No, an air conditioner does not bring fresh air from outside to the inside of your home. While part of your system may be located outside, if you have a split system, this does not mean it uses the outside air. The primary purpose of your system is not cooling the air; it's to move the unwanted heat out of your air.
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.
It's a common belief that window ACs bring fresh air into your home from the outside. We're here to tell you—that's not true. Instead, a window air conditioner normally pulls air into it via a fan, cools and filters it, and then recirculates that air back into the building.
Not all air conditioners are safe to use when it is smoky outside, such as during a bushfire. Some air conditioners can draw in smoky air from outside, which can be harmful to your health. It's important to understand the type of air conditioner you have so that you know if, and how, to use it when it's smoky outside.
Locate Your Fresh Air Intake
The air intake is typically an open duct that leads to a vent on a wall outside your home or the attic. There's a small filter inside the vent so it can deliver clean air. This also lessens the demand for other HVAC filters. Depending on your home, it may have multiple fresh air intakes.
Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Outdoor air enters and leaves a house by: natural ventilation, such as through open windows and doors.
There is no pipe to bring outside air in for combustion. Instead, the boiler or furnace draws air from inside the home.
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.
While air conditioners excel in cooling and circulating air, it's important to distinguish between air circulation and air filtration. The primary goal of an air conditioning unit is to regulate temperature, not to purify air.
The fan from the indoor unit pulls hot air from inside the house through return air ducts. This heat from the air passes through filters where dust, lint and other airborne particles are collected. The filtered, warm indoor air then passes over cold evaporator coil.
As the refrigerant evaporates, it absorbs heat from the air passing over the coils. This cooled air is then circulated back into your home through a system of fans and ductwork. So while your AC unit does take in some amount of outdoor air, the vast majority of the air it's circulating is already inside your home.
Does your system pull in fresh, outside air and cool it down, or does it recirculate the air that's already inside? 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.
Whole house fans pull outdoor air into a home through open windows and exhaust it through vents in the attic and roof. This air circulation, in cubic feet per minute (CFM) provides cooling both in the house and the attic.
Never run an HVAC system without a filter. You can either turn the system off or run it sparingly until you replace the filter.
Tip: If you're looking to replace your outside AC unit filter, the filter location varies depending on the unit. However, it can usually be found along the air conditioner return duct.
So if your new home smells like tobacco, it was likely caused by the previous occupant. If you have ruled out thirdhand smoke as the culprit, electrical faults may be the cause. When insulation on wiring gets too hot, it can emit an acrid smell that some people mistake for cigarette odour.
Air Conditioner Cold Dry Air Contacting Warm Air
It is the humidity of the warm air suddenly becoming condensed by contact with the warm air, causing water droplets that are seen as smoke or fog. A common cause for this is that your air conditioner is not getting sufficient airflow through the system.
Air conditioners typically do not bring in fresh air from outside. The primary function of an air conditioner is to recirculate and cool the air that is already inside a building or space. Normally, no. The inside heat exchanger circulates air from the room back to the room.
Do All HVAC Systems Have a Fresh Air Intake? Most modern HVAC systems have fresh air intake capacity, but some are more limited than others. For example, your HVAC system might have one fresh air vent while other, newer models have many.
Air return vents, also known as return air grilles or cold air return vents, return the conditioned air via the return air ducts to the furnace, air handler, or packaged system. This starts the heating and cooling cycle over again. These vents do not have air blowing out.
No, an air conditioner does not bring fresh air from outside to the inside of your home. While part of your system may be located outside, if you have a split system, this does not mean it uses the outside air. The primary purpose of your system is not cooling the air; it's to move the unwanted heat out of your air.
To close a fresh air intake and cut off outdoor air, you first need to locate the intake, which is usually placed in the attic but may also be ducted to the central air handler's return side. Close an intake vent by sliding the dampers into the closed position.
A direct-vent sealed-combustion furnace, boiler, or water heater brings combustion air directly from outdoors to the sealed combustion chamber through one sealed pipe and exhausts the byproducts of combustion (carbon dioxide and nitrogen) to the outdoors through a second sealed pipe (Figure 1).