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Portable Air Conditioner Buying Guide (2025)

Portable Air Conditioner Buying Guide (2025)

Bedrooms, offices, garages, and server rooms are often warmer than desired because of a lack of proper ventilation or poor air circulation. This is precisely where portable air conditioners come in: They're small, portable cooling systems that quickly cool rooms without access to central AC. They're also great for spot cooling specific areas like your bedroom, apartment, or office. 

For easy accessibility to the topics in this guide, use our topic list:

About Portable Air Conditioners

Honeywell MN Series 10,000 BTU Portable Air ConditionerA portable air conditioner is used to provide supplemental cooling to specific areas in your home or business. They don't require permanent installation, but most require a window for ventilation or a separate space to direct the system's exhaust. Most models dehumidify as they cool, and most are also easily mobile.

Portable ACs differ by brand, maximum cooling area, venting configuration, energy efficiency, and special features–like multiple operating modes, remote control operation, programmable timers, and specialized air filters.

Size

While most portable air conditioners provide multiple BTU (British Thermal Unit) ratings, DOE Standard and Standards, understanding exactly what each one means can be a little tricky. In fact, the portable AC industry is going through a transition period when it comes to BTU ratings and our Introducing New Portable AC BTU Guidelines post walks you through the details.

An easier factor to look at when choosing a portable air conditioner is the room size it's intended for. An air conditioner that's too small won't keep up with the cooling demands of your environment, while one that's too large will cool the area and shut down before removing excess moisture from the area - leaving your space muggy. Use the info below to find an appropriate model for your space:

Note that you should increase the size and power of your portable AC if:

  • Your space has lots of windows or heat-generating appliances
  • You reside in a warm, humid state
  • You’re cooling a poorly insulated room, such as a garage or workshop
  • Your room has high ceilings

If you need help determining the right size for your needs, call our product experts at 1-800-934-9194 for a free consultation and an expert recommendation.

Ventilation and Exhaust

All portable air conditioners vent hot air as part of the cooling process. This hot air is typically vented out of the area being cooled using an exhaust hose and can be vented out of a window, drop ceiling, sliding glass door, or through a wall. Most portable ACs come with window kits or drop ceiling panel kits that include the needed exhaust hose and parts.

For more detailed information about ventilation, read our article How To Vent Your Portable AC.

Single or Double Exhaust Hose?

Honeywell MN Series Portable Air ConditionerPortable ACs can be single- or double-hosed for exhausting hot air and pulling air in to cool. Some models have both exhausting options. Here is a breakdown of both options:

  • Single-Hose Portable ACs: single-hose portable air conditioner works by drawing in air from the space, cooling it, and returning most of the air back into the room. A small amount of this air will be used to cool the appliance and will be blown out of the air conditioner's exhaust hose. This does create a slight negative air pressure since it uses air from inside the room cool down the compressor. 
  • Dual-Hose Portable ACs: A dual-hose portable air conditioner pulls in room air, cools it, and then releases it back into your space. Since the unit heats up during this process, one intake hose pulls in air from outside to cool down the unit. Then, this air is expelled through a second exhaust hose. As such, a dual-hose portable AC does not create negative pressure inside the room being cooled like single hose models, and it may be more efficient than a single-hose portable AC s since the AC doesn't have to work as hard during the cooling process. However, dual-hose units use warmer, unconditioned air to cool their compressors, which can result in slightly weakened efficiency. Also, depending on the design, a dual-hose portable air conditioner may use two internal fans, which may also result in slightly higher energy usage.

Draining Condensate

When a portable AC cools indoor air, it also acts like a dehumidifier and removes water from the air. Portable ACs have different ways of handling this moisture buildup:

  • Fully Self-Evaporative ACsSome models are self-evaporative, meaning the AC exhausts almost all condensate and you seldom have to drain the collected water. These are especially desirable when you want the freedom to leave them running unattended. When using in dry mode, or when the air is ultra-humid, some condensate may accumulate, but is easily drained.
  • Partially Self-Evaporative ACsUnits can evaporate a great deal of moisture into their hot air exhaust, and there is little or no water to empty. How often you’ll have to drain the water will depend on usage and environmental conditions.
  • Gravity Drain/Drain Hose: All portable air conditioners support the option of a permanent water drain hose connection. This allows collected water to continuously drain out to a nearby floor drain using the force of gravity–and also means you won’t have to drain the water manually.
  • Condensate Pumps: Condensate pumps are available as separate accessories to help pump the collected water through a drain hose. These pumps can move water in an upward direction to drain water up and out of an area (through a window, for example).
  • Buckets: The simplest portable air conditioners have an internal container that holds extra water and needs to be manually drained regularly.

Efficiency

Portable ACs tend to be energy efficient and can save you money on your monthly electric bill. Efficiency is measured by the portable AC’s Energy Efficiency Ratio (EER); generally speaking, the higher the EER, the more efficient the model. A rating of 10 is typically considered a very good rating for portable ACs.

Read our Lower Your Energy Bill with a Portable AC article for more about portable air conditioners and efficiency.

Electrical Outlet Requirements

Honeywell MN Series 12,000 BTU Dual Hose Portable Air ConditionerMost portable ACs use a typical household 120-volt power outlet and require no special wiring. However, some powerful portable ACs, such as commercial-grade units, may require special outlets. Read the product description and specifications to determine the power requirements when selecting a room air conditioner. 

Noise Level

Portable air conditioners make noise, because they use motorized fans and compressor systems that cool and circulate the air. Many people consider it “background noise,” others are concerned with appliance noise. If you’re concerned about noise in your room, we suggest buying a portable AC with special features that minimize the sound. Features to look for include a programmable timer, multiple speeds, and a Sleep mode.

Some portable air conditioners list the decibel rating of the system at each fan speed. You can compare these ratings to other indoor appliances, but remember sound is different to each individual. Many conditions can affect the sound level, such as the position of the unit, if you have carpeting, what type of furniture you have, and the fan speed.

For easy reference, use the comparison chart below to get an idea for the level of sound a portable air conditioner will make based on its decibel measurement.

How Loud is a Decibel Chart

Installation and Maintenance

Maintaining your portable air conditioner is simple and requires very little effort. Most systems work as a "set it and forget it" appliance. However, to get the most out of your investment, you should keep up on general maintenance to ensure it has a long lifespan.

Suggested maintenance includes:

  • Clean air filters as needed (usually once every summer).
  • Ensure it’s installed correctly for maximum efficiency.
  • Drain your portable air conditioner before storing it.
  • Check your warranty for more specific information on the parts and services covered.

Cooling Server and Computer Rooms

Additional cooling is needed in many server rooms, and portable ACs are often used as supplemental or primary cooling systems in these areas. 

When considering an AC, overestimate the amount of BTUs needed to cool the space; these areas get very hot with electric equipment running. Exhausting your AC is another consideration, because many server rooms don’t provide access to windows. Our customers usually direct the hot air exhaust hose into a drop ceiling or through a hole in the wall in these cases.

Check out our suggestions for computer/server room portable ACs.

Heating Options

Portable ACs that offer a Heat mode generate heat either through a heat pump or electric heater. Electric heat is suggested for cold, northern climates while heat pumps work best in moderate temperatures.

In winter months, a heat pump extracts heat from outside air and disperses it throughout the area. It can reverse its system to cool areas as well. Heat pumps tend to be more efficient than electric heaters because they simply transfer heat.

In contrast, units with electric heat convert electrical energy into heat using a heat strip in the unit. While this method uses more electrical power to heat than a heat pump, it also can handle colder environments.

Interested in a portable AC with heat? Check out our bestselling portable air conditioner heaters.

Special Features

Honeywell MO10CES 10,000 BTU Portable Air Conditioner w/ Front Grill Body DesignMany portable air conditioners offer special features that enhance your cooling experience. These features add convenience and save you money on energy costs. They include:

  • Self-evaporating technology
  • Directional air control
  • Remote control
  • Washable air filters
  • Casters for easy mobility
  • Programmable timer
  • Digital controls
  • Multiple fan speeds
  • Carrying handle
  • Additional modes: Dehumidify, Fan, Heat, Automatic, Energy-conserving

In Summary

Portable air conditioners are the perfect temporary cooling solution for bedrooms, offices, garages and other spaces without access to central air conditioning.

Still Have Questions?

For more information on specific portable air conditioners and other indoor air treatment solutions, review our extensive product listings and visit our Knowledge Center. Not sure what's best for you? We can take the guesswork out of decision-making. Contact our product experts toll free at 1-800-934-9194. We want to help you make your indoor environment a healthy one.

  • Alexander Popp

    Alexander Popp is the content manager at Sylvane, overseeing the creation of articles, blog posts, product information, and educational materials about air quality and comfort. Formerly an award-winning local journalist, Alexander is well-versed in delivering concise, accurate, and engaging product information to engaged customers.

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