Brothers 102399

ENERGY STAR certifiedMeets ENERGY STAR Most Efficient criteria

Through-the-wall air conditioner · 10000 BTU/hr

InYour statethis room air conditioner costs

about $8 a month

$96 a year

An estimate at your state's average rate — not a guarantee of your bill.

Estimated yearly cost

$74

a year

The yellow sticker says $74 a year.

You'll pay $21 more.

Sticker uses 14¢ per kWh. The U.S. average is 18.0¢ per kWh.

Energy use

532 kWh a year

vs similar through-the-wall air conditioner

-14%

Cheaper room air conditioners, same size

ENERGY STAR lists 14 other certified models at the same 532 kWh a year, size and type, so everything on this page applies to them too.

Compare all 208 room air conditioners 8,000–12,000 BTU

Cost in every state

532 kWh a year × each state's average residential rate (EIA 12-month average through July 2026).

State	Rate	Per year	Per month
Hawaii	43.7¢	$232	about $19 a month
California	33.1¢	$176	about $15 a month
Massachusetts	30.4¢	$162	about $13 a month
Rhode Island	29.4¢	$156	about $13 a month
Maine	29.3¢	$156	about $13 a month
New York	28.4¢	$151	about $13 a month
Connecticut	28.2¢	$150	about $12 a month
Alaska	27.0¢	$144	about $12 a month
New Hampshire	26.8¢	$142	about $12 a month
District of Columbia	24.2¢	$129	about $11 a month

Show all 52 states

Vermont	23.9¢	$127	about $11 a month
New Jersey	23.6¢	$126	about $10 a month
Maryland	22.3¢	$119	about $10 a month
Michigan	21.0¢	$112	about $9 a month
Pennsylvania	20.8¢	$110	about $9 a month
Illinois	19.0¢	$101	about $8 a month
Wisconsin	18.8¢	$100	about $8 a month
Ohio	18.3¢	$97	about $8 a month
U.S. average	18.0¢	$96	about $8 a month
Delaware	18.0¢	$96	about $8 a month
Indiana	17.1¢	$91	about $8 a month
Virginia	16.6¢	$88	about $7 a month
Colorado	16.6¢	$88	about $7 a month
Alabama	16.5¢	$88	about $7 a month
Minnesota	16.2¢	$86	about $7 a month
Texas	16.0¢	$85	about $7 a month
South Carolina	15.7¢	$84	about $7 a month
West Virginia	15.7¢	$83	about $7 a month
Oregon	15.6¢	$83	about $7 a month
Arizona	15.5¢	$82	about $7 a month
Florida	15.4¢	$82	about $7 a month
New Mexico	15.2¢	$81	about $7 a month
Kansas	15.1¢	$80	about $7 a month
Georgia	15.1¢	$80	about $7 a month
Mississippi	14.9¢	$79	about $7 a month
North Carolina	14.9¢	$79	about $7 a month
South Dakota	14.3¢	$76	about $6 a month
Washington	14.2¢	$75	about $6 a month
Wyoming	14.2¢	$75	about $6 a month
Iowa	14.1¢	$75	about $6 a month
Kentucky	14.0¢	$74	about $6 a month
Montana	13.9¢	$74	about $6 a month
Missouri	13.9¢	$74	about $6 a month
Tennessee	13.7¢	$73	about $6 a month
Oklahoma	13.6¢	$72	about $6 a month
Nevada	13.6¢	$72	about $6 a month
Arkansas	13.5¢	$72	about $6 a month
Utah	13.3¢	$71	about $6 a month
Louisiana	13.1¢	$70	about $6 a month
Nebraska	12.9¢	$69	about $6 a month
Idaho	12.7¢	$67	about $6 a month
North Dakota	12.5¢	$67	about $6 a month

What the Brothers 102399 costs where electricity is expensive

At Hawaii's average residential rate of 43.7¢ per kWh, the Brothers 102399 costs $232 a year — $158 more a year than the label says. The EnergyGuide label estimates $74 a year, because every label in the country is calculated at 14¢ per kWh. At the U.S. average of 18.0¢ per kWh this room air conditioner costs $96 a year, and in North Dakota, the cheapest state, $67 a year.

Estimated annual running cost for the Brothers 102399 in the highest-rate states and the lowest-rate state
Where	Rate	Cost a year	vs the label
Hawaii	43.7¢ per kWh	$232	+$158
California	33.1¢ per kWh	$176	+$102
Massachusetts	30.4¢ per kWh	$162	+$87
Rhode Island	29.4¢ per kWh	$156	+$82
Maine	29.3¢ per kWh	$156	+$81
North Dakota	12.5¢ per kWh	$67	−$8

Electricity prices: EIA 12-month average through July 2026, residential sector, average revenue per kWh. Label figure calculated at 14¢ per kWh, the rate the FTC requires on labels.

Full specs

At the U.S. average residential rate this one costs $96 a year — about 14% cheaper to run than the average through-the-wall air conditioner ($111 a year across 53 certified models).

$96

Most efficient $77Average $111Least efficient $180

Every model on this scale is ENERGY STAR certified. Range across 53 through-the-wall air conditioners, priced a year at the U.S. average residential rate.

Brand: Brothers
Model number: 102399
Type: Through-the-wall air conditioner
Capacity: 10000 BTU/hr
Annual energy use: 532 kWh a year
Combined Energy Factor (CEF): 14.1
Better than the federal standard: 47% less energy
ENERGY STAR Most Efficient: Yes
On the market since: August 2026
Certified: August 2026
Cooling capacity (BTU/hr): 10000
CEER: 14.1
Mounting: Does Not Straddle Window or Windowsill
Variable-speed compressor: Yes
Heating mode: No
Voltage: 230
Width (in): 24.1
Height (in): 14.7
Depth (in): 20.9

Where to buy

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Common questions

+How much does the Brothers 102399 cost to run per month?

about $8 a month at the U.S. average residential rate of 18.0¢ per kWh, or $96 a year. Your cost depends on your state's rate — see the table above.

+How many kWh does the Brothers 102399 use?

532 kWh a year, as the manufacturer filed it with the EPA, in the ENERGY STAR certified product database.

+Is the Brothers 102399 energy efficient?

It is listed as ENERGY STAR certified, and it meets the ENERGY STAR Most Efficient criteria. It uses about 14% less electricity than the average through-the-wall air conditioner (average: 617 kWh a year).

+How does the Brothers 102399 compare to the average room air conditioner?

The average through-the-wall air conditioner in our database uses 617 kWh a year, costing $111 a year at the U.S. average residential rate. The Brothers 102399 uses 532 kWh a year, costing $96 a year.

How we calculate this

Annual energy use (532 kWh a year) is the figure the manufacturer filed for this model with the EPA, in the ENERGY STAR certified product database. Running cost is that figure multiplied by a state's average residential electricity price from the U.S. Energy Information Administration (12-month average through July 2026, average revenue per kWh).

The annual figure for a room air conditioner assumes 750 hours of cooling a year, per the DOE test procedure (10 CFR 430 Subpart B, Appendix F, §5.2.1). Full methodology.

Sources: EPA ENERGY STAR certified product data, updated weekly · U.S. EIA electricity prices, 12-month average through July 2026.