Best Portable Air Conditioner: Shop by SACC, Not the Box BTU

The portable we'd buy is the Whynter ARC-1230WNH, for a bedroom, office or studio whose window can't take a window unit. It matches the best rated cooling of any portable we cover, publishes its efficiency and a full noise table, heats with a heat pump in spring and fall, and carries the longest compressor term in the group. Its catch is the warranty: service is mail-in, and it only covers units bought from an authorized Whynter dealer.

Most people shopping for a portable should still check one thing first, and the rest depends on the room:

• Your window is single- or double-hung: buy a window unit instead. Midea's 10,000 BTU U-shaped unit matches the smaller Midea Duo's rating, is ENERGY STAR certified at CEER 15 and costs far less than either inverter portable. Our window air conditioner guide has the full field.
• Slider, casement or a lease that bans window units: the Whynter ARC-1230WNH, if your opening is at least 28 inches for its kit.
• Opening shorter than 28 inches, or you want the larger owner record: the Midea Duo, whose kit spans 19.1 to 63.8 inches. It ties the Whynter on rated cooling and certifies the same CEER with DOE.
• Lowest price, a few hot weeks a year: BLACK+DECKER's inverter BPACT08NM, not the best-selling BPACT10WT. The inverter model delivers more rated cooling for about 45% less electricity per BTU.
• A garage: read our garage portable guide first; a hot two-car garage can ask for more cooling than any portable is rated for.
• A humid climate: budget a drain hose or a condensate pump from day one.

Our scores, ranked

Scores are from our full reviews: Performance 40%, Reliability 35%, Value 25%. We've added the Midea U window unit for scale, because it's what we'd buy instead whenever the window allows it.

For portables, window units and through-the-wall units side by side, see every model ranked; the BTU column there is SACC for every portable.

No portable scores well with us, and that's deliberate. A portable keeps a compressor in the room, needs a hose and a window panel, takes floor space, and usually costs more than a window unit with the same DOE rating. The Whynter and the Duo earn their place because some rooms can't take a window unit. The BPACT10WT scores lowest because its efficiency sits right at the federal minimum for its size and owners report units that beep and switch themselves off at random.

Shop by SACC, not the box

Most portables carry two cooling numbers, and the listing leads with the bigger ASHRAE figure. The lower one is the SACC (seasonally adjusted cooling capacity) from the DOE's 2017 portable test, which accounts for heat the unit and its hose leak back into the room. Whynter's ARC-14S spec page names both standards. Here's how far apart they run:

Two portables with "14,000 BTU" on the box can sit 2,500 BTU apart in rated cooling, and the ARC-1280WX sold as the smaller 13,000 BTU unit out-rates the 14,000 BTU ARC-14S. Size by SACC. Fed its SACC, ENERGY STAR's room AC chart puts the BPACT10WT near a 250 square foot room, not the 450 its listing claims; the BPACT14WT's 10,200 lands at 400-450.

To compare with a window unit, hold the portable's SACC against the window unit's DOE rating: a 10,000 BTU SACC portable against a 10,000 BTU window unit. The two test procedures aren't identical, so treat it as the closest match available. Never hold a portable's 14,000 against a window unit's 12,000 and conclude the portable is bigger.

When a window unit wins, and when it can't

If the window takes one, a window unit wins on almost every count. It keeps the compressor outside, drains outdoors, takes no floor space, can carry ENERGY STAR (portables are excluded from the room AC specification) and usually costs less. The Midea U adds a closed sash between the room and the compressor, which no portable can match for noise.

Efficiency is closer than the usual line suggests, if you buy an inverter portable. Energy use for the same cooling scales with 1 divided by CEER. Run 12,000 BTU an hour of cooling for 1,000 hours and you've moved 12 million BTU:

Window and portable CEERs come from different DOE test procedures, so the comparison is approximate. The point stands: the best inverter portables are close to a window unit on paper, and a fixed-speed portable isn't.

A portable is the right call when the window can't take a window unit: a horizontal slider, a casement, an opening too narrow or too short, or a lease, HOA or building that bans anything hanging outside the glass. Our window AC vs portable AC guide goes through those cases. If you own the place and want heat and cooling for years, a ductless mini-split is the long-term answer; see mini-split vs window AC.

Single hose, dual hose and hose-in-hose

A single-hose portable cools its condenser with room air you already paid to cool, then blows that air outdoors. Every cubic foot that leaves is replaced by hot, humid air from the hallway, the attic hatch and the window gaps. That's why single-hose units struggle to dry a muggy apartment. Some owners are happy with theirs. In an old, leaky building in a humid climate, we'd skip them.

A dual-hose unit pulls outdoor air across the condenser and sends it back out, so it doesn't depressurize the room. Hose-in-hose (the Whynter ARC-1230WNH and the Midea Duo) runs both through one oversized duct and one window opening. It's a tidier install, but the duct is stiff, so the unit has to sit close to and in front of the window.

The efficiency gap is large. At its rated SACC, the BPACT10WT draws about 955 watts per hour of full cooling (6,300 ÷ 6.6). Black+Decker's own inverter single-hose BPACT08NM delivers 8,000 BTU SACC at CEER 12.0, about 667 watts, roughly 45% less electricity per BTU for more cooling. The dual-hose inverters at CEER 14.2 use about half the electricity of the BPACT12WT's 7.3 for the same rated cooling. If you run a portable every night all summer, buy an inverter.

If you do end up with a single hose, keep it short and straight, seal the window kit with its foam, and wrap the hose in an insulated sleeve so it stops radiating heat back into the room.

Plan the water before it arrives

Most portables are built to throw cooling condensate onto the hot condenser coil and blow it out with the exhaust. In dry or mild climates that works, and Duo owners in places like Michigan, Iowa and the Pacific Northwest go whole summers without draining. In humid weather the pan outruns the evaporation and the unit stops with a full-tank code: P1 on the Duo and the ARC-1230WNH, "ft" on the BPACT.

The built-in pumps on the Whynter and the Duo heat models only run in heat mode, per both makers' manuals, so in summer you either run a drain hose downhill to a floor drain or container, or set a small condensate pump below the drain port and run its line out the window. If your summers are humid, set that up on day one.

Mold is the other water problem. Seven or more Duo owners describe mold or a mildew smell, mostly on the blower wheel, which is hard to reach without splitting the case. Midea's manual says to drain the tray and run the unit in fan mode for 12 hours before storage; we'd also run fan-only for a while after each cooling session.

Heat mode has a floor

Both hose-in-hose picks heat with a heat pump, not a resistance coil, which makes them useful in spring and fall. The Midea Duo's manual rates heat-pump operation at 41 to 86°F outdoors, and it shuts off at 41°F and below. Whynter rates the ARC-1230WNH at 12,000 BTU of heat but publishes no low-temperature limit we could read, so ask Whynter before counting on it once nights drop into the 40s. Both need the drain hose whenever they heat.

Neither is winter heat for a cold climate. For a room you'll heat all winter, a cold-climate mini-split is the answer.

Warranty and what service looks like

Service on a heavy appliance is where portables hurt. Read the terms before you choose between the two inverter picks:

When we checked in October 2026, the Whynter listing we link was sold by a third-party seller, and the Duo heat model had no featured offer, only a third-party seller listing it new. Confirm who's selling it, and buy where the return window is easy, because the first month is when a bad unit shows itself.

Which portable we would buy

• Slider, casement or no-window-unit rule, nightly use: the Whynter ARC-1230WNH.
• Opening under 28 inches, or a dry climate: the Midea Duo; the MAP12S1TBL for a typical bedroom, the heat model if you want spring and fall heat.
• A few hot weeks a year on a budget: the BLACK+DECKER BPACT08NM inverter.
• Any single- or double-hung window it fits: a Midea U window unit instead.
• A garage: start with our garage portable guide; a 115V mini-split is often the better buy there.

We'd skip the BPACT10WT unless the price gap to the inverter model matters more than a bill nearly twice as high per hour of cooling. If you buy one anyway, size it for about 250 square feet and keep the return window open for the shutoff fault.