Portable Air Conditioners

For those on a tight budget that want to combat the heat of summer, portable air conditioners provide cool air without paying for a house-wide install which can be expensive.

Deciding on the right model for size and output is the only real issue here which is made easier thanks to helpful information provided in articles like this one!

portable air conditioning unitThere are many advantages as well as disadvantyages to opting for a portable cooling solution for your home. Here we look at them and explain in simple terms the things you need to know about them.

Advantages of Portable AC

The most obvious advantage of buying and using a portable, free standing air cooling model is the freedom of movement allowed by its design.

These units are generally light enough to move around the place on their easy-glide wheels making it easy to use in the room you are occupying and then moving to the next room you decide to go to so you can stay cool wherever you happen to be in the house.

There is an economical advantage here in that one small unit will use less power than a house-wide system if left on to cool the whole house including unoccupied rooms. It enables you to only cool the room(s) that you occupy while you are occupying it (them) and therefore only use the power needed to keep the space around you cool for comfort.

Disadvantages of Portable AC

While portability and economy are big plus points for these portable appliances, there are some minus points too. The biggest of these for most users is the need to vent the hot exhaust air the units produce to the outside of the house. I'll explain this:

All AC devices work by utilizing a refrigeration process to chill the air in a similar way your domestic refrigerator works to keep its contents cold.

If you ever stood behind your fridge, you probably noticed it was pretty hot near the base at the back by the compressor / motor, since they do produce a lot of heat. The same goes for the process going on inside your air conditioning, whether it's a fixed unit or a portable.

The difference is that AC needs to keep a much larger volume of air cool than a fridge, so it produces a much greater volume of hot air as it does cool air. This must be extracted from the room being cooled, or you'd actually end up with a net temperature increase!


Fixed AC units do this by venting through a port in an external wall of the house to an outside extraction unit with fans that pump the hot air out into the air outside.

Portable units don't have an external extraction unit to hook up to. So they have a flexible ridged hose that you need to either hang out a window or connect to a ready-made vent in an external wall.

The disadvantage of this arrangement is you either need a ready-made vent in each room you intend using the unit, or you need to place the unit near a window and hang the exhaust hose out an opening, blocking as much of the rest of that opening as possible. This is generally done with a window kit that comes with the AC unit or you can make one with a narrow polystyrene strip to fit the window opening above the vent hose.

A big downside to this aside from the messing around each time you move the unit to a different room is the security issue where a window needs to be kept slightly open, even at night. Many people are unhappy with this issue, with the only way around it being to either have a custom made window fitting to allow the hose to pass through without compromising the security of a closed and locked window.

This may not be such a big problem for some people as the positive side of at least being able to stay cool affordably. In that case, let's look at keeping running costs as low as possible:

Economical Operation

While the smaller, free standing air conditioning unit is more affordable to purchase, it can still use a lot of energy unless it's used wisely. So let's look at how to get the most from a portable AC device without it costing too much in energy consumption.

The biggest drain on energy used to heat or cool a building is in its lack of insulation and/or closing gaps that allow outside air to get in or inside air to get out. Making sure all window and door frames are properly sealed with caulk is a good first step to take.

There are self-evaporating portable air conditioners that are more efficient in operation than the regular AC units. This is because they re-use the condensate produced by the refriferation process to help cool the coils, saving energy and increasing the cooling capacity.

Another variation in portable AC configuration is the dual hose portable air conditioner which increases efficiency and thus reduces energy use by taking in outside air with one hose and exhausting hot air with the other.

While these units do cost a little more than regular portable AC units, they save money in the long run in operation costs.

Home Insulation

An insulated attic is another big difference maker when it comes to keeping heat or coolness inside the home and not leaking to the outside. Heavy curtains on windows or having double-glazed windows is another useful way to keep that costly artificial heat or coolness inside.

Another way to cut costs is to turn down the thermostat on the AC unit so you're not forcing it to drop the temperature more than you actually need it. It is surprisingly common for AC users to set the thermostat several degrees colder than is even comfortable so they can sit around in sweaters while the outside temperature is soaring in the sun!

Think about what is a comfortable temperature indoors and set the unit to keep it there. If you're not sure, just think what you set the heating level to in winter and use that temperature as your average!

Cooling Alternatives to AC

You may be surprised to learn there are actually some workable alternatives to spending money on running an AC unit, whether fixed or portable depending on where you live.

If your home can be shaded from the sun during the day, its internal temperature can be reduced significantly without any form of artificial climate control at all.

A large tree can do the job very well if you have the space for it, although not everyone wants they home towered over by a monstrous oak or maple! You can install temporary shading in the form of blinds and awnings top keep the sun off the walls and windows and just this can create a reduction of several degrees indoors.

Painting the external walls a light color, such as white will cause the sun's rays to be reflected with much less heat being absorbed by the walls and transferred to the interior. Installing an attic fan to cycle air through the attic space and out to the outside can prevent it heating up while also carrying some of the home's internal heat away too.

Evaporative Coolers

In areas of low humidity, a swamp cooler (evaporative cooler) arrangement can also reduce the temperature indoors without using a load of power. Small evaporative units can run on under 200 watts and produce as much cooling output as a comparable AC running at 10-20 times the energy consumption!

A swamp cooler is often referred to as a ventless portable air conditioner. These units are not refrigerant-based, so evaporative coolers do not produce any hot air to be vented.

This alternative is discussed in a separate article covering evaporative coolers and how they can be used effectively to keep temperatures down during the hottest days of the year in areas that have low humidity.

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