Large portable air conditioners typically start at 12,000 Btu, short for British Thermal Unit, which is a measurement of the unit's cooling capacity. This size is best for kitchens, rooms larger than 400 square feet, and smaller 300-square-foot rooms that get full sun. Don't be tempted to get a unit that's too large for your space: Experts say that an oversized unit will actually cool the room too quickly, causing it to turn off before it's had the chance to remove as much moisture from the air as possible. Some have extra functions, acting as a dehumidifier or heater. These appliances can be used year-round, reducing the need to roll them into storage at the end of the season.
The 12,000-Btu NewAir AC-12000E (Est. $460) gets some of the highest owner ratings for a large portable air conditioner. Most say it quickly cools a hot room between 300 and 425 square feet. The temperature can be set between 64 and 90 degrees Fahrenheit, with a programmable timer that customizes cooling for 24 hours. Its biggest drawback is the noise; at 57 decibels, the AC-12000E is the loudest air conditioner in our report. Many users say it's worth it for the excellent cooling performance. "This unit is a bit on the noisy side when the compressor kicks in, but it does the job wonderfully," says one owner at Air-n-Water.com.
Owner reviews say the EdgeStar Extreme Cool AP12000S (Est. $390) is one of the few large portable air conditioners that is reliable for several years. It's also an excellent value, featuring a 3M carbon filter, effective dehumidifier and programmable timer. "This unit looks great, is compact in size, and really cools well. I highly recommend it to anyone looking for a small size and powerful portable air conditioner," says one owner at retail website LivingDirect.com.
The EdgeStar Extreme Cool AP14001HS (Est. $500) is similar to the top-rated AP120008 but adds extra cooling power and a heater function. At 14,000 Btu, owners say it can keep large spaces cool, even on the hottest days. The Extreme Cool AP14001HS is the heaviest portable air conditioner in our report, weighing 75 pounds. This doesn't bother some owners -- because it functions as both an air conditioner and a heater, many owners leave it set up year-round.
The EdgeStar AP12000SA and AP14001HS are quieter than the NewAir AC-12000E, and include a three-year limited warranty (which is better than NewAir's one-year coverage). However, the NewAir is the lightest of the three and has higher owner ratings overall.
In the large portable air conditioner category, few other units have consistently high ratings from a significant number of owner reviews. Worth mentioning is the Whynter ARC-14S and the Soleus LX-140, two 14,000-Btu portable air conditioners with slightly lower scores than our top picks. The Whynter has a high energy rating (11.2 EER) and excellent dehumidifying power (removing 101 pints per day). But it can struggle to circulate air effectively, according to some. Similar to the EdgeStar AP14001HS, the Soleus doubles as both an air conditioner and a heater, with impressive performance for both. Reviews often complain about its poorly designed self-evaporation system and durability issues.