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This is an acronym for Clean Air Delivery Rate, an AHAM (Association of Home Appliance Manufacturers) certification for air purifiers. How well an air purifier works depends on the percentage of pollutants removed as air goes through the filter system combined with the amount of air that goes through the unit. In other words, you want a unit that cleans a lot of air extremely well.

To help consumers evaluate air purifiers, AHAM devised a test that evaluates the combined effectiveness of filtration and capacity. The test results are expressed in Clean Air Delivery Rate or CADR. This is the test that the American Lung Association and the EPA look to as a standardized test for evaluating the performance of air purifiers.

What the CADR tells you is the amount of 100% clean air in cubic feet per minute that is coming out of an air purifier. There are three tests and therefore three numbers provided, one for smoke, one for pollen and one for dust. In addition, specific room sizes that an air purifier is rated for are part of the CADR listing.

The maximum value for smoke and pollen is 450 and for dust is 400. When selecting an air purifier, the closer the CADR is to these maximums the better.

Cable Winder

See "Cord Winder"

Canister Type Vacuum Cleaner

The simplest way to understand the difference between a canister and an upright vacuum cleaner is that you pull a canister and push an upright. A canister vacuum cleaner has a base unit that contains the vacuum motor, dust bag and filter system.

There are three types of canister vacuum cleaners. All three are used with a hose and attachments. The difference is in the attachments. A canister that has no power nozzle of any kind is called a Straight Suction Canister. It is suitable for environments with no or very little carpet.

The second type is a canister with a turbo or turbine power nozzle, which is a power nozzle with a revolving brush that is powered by the airflow created by the canister's suction motor. This type of canister is a good choice when soiling conditions are moderate or the amount of carpet and rugs in the home is minimal.

The third type of canister features a power nozzle where a separate electric motor drives the brush roll. This type of canister is often referred to as a Power Team and is ideal for homes with large amounts of carpet or rugs and standard to heavy soiling conditions.

Centrifugal Fan

A fan or blower that has a fan wheel with a number of fan blades mounted around a hub like a paddle wheel. The air enters from the side of the fan wheel and then turns 90 degrees, accelerating as it passes over the fan blades. This fan gets its name from the trajectory of the airflow as it exits the fan housing. A common example of a centrifugal fan is the blower used in forced air heating and cooling systems.

Clean-Air Design

This is a vacuum cleaner design where the airflow that carries the dirt passes through most of the filtering system before it reaches the motor where it passes through the fans (and may also be used to cool the motor). With this design there is usually an additional filter installed after the motor to filter any carbon dust produced by the motor itself. This type of design increases motor longevity, produces excellent suction and eliminates fan breakage and motor damage common in "dirty air" traditional upright vacuums.

Cleaning Effectiveness

Cleaning effectiveness is how well a vacuum cleaner removes unwanted contaminants such as soils, pet hair, dust, allergens, etc. from the environment. There are two components to cleaning effectiveness. The first is the removal of the soil from carpet, flooring or above the floor surfaces. The second is successfully capturing these soils in the dust bag or container, returning the minimum amount of contaminants back into the environment in the exhaust air.

Cold Evaporation

See "Cool Mist".

Compressor, Reciprocating

A type of compressor used in dehumidifiers and air conditioners that compresses the refrigerant by use of a piston and cylinder design.

Compressor, Rotary

A type of heavy-duty compressor used in commercial grade dehumidifiers that compresses refrigerant by use of a rotary screw design.

Cool Mist

This is a method of humidification that uses a variety of methods to release moisture into room air without heating the water. Cool mist humidifiers include evaporative, impeller and ultrasonic types.

Cord Reel

See "Cord Winder"

Cord Retractor

See "Cord Winder"

Cord Release

On vacuum cleaners that do not have cord rewinders, the power cord is generally wrapped around cord holders that come in a variety of design configurations. A Quick Cord Release is a design that releases all the wrapped cord with a single adjustment so the user does not have to unwrap each turn of cord from the holders. This is a convenient and time saving feature. Sometimes referred to as a "Quick Cord Release".

Cord Winder

A feature on vacuum cleaners and other appliances that retracts the cord onto a reel or spool inside the vacuum cleaner. Typically activated by the touch of a button there are also cord winders that retract automatically during cleaning. Also referred to as a "Cord Retractor", "Cord Reel", "Cable Winder", etc.

Cubic Feet Per Minute

Also referred to as "CFM" this is a unit of measure used to calculate airflow. See "Airflow".

Cyclonic Action

A method of vacuum cleaner filtration that separates soils from the airflow by making the air stream spin, subjecting it to centrifugal force, which throws the dirt and debris out of the air. Cyclonic filtration is used in a variety of "bagless" type vacuum cleaners. Dyson has developed an advanced cyclonic filtration system that represents the state-of-the-art in this technology.

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