Model
Comfort Aire RXTS-81A
Rank #51 means 50 of the 404 room air conditioner models we track cost less to run each year; the 85th efficiency percentile means it uses less energy for its size than 85% of those models.
What does the Comfort Aire RXTS-81A cost to run per year?
The Comfort Aire RXTS-81A holds rank #51 of 404 on running cost, at about $74 a year, a genuinely cheap result for the class. It uses 38% less energy than the U.S. federal standard model in its class, which would cost about $120/yr to run, a saving of roughly $46 a year. Few room air conditioner models we track beat it on size-adjusted efficiency; it edges out 85% of the class once capacity is normalized. Its CEER of 15 reflects combined energy efficiency ratio, one of the class's core efficiency levers.
Immediately around it on the leaderboard, the Century RXTS-81A at $74/yr runs a little cheaper and the Danby DAC080B7IWDB-6 at $74/yr runs a little more, a sense of how tightly models are packed at this point in the ranking. A room air conditioner typically stays in service for somewhere around 10 years; over that span, the Comfort Aire RXTS-81A's $74/yr adds up to roughly $740 in electricity alone, before purchase price or repairs.
Also sold as: Black+Decker BD08NWES.
By the numbers
The Comfort Aire RXTS-81A normalized against its whole class, so each figure means something.
What it costs you over time
Running cost is an every-year number, so it compounds. At $74/yr, here is what the Comfort Aire RXTS-81A adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Comfort Aire RXTS-81A costs about $740. That is roughly $460 less than a standard model in its class, which would run closer to $1200 over the same ten years.
How the Comfort Aire RXTS-81A compares
The room air conditioner class we track runs from $51 to $389 a year. At $74/yr, it runs about $25 a year cheaper than the class median of $99, and it is about $23 a year more than the cheapest room air conditioner to run at $51. Against the US federal standard model for its class at about $120/yr, the Comfort Aire RXTS-81A uses 38% less energy.
What drives its running cost
At 8000 BTU/hr, the Comfort Aire RXTS-81A is a small room air conditioner for its class, which spans 5000 to 34100 BTU/hr with a median of 10100 BTU/hr, and smaller room air conditioner models generally cost less to run for the same job, all else being equal. The CEER of 15 on this model, above the class median of 15, measures combined energy efficiency ratio; it is the number to compare directly against another model's CEER if capacity is similar.
- Combined Energy Efficiency Ratio (CEER). Two units with the same BTU rating can post very different running costs, and CEER is the figure that explains most of that gap.
- BTU cooling capacity. BTU rating scales with room size, and it is usually the first driver of an air conditioner's running cost, ahead of its CEER figure.
- Thermostat and mode usage. How the unit is actually operated, thermostat cycling versus a fixed setting, moves real electricity use more than the rated BTU or CEER figure alone.
Common questions
Is the Comfort Aire RXTS-81A cheap to run?
Yes. Its $74/yr running cost puts it at rank #51 of 404, below what most room air conditioner models we track cost to run.
How much does the Comfort Aire RXTS-81A cost per month?
About $6.19 a month, which is the $74 annual estimate spread across twelve months at the US average rate of $0.1856/kWh. Your own bill scales with your local electricity rate and how heavily you use it.
How is this running-cost figure calculated?
The formula is annual kWh times price per kWh: 400 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $74 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Comfort Aire RXTS-81A for its size?
85th percentile once size is factored in. That means its size-adjusted efficiency is a real factor in the running-cost figure above; its capacity plays a large role too.
Cheaper to run in the same class
Source
ES_0017771_RXTS-81A_07272023175325_80167537View certified room air conditioner listingsENERGY STAR data as of July 2026Comfort Aire and RXTS-81A are used here for identification only and are not endorsements. Figures are computed by WattWise Labs from public ENERGY STAR data, not measured in our own lab.