Does it bring in fresh air? No, air conditioners do not bring in fresh air from the outside. That's not how they were designed. What actually happens is that your air conditioner uses a fan to draw air into the unit and disperse it through a structure.
If you use portable air conditioners, the number of hoses will dictate whether they're safe to use in smoky conditions. Models with a single hose can pull smoke inside, meaning you should avoid operating them in these environments. If yours is a two-hosed model, check for a secure seal between the window and vent kit.
In most cases, your HVAC system does not pull air from outside when it is heating or cooling your home. Instead, it recirculates the air inside your home. This means it takes the air from inside your house, heats or cools it, and then sends it back into the rooms.
Short answer: your central air conditioner does not bring fresh air from outside your home. It recirculates the air that's already inside your home and cools it down. Here's an inside look at how central air conditioners work. A fan pulls warm air from your home into your unit.
In order to exhaust heat / hot air to the outside, the one hose unit must draw air from the inside of the room; and in doing so, additional air is drawn in from outside of the room. Unlike a central AC or window unit that draws air from outside to cool the condensing coils, these units are entirely inside the dwelling.
A window AC features ventilation grates on the side. These may seem positioned to draw in outside air. However, they only allow air into the condenser coil to help cool the machine so it doesn't overheat. Meanwhile, hot air is exhausted through the rear vents.
Vent through a door: If there are no windows available for venting, you may be able to vent the air conditioner through a door. Simply cut a small hole in the door and install a vent cover. Vent into another room: If there's another room nearby with a window, you may be able to vent the air conditioner into that room.
You can use an air conditioner without a window if you have another way to vent out the hot air.
Most modern window air conditioners create condensation which drips down to the pan on the bottom of the unit. There are no drain holes or plugs used to remove the water as was the case with older style window AC units. When the water builds up it is distributed by the fan sling and thrown up against the condenser.
The primary benefit of a window fan is that it can be used to pull in cool, fresh air from the outside or, it can be used to exhaust stale indoor air.
As long as the weather outside isn't excessively hot or humid, keeping your AC switched off while you sleep is a great way to reduce your energy costs. In fact, even in the nighttime temperatures are still in the 80s, this is still a good option as long as it isn't too humid outside.
The biggest determinant in how long you should run your AC is whether your home uses central air or a wall/window unit. In general, wall and window air conditioning units with smaller capacities can typically run for up to eight hours at a time before they need to rest.
Instead of 'creating' energy like conventional heating and cooling systems, reverse cycle air conditioners absorb outdoor air and use refrigerant gas to cool or heat the air, before pumping it inside. This is a much more energy-efficient climate control technique.
The AC Smells like Cigarette Smoke
When someone smokes in your home while the AC is running, the odor can accumulate on the filter and evaporator coil.
Does it bring in fresh air? No, air conditioners do not bring in fresh air from the outside. That's not how they were designed. What actually happens is that your air conditioner uses a fan to draw air into the unit and disperse it through a structure.
A window AC that is shaded can run at 30% less electricity to cool down a space, compared to a unit that is placed in direct sunlight. Place your unit where the air flow can move about freely. In other words, don't install your unit behind a piece of furniture or place anything directly in front of it.
Without proper ventilation, the hot air will accumulate, hindering the cooling process and reducing the efficiency of the air conditioner.
Experts generally recommend keeping your air vents open to ensure optimal performance of your HVAC system.
Portable Air Conditioners
Portable air units are stand-alone systems perfect for cooling individual rooms. The keyword here is “portable.” They can be moved from one place to another and often have an exhaust hose that expels the hot air outdoors. Still, they don't pull in outdoor air for cooling purposes.
Sliding the dampers manually into a closed position. Turning off a fan switch if the intake is fan-operated. Using the HVAC control panel to automatically close the damper. Turning the lever or knob on an outdoor or indoor unit that says “fresh” or “air intake”.
Portable air conditioners extract hot air from the room, and if you want to effectively cool your space, this hot air needs to be released outside. While portable ACs can be vented through a door, wall, or ceiling, they are most frequently vented through windows.
The energy consumption is massive, and you can expect bills to skyrocket. They're weak: A good portion of the energy consumed goes into the exhaust system of a portable unit, which reduces its ability to cool. That means on a hot Florida day, you're not even getting as much cooling as you need.