Can you Run a Portable Air Conditioner Without an Exhaust Hose?

It is often surprising to find a large exhaust vent hose in the air conditioner package when it arrives, as they are rarely advertised in the photos. No matter if you’re looking for a portable or if you’re using the same old air conditioner, we’ll help you understand whether you really need the exhaust hose or not.

To keep things short, although you do not need the vent hose in the dehumidifier mode, which will produce heat, but you will need it otherwise.

Can you Run a Portable Air Conditioner Without an Exhaust Hose?


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How do portable air conditioners function?

It absorbs the moisture and heat from your air and expels it outside.

Most air conditions have a refrigerant that absorbs heat through the evaporator coil when it’s in vapor form, and then once it is in liquid form transfers it through a condenser coil. The two-step process is common in appliances which are used to cool things down. Freezers and refrigerators are examples.

To produce cold air, the air which comes through the air conditioner from outside goes through the cold evaporator coil. This coil removes the heat from the air and condenses its humidity into water droplets. This is how nearly all air conditioners cool air.

For heating, however, there are variations depending on the equipment. If you have a central system, there will be a giant condenser coil on the exterior of the home or building with a fan, which brings in heat to the air. This system makes a lot of noise due to the compressor and condenser, so we recommend keeping those parts of the machine outside.

If you use a portable air conditioner, the machinery used to heat up the air will stay indoors. To conserve the heat, you do not need an exhaust hose. To cool down your room, you will need a vent hose.

Is it okay not to use a vent?

When cooling, the portable air conditioner is very similar to a purpose-built dehumidifier. The main difference is that portable air conditioner uses a hot condenser coil to drop its absorbed water on, which makes the hot water removal process a lot easier as it limits the amount of times you have to manually take out the water. By expelling the air and humidity outside you save even more time and energy.

By taking off the vent hose, the air will not properly circulate and will just cycle between cool and dry to hot and humid. If you want to cool your room, not using a vent will actually heat it up more than it will cool it.

If there is too much humidity produced a dehumidifier would be helpful. That said, if you want to keep your room cool, it is always a good idea to keep the exhaust hose attached to the air conditioner.

True Air Conditioners

A portable air conditioner uses a cooling mechanism with a refrigerant to pull warm air through. The refrigerant absorbs warm air and expels out outside through the ventilation. It is by expelling the air outside that the room stays cool, and to warm the room the air is kept inside.

For an air conditioner to correctly work, it is important to have a ventilation hose system which can expel air outside.

To save on space, make sure your portable air conditioner is set up near a window, that way, you will only need a short vent hose. If it is not possible to bring it near one or if you have worries for safety, the vent hose can sometimes be installed through a wall, or the ceiling, and connected to the outside. This can be used for windowless rooms as well.

Ventless Air Conditioners

There also exist some ventless air conditioners you can buy. These are not really air conditioners. They are more commonly called swamp coolers and evaporative coolers. In this case the evaporative cooler has a tank which needs to be filled for the fan to push air out of the membrane. In more common air conditioners, the mechanism absorbs humidity out of the air, and fills a tank which must be dumped out only after being used.

The mechanism is one similar to perspiration: sweat is what cools your body as it seeps out of and evaporates from your skin. The heat is expelled from the air as the air goes through a wet membrane and the water is evaporated. This makes the air leaving the evaporator colder than the air absorbed.

These air coolers do not need a vent or a kind of water hose to function. They are ideal for buyers who need a cooling system that do not use hoses, but make sure to use them in areas of low-humidity.

A low-humidity area is one with less than 60% of humidity in the air. This will make your evaporative cooler function properly. In low-humidity areas these save on energy in comparison to air conditioners. That said, if there is more than 60% humidity, it will not properly function.

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