Ventless Portable Air Conditioner: Pros and Cons post image

Ventless Portable Air Conditioner: Pros and Cons

With summer just around the corner, many of you might be looking to beat the heat by investing in an air cooling solution. In the absence of an optimal air cooling appliance, high temperatures can ruin the environment, creating uncomfortable and unbearable spaces, both at home and in the office. If you live in a place that gets hot, investing in an air cooling system is both important and a necessity.

Air conditioners come in different types. As each type differs from the other in terms of specifications and features, it is crucial that you have a clear understanding about the different air cooling options available to you. Also, when selecting a unit, it is important that you match the unit with your requirements.

For instance, a portable air conditioner is a compact air cooling solution that can be easily moved from place to place. As compared to central or window air conditioning systems, portable air conditioners do not require permanent installation. Instead, these units can be installed by yourself in a fraction of an hour, and without the help of any expert. Thus, if you were looking for a mobile, temporary air cooling unit, the portable air conditioner would be the right choice.

Similarly, if you were in need of a compact unit that did not require an outside ventilation,ย the ventless portable air conditioner would be your best choice.ย 

What are ventless portable air conditioners?

A ventless portable air conditioner is also known as a swamp cooler or an evaporative air conditioner.

Although called an air conditioner, technically,ย  it is not!

Why? Because in order to be categorized as an air conditioner (which treats, chills, dehumidifies and filters the air), a unit must have an outside vent connection to dissipate the heat.This is not the case with ventless portable air conditioners.

These units have more resemblance (mechanically) to a large swamp cooler, with the additional benefit of having the capacity to cool large spaces.

Why ventless?ย 

The unit is ventless because it does not need to exhaust any heat outside.ย  Unlike central, window and split air conditioner units, ventless portable systems neither use a refrigerant not a compressor for its cooling mechanism, in the absence of which, the system generates no heat.

How do ventless portable units work?

Before examining the mechanism of a ventless unit, let’s first take a look at the mechanism of a typical air conditioner.

All air conditioners (central, window and portable) follow the principle of heat transfer. These units absorb warm air from the room, cool it by means of a refrigerant and circulate the cooled air back into the room. Simultaneously, the heat built within the system is released outside through a vent connected to the wall, window or any similar opening. Through this continuous process of cooling and heat removal, the temperature in the room is brought to the desired level.ย  It should be emphasisedย that the efficiency of the portable air conditioner depends on how effectively the unit is vented.ย 

On the other hand, ventless portable systems work based on an evaporation-cooling mechanism. Instead of absorbing and cooling warm air from the room, these units cool the room by evaporating water stored in its system. Let’s examine this further.

Parts of a ventless portable system

In order to understand the mechanism, let’s first take a look at the parts of the unit. Every ventless portable system has a:

  • Water tank or reservoir at the bottom of the unit. The reservoir prevents the unit from tipping over by lowering its center of gravity.
  • Fan and pump, which pulls the water from the tank
  • Cooling pad or wet filter pads, on which the water is dripped. These are located on either sides of the unit.

Mechanism of the ventless portable system

  • Water collected in the reservoir is evaporated.
  • Simultaneously, air from the room is pulled into the unit and pushed towards the cooling pad.
  • As the air moves across the cooling, it is saturated with moisture.
  • The cooled air is then blasted back into the room via fans.

Evaporation-Cooling Mechanism. Source:

To simplify the process, one can say that the air is cooled by adding moisture to it.ย It is for this reason that ventless portable units have large tanks (14-42 pint capacity), to allow for continuous cooling of the room.

Selecting a ventless portable air conditioner

Here are some factors to consider when choosing a ventless portable unit for your home:

  1. Cooling capacity: Each unit will have a description of its cooling capacity, a measure of the maximum area that can be cooled by the unit. In order to select an optimal unit, you will first have to determine the area of the room intended for cooling and match it to the capacity of the unit.
  2. Features: Most latest models are equipped with high end features such as auto-restart, remote control operated, digital display and a programmable timer. Choose a unit with all the convenience features that you require.
  3. Portable: While these units are portable, consider that some of them might be heavy. This is a crucial factor to consider, especially if you have to carry your unit up and down the stairs to your apartment or room.ย  The height of the unit also must be considered to enable easy transport by car. When moving the unit around, ensure there is a socket nearby for the unit to be plugged it. Avoid using extension cords as it might cause overheating of the wires.
  4. Water tank: To avoid having to continously refill the water tank, select models with bigger tank capacity (around 7 gallons of water).
  5. Noise level: Choose models with the least noise range possible, generally around 50dBA or below.

Installation of ventless portable air conditioners

Most portable air conditioning units come with an easy to install window venting kit. However, with ventless portable air conditioners, you do not have to install any window venting kit. Instead, installation ofย  the unit requires only three simple steps:

  1. Plug in the unit
  2. Add or ensure that there is sufficient water in the water tank for the unit to use.
  3. Switch on and allow the unit to cool the room. The unit can cool the room faster if all the doors and windows are kept closed.

However, as the same air is being re-circulated into the room, it would be better to place the unit near a window or door, where there is a regular supply of fresh air, to prevent over-saturating the inside air.

Pros and cons of a ventless portable air conditioner

Like with every other appliance, there are pros and cons to using a ventless portable unit. Let’s take a look at them:


1. A ventless portable system is mobile: This is highly advantageous if you are looking for a unit that can be used in more than one room. Most of the units are equipped with caster wheels to aid easy transferring.

2. Easy to install: When compared to central or window air conditioning systems, ventless portable units do not require permanent installation. You, also do not need to be a professional to install this unit in your room.

3. Ventless: Ventless portable units are most optimal for spacesย that do not have a suitable opening for a venting kit.ย If you are planning to install an air cooling system in your room and you do not want to break your wall, ceiling or floor, then you should consider a ventless system. This is why, ventless portable units are great for spaces likeย warehouses and garages.

4. Easy to maintain: Maintenance of a ventless portable air cooling system is much simpler as compared to its counterparts. For this unit, all you have to do is regularly clean the water tank and the filters (if they are removable and washable). Servicing the unit is also cheaper as compared to the other air conditioner systems and can be easily done with your basic tools.

5. Cost effective: Ventless portable units are much cheaper that central, window and even poratble air conditioners. On an average a small portable ventless unit costs around $40. The cost of the unit depends on the size you require, and amount of duct work(for larger units). To determine the size of the unit, use the following equation:

(Square footage of home * height of ceiling/ 2).ย 

6. Low energy consumption: The cost of running an air conditioning unit mainly depends on the capacity of the system, hours of operations, and power rating. If you have a unit that consumes a lot of power, then it may cause your electricity bill to shoot up. Ventless portable systems consume only around 90-160 watts electricity an hour as opposed to other systems that consume over 500 watts per hour. Ventless units help you save on your electricity bills.

7. Low operation costs: The monthly average cost to operate the unit is around $20, which is the bare minimum required to cool a room. Operation costs depends on the:

  • Size of the unit and area of room
  • Humidity of the space
  • Local utility rate
  • Efficiency of the unit.

8. Environment friendly: Ventless portable units are more environment friendly as they emit no harmful gas and use no refrigerants.


On the downside, a ventless portable air conditioner has :

1. Lower efficiency:ย As compared to a window air conditioning unit, a portable system delivers lower efficiency. Nevertheless, you can maximize the efficiency of your unit by ensuring that it is properly installed and regularly serviced.

2. Slower action: It takes more time to cool a space. These units are also not suitable for larger spaces.

3. Ventilation problem: The unit has ventilation issues because it keeps on circulating the same air in your room. It is important to consider how you will be ensuring that the air in your room is fresh before purchasing this unit.

4. High humidity: Most importantly, ventless portable units are unsuited for areas with high humidity.ย  In areas with dry climate, the unit is able to saturate the air with moisture, causing a cooling effect. But in humid areas, as the air is already moisture-laden, the air cannot taken in more moisture, reducing the cooling effect of the unit. A ventless portable unit is therefore most effective in dry and less humid areas.

Thus this unitย is not a suitable choice, if you are looking for a unit with:

  • High cooling efficiency:
  • Fast cooling action
  • Fresh air supply

Despite these disadvantages,ย  the ventless portable system is definitely your best choice if you are looking for an air cooling solution that is budget-friendly, portable, easy to use, effective, energy efficient and require no venting through an opening in your space.

FYI: The Air Geeks' top-rated portable AC units tested in 2020:
1. Black+Decker โ€“ BPACT14WT: the all-around best option (very large rooms)
2. Whynter - Elite Arc 122DS: the best value (large rooms)
3. Honeywell - MN10CSWW: superior unit, great price (avg. rooms)
4. Honeywell โ€“ MO08CESWK: a very good entry-level option (small rooms)