what you are buying.
Talk to Aire One Barrie
Licensed technicians, free detailed estimates with the price before work starts, and 24/7 emergency service across Angus and Simcoe County. Furnaces, boilers, heat pumps, air conditioners, water heaters and indoor air quality.
- Carrier Factory Authorized Dealer — Comfort, Performance and Infinity series
- Rent or buy options on furnaces, air conditioners and water heaters
- 100% satisfaction guarantee
Frequently asked questions
Is the Carrier Infinity furnace more efficient than the Comfort furnace?
Barely, on paper. Carrier lists the Comfort series at up to 97% AFUE and the Performance series at up to 97%, while the Infinity series reaches up to 98.5% on its modulating model. The real difference between the series is not the efficiency rating. It is how finely the furnace can modulate its output and how well it holds a steady temperature.
What does a two-stage furnace actually do differently?
A single-stage furnace runs at full output or not at all. A two-stage furnace has a lower setting it uses most of the time, stepping up to full output only in deep cold. Because it runs longer at lower output, the air coming out is less blasty and the temperature swing between cycles is smaller.
Do I need the Infinity System Control to use an Infinity furnace?
The Infinity series is designed to communicate with the Infinity System Control, and features such as Ideal Humidity Technology depend on that pairing with a compatible outdoor unit. The Performance series uses a different approach, the InteliSense Connected System with an ecobee smart thermostat for Carrier.
Can I put a smart thermostat on a Comfort series furnace?
A standard smart thermostat will control it, because a single-stage furnace only needs an on and off signal. What you do not get is the two-way communication that lets a furnace and thermostat share staging and humidity information, since Carrier does not list a communicating control for the Comfort series.
Which Carrier furnace series is best for a drafty older house?
Usually a staged or modulating one, because the problem in a drafty house is uneven temperature rather than raw heating capacity. A single-stage furnace heats the thermostat's room quickly and shuts off, leaving the far rooms cold. A longer, gentler run cycle moves air for more of the hour. Sizing and ductwork still matter more than the badge, which is why an on-site assessment comes first.
Sources
- Carrier Canada — Residential gas furnaces: Infinity, Performance and Comfort series (specifications checked October 14, 2026)
- Technical Standards and Safety Authority — Find a registered fuels contractor
- Technical Standards and Safety Authority — Ontario Fire Code CO alarm requirements
- Enbridge Gas — Ontario emergency contact and gas leak instructions
