Model
Della 048-TL-W10KI
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 Della 048-TL-W10KI cost to run per year?
At about $93 a year, the Della 048-TL-W10KI undercuts most room air conditioner models we track on running cost, 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. Efficiency-wise, once size is accounted for, it edges out 65% of the class, a modestly above-average showing. Its CEER of 15 reflects combined energy efficiency ratio, one of the class's core efficiency levers.
Immediately around it on the leaderboard, the Danby DAC100B8IWDB-6 at $93/yr runs a little cheaper and the Element EHWR10BE 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 Della 048-TL-W10KI'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 Della 048-TL-W10KI 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 Della 048-TL-W10KI adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Della 048-TL-W10KI 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 Della 048-TL-W10KI 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 Della 048-TL-W10KI uses 38% less energy.
What drives its running cost
At 10000 BTU/hr, the Della 048-TL-W10KI is a small room air conditioner for its class, which spans 5000 to 34100 BTU/hr with a median of 10100 BTU/hr, less capacity to service is usually the first reason a running-cost figure lands on the low side, before efficiency even enters the picture. 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). 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 Della 048-TL-W10KI cheap to run?
Yes. Its $93/yr running cost puts it at rank #143 of 404, below what most room air conditioner models we track cost to run.
How much does the Della 048-TL-W10KI cost per month?
About $7.73 a month, which is the $93 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: 500 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $93 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Della 048-TL-W10KI for its size?
65th percentile once size is factored in, a fairly typical result for the class.
Cheaper to run in the same class
Source
ES_1141693_048-TL-W10KI_02292024172105_3444940View certified room air conditioner listingsENERGY STAR data as of July 2026Della and 048-TL-W10KI 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.