In order to effectively cool a space, an air conditioner must be installed the right way and that includes venting to exhaust hot, moisture laden air to the outside as they cool the inside. Let’s talk about what the vent is for on air conditioners and why you need to have one, especially on portable units.

All AC produces hot air as part of the refrigeration process in operation under the hood, which is the part of the process you don’t usually see or for many, even know about. Believe it or not, while making it nice and cool indoors, your AC is actually producing more hot air than cold.

So if you were wondering why air conditioners vent to the outside, hopefully this explanation will satisfy your curiosity and set you straight. Can’t beat learning some new knowledge about something that interests you each day!

Exhausting Hot Air Outside

It might be obvious, but if your goal is to cool a hot room down, you really don’t want any more hot air pumped into that room, only cold air, right? So the hot air is simply pumped outside and your room gets nice and cool.

This hot air is typically exhausted outside through fixed vents or ducting for whole house central AC, mini-split units or HVAC systems. With portable units, there is no fixed duct work, so instead, they utilize a flexible, detachable hose attached to an included window kit.

This is perfect where there is a convenient window in a room, but outside the ideal world model, traditional windows are not always available for this purpose. A standard window kit will generally include an adjustable window bracket (to fit different sizes of window opening), one or two vent hoses (depending on whether the AC unit is a single or dual hose model) and the exhaust vent hose adapters.

The average plastic vent hose will extend as much as 4 to 5 feet, although this will mean you will need to install your AC unit fairly close to a window for the hose to reach. Now for a little more on keeping cool with a portable air conditioner.

Some Issues when Installing an AC Hose

People often ask if they need to remove their window screen when installing a portable AC. Usually, you will not need to remove the screen unless it is in the way or inhibiting the air flow in some way.

If you’re thinking to replace a window kit designed for your model, it’s best to get a replacement from the AC’s manufacturer. Chances are you’ll easily find one that fits your needs from most hardware stores.

Connecting to Dryer Vents

In most cases, it is not recommended to use a dryer vent in order to exhaust a portable AC. Dryer vents typically have a 4-inch diameter whereas most AC exhaust hoses are slightly larger.

If the dryer vent’s external opening contains a flap, the AC unit’s hot air exhaust will generally not be strong enough to force it open. If this is the case, you should remove the flap and then replace it with a screen.

If you wanted to get warm in winter, I can tell you all about using heat pumps to save energy and money. But this post is about keeping cool in summer and being sensible about AC.

All in all, the end result you want to achieve is a cooler room. You do that by getting rid of the heat in there and using an AC to provide cool air and pump out the hot air is the solution.