Model
Century RXTS-101A
Rank #143 means 142 of the 404 room air conditioner models we track cost less to run each year; the 65th efficiency percentile means it uses less energy for its size than 65% of those models.
What does the Century RXTS-101A cost to run per year?
The Century RXTS-101A is a relatively cheap runner for its class: about $93 a year, rank #143 of 404. It uses 38% less energy than the U.S. federal standard model in its class, which would cost about $150/yr to run, a saving of roughly $57 a year. Its 65th size-adjusted efficiency percentile is a step ahead of the class median, though not among the very top results. Its CEER of 15 reflects combined energy efficiency ratio, one of the class's core efficiency levers.
Immediately around it on the leaderboard, the Black+Decker BD10NWES at $93/yr runs a little cheaper and the Comfort Aire RXTS-101A at $93/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 Century RXTS-101A's $93/yr adds up to roughly $930 in electricity alone, before purchase price or repairs.
Also sold as: Black+Decker BD10NWES.
By the numbers
The Century RXTS-101A 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 $93/yr, here is what the Century RXTS-101A adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Century RXTS-101A costs about $930. That is roughly $570 less than a standard model in its class, which would run closer to $1500 over the same ten years.
How the Century RXTS-101A compares
The room air conditioner class we track runs from $51 to $389 a year. At $93/yr, it runs about $6 a year cheaper than the class median of $99, and it is about $42 a year more than the cheapest room air conditioner to run at $51. Against the US federal standard model for its class at about $150/yr, the Century RXTS-101A uses 38% less energy.
What drives its running cost
At 10000 BTU/hr, the Century RXTS-101A 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. Beyond size, its CEER of 15, above the class median of 15, is the class's own efficiency yardstick, combined energy efficiency ratio, and it is what separates two similarly sized models with different running costs.
- Combined Energy Efficiency Ratio (CEER). CEER captures cooling output per watt, including standby power; a higher CEER means less electricity for the same BTU of cooling.
- BTU cooling capacity. A higher-BTU unit is sized for a bigger room and generally uses more electricity per hour of operation than a smaller unit, regardless of efficiency.
- Thermostat and mode usage. Running on a fixed low temperature around the clock uses far more energy than using a thermostat setting, eco mode, or a timer to match cooling to when the room is actually occupied.
Common questions
Is the Century RXTS-101A cheap to run?
Yes, relatively. At $93 a year it ranks #143 of 404 room air conditioner models we track, in the cheaper part of its class to run.
How much does the Century RXTS-101A cost per month?
Roughly $7.73/mo, spreading the $93/yr estimate evenly across twelve months at $0.1856/kWh. Actual monthly bills swing with your rate and usage pattern.
How is this running-cost figure calculated?
We take the model's published annual energy use of 500 kWh from ENERGY STAR and multiply it by the US average residential electricity rate of $0.1856/kWh, giving about $93 a year. It is an electricity-only estimate and does not include purchase price, water, or installation.
How efficient is the Century RXTS-101A for its size?
65th percentile once size is factored in, a fairly typical result for the class.
Cheaper to run in the same class
| Rank | Model | Cost/yr |
|---|---|---|
| 143 | Black+Decker BD10NWES10000 BTU/hr | $93 |
| 142 | Ge Profile AHTR10ACH210100 BTU/hr | $90 |
| 141 | Tcl W10WC72-B10000 BTU/hr | $87 |
| 140 | Tcl W10WC7210000 BTU/hr | $87 |
| 139 | Tcl T10WV9SB10000 BTU/hr | $87 |
Source
ES_0017771_RXTS-101A_09272024112716_80221244View certified room air conditioner listingsENERGY STAR data as of July 2026Century and RXTS-101A 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.