When buying a portable air conditioner there are many factors that you need to make in your decision like manual or digital controls with a remote, air purifiers, 2 or 3 speed fan setting, heating option.
Here are most top 5 things to consider before you buy a portable air conditioner:
1.    What size portable air conditioner do I need?
When buy an air conditioner regardless of it’s a Portable, window, split or central air system, the production of the unit is based on room size your planning on  cooling
Is the room(s) you are trying to cool able to be closed off with a door or not. Example if you are planning on  cooling your living room is the living room connected to the dinning room or parlor etc etc. If your space is an open concept without the ability to close off the room from the rest of the house, you will have to add the other rooms in the room sizing  chart.
All air conditioners, including portable air conditioners, are rated in British Thermal Units (BTUs). Larger units with higher BTU ratings offer more cooling power.
Area to Be Cooled in
(Square Feet)
Capacity Needed in (BTUs per Hour)
250SqFt    10,000 BTU
300SqFt   11,000 BTU
350SqFt   12,000 BTU
400SqFt   13.000 BTU
450SqFt   14,000 BTU

Note that the above guidelines are not exact. Some factors may increase or decrease the number of BTUs required. For example, if you live in a hot, humid state like Florida; if your ceilings are taller than 8 feet; if the room contains several heat-producing appliances; or if you’re trying to cool a poorly insulated room, such as a garage, then you’ll need to increase the BTUs accordingly.
Also, keep in mind that BTU ratings for portable air conditioners are not exactly the same as BTU ratings for traditional window air conditioners. In general, portable air conditioners cover about half the area as window air conditioners with the same BTU rating. Therefore, if you’re replacing an old window unit with a new PAC, you should double the BTU rating of the window unit.
2.    Location of the portable air conditioner

Location, location, location.  All portable air conditioners, when running, produce hot air that must be exhausted out a single, double hung or sliding window.  The portable air conditioner must be located within a max of 4- 6ft range depending on the length of the manufactures  exhaust hose.  Sorry a portable air conditioner will not work in a casement window. We do not recommend you exhaust the hot air into crawl space, attic, or plenum. A portable air conditioner will not work with 2 exhaust hoses connected together. The exhaust hose’s motor is not strong enough and it will lose efficiency
3.      Size of the portable air conditioner
While all portable air conditioners are “portable /mobile” some models are bigger and bulkier than others so you have to ask yourself do you plan on moving it from one room to the next or up or down a flight a stairs some models weight 80 + lbs and can be a bit cumbersome to move around.
4.        Water removal / maintenance of your portable air conditioner
Most Portable Air Conditioners  a require little maintenance: they come with a washable filter which is designed to keep the internal parts or A/c clean ( not for air purification ) you are going to want to clean that once or twice a season, A/c with air purifiers will need more upkeep w/ changing the hepa filters  every 1-3 months based on the manufactures suggestions ad or the local environment.
Water removal
Air conditioners do two things, they condition the room (cooler temperature) and they dry moisture out of the air which is called condensate.  Portable air conditioners collect the water and remove it 1-3 ways.
1.        Older models (which are still on the market) collect the water in a tank and you manually drain the water every 2-6 hours depending on the size of the tank, and the humidity in the air
2.        Self Evaporation technology:  the technology recycles the water condensation to cool off the cooling coils, then evaporates the water out with the exhaust air. This results in increased energy efficiency, cooling performance and reduces the need to empty the water tank. Under extreme humid conditions, the water condensation may collect faster than the unit can recycle. Should the built-in water tank becomes full, the compressor will automatically shut-off and water full indicator will blink. At this time, water should be emptied, which is a simple process.
3.        Condensate Pump:  water is collected in a tank or pan in the bottom of the unit and is pumped out a small hose out the window.
5: noise level

The last one was a toss up between noise level and controls. We have found more customers said the level of noise was satisfactory in the purchase decision. While noise level is subject, because the items in the room will dull or amplify the noise of the unit, for example a carpet floor verse a wood floor will reduce some of the noise. When looking for noise level on specs they are listed in Db’s or  decibel the 40’s is the noise level in a working library and the high 50’s and 60’s is the noise level you would hear at the dinner table.  When looking at units noise level make sure you see if the rating is base on a high or low can speed.