Best portable air conditioners

Why buy a portable AC, what to look for?

If you don’t want the hassle of a window air conditioner, the best portable air conditioners can be a great alternative. But be aware that they are not rated by ENERGY STAR, efficiency ratings are typically lower than window air conditioners, and they are not truly portable in the way you might expect.

Let’s start with the basics of how portable air conditioners work.

Types of portable air conditioners

There are two types of portable air conditioners:

Condenser-based portable air conditioners such as the one pictured at left operate like a window air conditioner, with a refrigeration cycle that cools indoor air and exhausts the heat to the outside, usually through a window vent that attaches to any window. Condenser-based portable air conditioners remove moisture from the air as well, as dry air feels cooler than moist air. These air conditioners are typically not as efficient as window air conditioners – the one at left has an Energy Efficiency Ratio (EER) of 8.0, while a decent window air conditioner can achieve an EER of 10.7 or higher (the minimum allowed EER for a window air conditioner is 9.7).

The most efficient portable air conditioners are evaporative portable air conditioners such as the one pictured right. They use evaporation to cool the air. They draw outside air over water, causing some of the water to evaporate. Since evaporation is a cooling process, the moist air coming out of the air conditioner is cooler (and a bit more humid) than the dry air coming in from outside.

Evaporative portable air conditioners are ideal for very dry hot weather such as in the US southwest, Australia, or the dry season in tropical countries. They are 2-3 times more efficient than condenser-based portable air conditioners, but only in dry weather. You really don’t want to use one of these if you’re trying to cool a room in very humid weather; it won’t cool much, and it will make the humidity worse.

Evaporative air conditioners tend to be much cheaper than condenser-based portable air conditioners because there is no refrigerant or condenser pump. Many are available for under $200, just make sure an evaporative unit makes sense for your local humidity level. There are no EER ratings for evaporative air conditioners.

I won’t cover evaporative air conditioners below this section. Here are a few units you might want to look more closely at:

• BALKO Evaporative Air Cooler, 3-IN-1 – 6 pints + includes 4 ice packs – $140
• TEMEIKE Swamp Cooler – 8 pints – oscillating – $120
• Uthfy Evaporative Air Cooler – super high capcity at 80 pints and 3530 Cubic Feet per minute of air – $379
• Honeywell 300 CFM Indoor Portable Evaporative Cooler – 21 pints capacity – $160

Convenience of portable air conditioners

In terms of convenience, the best portable air conditioners are ones that are easy to set up, easy to to move around, and give you the option of not having to empty the water container. Condenser-based air conditioners pull humidity out of the indoor air, which condenses on the cooler’s condenser coils. Most units try to blow some or all of that condensed moisture out the window exhaust vent to the outside, but this evaporation takes additional energy so reduces the efficiency of the unit.

Look for a unit that has a tank to capture the water (the one at left has a 0.8L tank, which is small but still something), and switches to exhaust mode when the tank is full. This way, when you remember to empty the tank yourself, you’re saving more energy, and when you don’t, you at least have the convenience of not worrying about it shutting off when the tank fills up.

You can definitely save by buying the most efficient portable air conditioner and using it to provide cool air wherever you are. In just a few minutes you can unhook the unit from one window and hook it up to another, so you can keep your bedroom cool at night, your home office cool during the day, your kitchen cool in the evening. Most of them come with wheels to make them easy to move around.

Another convenient feature of the best portable air conditioners is the ability to heat as well as cool. Those with condenser-based refrigeration cycles can run the cycle backwards, which extracts heat from the cool outside air and pumps it indoors. Heat pump units are more efficient than electric heaters, as long as temperatures are above about 50F or 10C. (More recent vintage dedicated heat pump systems can achieve better performance than electric heaters at temperatures as low as 25F-30F or about -3C, but I would not expect portable air conditioners that also operate as heat pumps to achieve efficient operation at those low temperatures.)

Notice that I said “in just a few minutes” above. I don’t want to oversell the convenience of portable air conditioners. Most such units come with a window kit that fits at the base of a sash window – essentially, a rectangle that can stretch to different widths in order to accommodate different window widths, with a hole in the center that you use to attach the exhaust hose. It’s certainly more convenient to remove the kit from one window, move the kit, hose, and portable air conditioner to another sash window, and place the kit in the other window, than it is to drag a regular window air conditioner from one window to another. But if you don’t have sash windows, you’re out of luck, you can’t use these on casement windows. And if you were thinking you could just drag the unit itself from room to room, it is a little more involved than that. (Mind you, you can’t use window air conditioners on sash windows either.)

Efficiency of portable air conditioners

The best portable air conditioners have a Combined Energy Efficiency Ratio (CEER) above 7. Although portable air conditioners do not seem to be covered by either US or Canadian energy efficiency standards, the wide range of CEER ratings (on those units where they publish the CEER rating) shows that many manufacturers are just slapping together components and building something that “works” but that will (A) cost you a lot more to operate and (B) likely be running more for a given level of cooling than a truly energy efficient model.

I surveyed over 100 portable air conditioner units available on Amazon to establish CEER ratings, BTU, whether they provide heat as an additional option, and price. About 80% of the units do not publish efficiency information; I would stay away from these units. Any unit whose energy efficiency is high will be sure to publish its CEER rating. Another 10% had CEER ratings of 5.8 to 6.4 – again, I would stay away from these, as this is the low end of the efficiency range and you always want to go higher than the minimum. A handful of units provided heating (via heat pump) as well as cooling; these units are a good investment if you have a room that gets cold in winter and having a window open (or a hole cut through the wall) for the air exchange is a viable option. (For example, a casement window doesn’t work!) The best portable air conditioners I found are Whynter brand – they are pricier but their efficiency is over double the efficiency of the least efficient units who list a CEER rating, at a whopping 12.3 CEER.

Another thing to watch out for when shopping for a portable AC unit is bogus efficiency claims. A couple of obvious ones: Under the “ENERGY STAR” category in some product listings, the answer should be either Yes or No (although, as there is not an ENERGY STAR certification for portable air conditioners, this should always say No. I found several products who listed “5 star” under ENERGY STAR, which is flat out dishonest. There is no such thing as a 5-star ENERGY STAR designation. Avoid products where the listing shows dishonesty!

The best portable air conditioners have two hoses, one to draw air into the house and one to exhaust heated air out. The indoor air is drawn across the evaporator coils, while outdoor air is used to draw heat away from the condenser. However many units have only a single hose to vent exhaust heat. This means the units are effectively drawing already cooled, dehumidified indoor air out of the room and pumping it outside, thus reducing the efficiency of the unit.

Unfortunately, for lower BTU portable air conditioners in the 8,000 to 9,800 BTU range, it is hard to find anything over CEER 6.6. For units 10,000 BTU and over, the higher efficiency units (up to 12.3 CEER!) will quickly pay back the extra money you spend on sticker price.

Here is a table showing 9 of my top picks in terms of different BTU ratings, whether or not they provide heating as well as cooling, and CEER efficiency ratings. I’ve included one low efficiency unit, the Black+Decker, not because I recommend it but to contrast it to the others. For example, at current prices, it is over $250 cheaper than the same-capacity (14,000 BTU) units from Whynter, but you will pay for that up front savings at the electricity meter.

Product name	BTU/hour	Heat as well as cool?	CEER rating	Current price on Amazon.com
Whynter ARC-1230WN	14000	N	12.3	649
Whynter ARC-1230WNH	14000	Y	12.3	688
Whynter ARC-1030WN	12000	N	12.3	550
Portable Air Conditioner (no brand name)	10000	N	6.7	270
Pro Breeze 4 in 1 Portable Air Conditioner	10000	N	6.6	380
Pasapair WiFi Portable Air Conditioner	10000	N	6.6	240
FIOGOHUMI Portable Air Conditioner	10000	N	6.5	210
LEMBERI Portble Air Conditioner	8000	N	6.6	200
R.W.FLAME Portable Air Conditioner	8000	N	6.2	260
Black+Decker Portable Air Conditioner	10000	N	6.7	386
Black+Decker Portable Air Conditioner	14000	Y	5.8	415

All of the above seven air conditioners get good customer reviews and combine high efficiency with decent convenience. I especially recommend those that can heat as well as cool, as heat pump heating is usually more energy efficient than heating with gas, oil, or electricity when temperatures are cool but above freezing. Finally you can see, as you might suspect from my previous comments, a lot of Whynter portable air conditioners in the list above – I recommend Whynter as a brand, because they have a good reputation for quality and we should reward them for having the best overall energy efficiency of their portable air conditioner product line, among all manufacturers.