Short Answer: Does a portable air conditioner have to be vented to the outside?
No, a portable air conditioner does not have to be vented to the outside. Since portable ACs are like self-contained heat pumps, they collect heat from a room and send it somewhere else through an exhaust vent.
But portable ACs don’t need to vent out a window, as long as you can find another way to send the heat outside. For example, you can use an exhaust fan to draw warm air out of the room and push cool air into it.
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Detailed explanation – Does a portable air conditioner have to be vented to the outside?
Portable air conditioners are different from window units in that they’re smaller, more compact, and generally more energy-efficient. Most portable air conditioners can also be placed on a desk or bedside table rather than having to be installed in a window.
However, like larger air conditioners, portable models still require proper ventilation to remove moisture and extend the life of the unit. While most small central air units can vent directly to the outdoors, this is not always possible with portable units.
And because the exhaust from a portable unit is much closer to you than that of a central system, there are some additional precautions you will need to take if you cannot vent it to the outside.
How to Vent a Portable Air Conditioner
If your portable AC can be vented to the outside, you’ll want to do that. If you can’t, for whatever reason, you’ll need to select a different option for venting it indoors. The best way to figure out what’s best for you is to consult a contractor or HVAC specialist.
They can make sure you’re getting the best setup possible given your specific situation. For direct-exhaust portable AC units, you’ll need to find a way to direct the exhaust air outside. If you don’t have a window you can put it in, you might be able to get a wall- or ceiling-mounted exterior vent.
These look like regular HVAC vents and are designed to fit in with the other equipment outside your building.
Venting Alternatives
If your portable AC doesn’t have a direct-exhaust system, you can vent it in two different ways. The most common option is to install a wall or ceiling-mounted exhaust fan to draw the moist air out of the room.
You can choose from among several different types of exhaust fans, including a whole-house fan, a standard bathroom fan, or a car wash exhaust fan. If your portable AC doesn’t have a built-in condensate pump, you’ll also need to install a bucket or a pan to catch the water coming from the unit. You can also vent a portable AC through a window.
If you have an open window, you can just direct the air outside. If your window is closed, you can install a louvered shutter. Louvered shutters direct the air out of the room while still providing some privacy.
Installing a Shutter To Vent a Portable AC
If you’re vented through a closed window, the best option is a louvered shutter. Louvered shutters are specifically designed to vent air out of a closed window. They come in portable and fixed varieties and are easy to install.
First, you’ll need to find the right louvered shutter for the size of the window. Measure the width and depth of the window frame and take the height into account as well. If your window is taller than standard, you might need to engineer a larger shutter. Depending on the shutter, you’ll install it either directly on the window or on a wall above the window.
Follow the manufacturer’s installation instructions and make sure there’s a gap of about 1/4 inch at the bottom of the shutter. This allows the moist air escaping from the AC to be drawn outside.
Installing an Evaporator Drain
An evaporator drain is a bit like a sump pump for your AC. If you have a direct-exhaust AC, you can install the drain on the outside of the unit. If you have a portable AC without an exhaust, you can install the pump inside.
The drain runs continuously, drawing water out of the unit and into a floor drain or a bucket connected to the pump. Installing an evaporator drain is a bit more involved than installing a shutter, as you’ll also need to run a line to the drain. Your HVAC contractor can help you run the line so it’s out of the way and doesn’t get crushed by foot traffic or furniture.
Installing a Coils-Only Drain (CDC)
Like an evaporator drain, a coils-only drain runs continuously to catch the water from your AC. The difference is that with a coils-only drain, you don’t run a line to a drain. Instead, the water stays in the unit and is periodically emptied by the owner.
A coils-only drain is most often used with a portable AC. It’s a good option if you don’t want to install an evaporator drain. It’s also better for the environment since you’re reducing the amount of water that goes into the sewage system. If you have a coils-only drain on your portable AC, you’ll need to empty it periodically.
Most often, you’ll do this once a week or once every two weeks. Consult the owner’s manual for your unit to find out how often you need to do this.
You Don’t Have to Vents But…
If you don’t have a direct-exhaust portable AC, you can install a wall- or ceiling-mounted exhaust fan to vent the moist air out of the room. You’ll also need to install a bucket or a pan under the unit to catch the condensation. In these situations, you’ll also want to make sure you have a good ventilation system in place in your home.
Ideally, you’ll have a whole-house fan that pulls moist air out of the home and brings fresh air in. But if you don’t have a whole-house fan, you can install at least one in-wall exhaust fan to bring in the fresh air and remove the moist air.
Summary
Portable air conditioners are great for cooling down small spaces, including bedrooms, dens, and offices. While they may take up less floor space than a window unit, they still require proper ventilation to remove the water that is created as a byproduct of cooling.
When installing a portable AC, make sure that you are providing proper ventilation to the unit by choosing an exhaust option that best fits your needs. If you don’t have a direct-exhaust system, you can vent it in two different ways. The most common option is to install a wall or ceiling-mounted exhaust fan to draw the moist air out of the room.
You can also install a louvered shutter, evaporator drain, or coils-only drain to vent the moist air out of the room if your portable AC doesn’t have a direct-exhaust system.
What happens if you don’t vent a portable air conditioner?
Not venting a portable air conditioner is bad for two reasons. First, it means that the inside of the unit will become humid and potentially encourage mold to grow. Second, it means that the AC will cycle between dry, cool air and humid, hot air.
Since most AC units consume about 1,000 watts of electricity, this would actually heat up your room far more than it would cool off.
Can a portable air conditioner be vented inside?
A portable air conditioner can be vented inside if you install a compatible vent kit with the AC. A vent kit is a device that allows you to affix the AC to a wall or window, and then run a hose outside through an exterior wall so that the unit can draw fresh air into the room while it exhausts hot and humid air.
A well-designed kit makes installation as simple as possible, while also providing flexibility in installation options.
How far from the wall should a portable air conditioner be?
Every manufacturer has different recommendations, but the general rule of thumb is to have at least one foot (or 12 inches) of clearance on each side of your air conditioner.
Your air conditioner’s manufacturer may have specific clearance recommendations, but they’ll generally recommend between 12 and 24 inches.
