What’s the Difference Between Ventilation and Air Filtration?
Image provided by QleanAir Scandinavia.
This is a common question when people start thinking about the air quality in their homes. Both are important contributors to indoor air quality, but each plays a different role in making your air more healthy and comfortable.
Here's a look at the differences between the two fields, and how they work together in your home.
What is ventilation?
By definition, ventilation is the distribution of fresh air to a room or building. Just about all homes and public buildings have and need ventilation. Stagnating air can be dangerous to breathe, because of the accumulation of airborne contaminants, so ventilation was designed to supply the outdoor air into a building. Needless to say, ventilation to a building is vital. The common issue with ventilation systems though is the quality of airflow, as well as filtration. Some ventilation systems do not filter the particles, or, filter only certain types of particles, i.e. larger, less dangerous particles.
There are several types of ventilation systems: natural, mechanical and hybrid or "mixed–mode", and all with different degrees of airflow. Generally, public spaces (offices, schools, healthcare facilities, hotels etc.) often will experience clogged and dirty ventilation systems; or antiquated systems due to the age and/or construction of the building.
Simply put, ventilation is there to provide a good IAQ (indoor air quality). Normally this is measured in CO2/VOC (Volatile Organic Compound) concentration, oxygen level, temperature, humidity, etc. within the building, or facility. Where ventilation face challenges are when there is an “extreme” production of contaminants in terms of particles or gases that it is not scaled for; or where the outside air quality suddenly is much worse than before. An air cleaner is then a good support to the ventilation system to reduce the contaminants in the room, thereby lowering the need for increased ventilation as the oxygen, temperature, humidity and CO2 levels are correct. One benefit is the cost savings for the client, as less energy is needed for the HVAC system for fans, heating/cooling etc.
Latest studies being released
Several studies throughout the world researching the effects of air quality in schools are now publishing their collected data. The evidence points to insufficient ventilation and poor indoor air quality as definitive causes of health issues and declined academic performance of students. There are also corroborating evidence effects as well, regarding the performance and health of people working in indoor environments.
What is air filtration?
Air filtration captures air particles at the source through specialized filters, i.e., HEPA and/or carbon gas filters; and releases clean air back into the environment. One main distinction between filters and ventilation is that air filtration doesn't bring in the needed fresh air (oxygen) to a building; ventilation does that. Another difference is that there are various types of filters used for capturing different types and sizes of air particles.
The most dangerous air particles are usually not efficiently trapped through common ventilations' filters, compared to a specialized air filtration system/unit.
Evidence of this can be seen in dirty air ducts. The EPA (Environmental Protection Agency) has published material stating; "Pollutants that enter the home both from outdoors and indoor activities such as cooking, cleaning, smoking, or just moving around can cause greater exposure to contaminants than dirty air ducts." (Click here for the original source).
An air filtration unit is an ideal accompaniment to a ventilation system if you want an indoor environment's air to be cleaner; not onlybecause it can trap air contamination without releasing it back into the environment, but because some systems can also assist in a smart air flow. Some air filtration units are also designed to trap toxic gases, like cooking fumes and passive cigarette smoke; including second, and third-hand smoke.
Common issues and solutions for poor ventilation
Besides outdoor pollution and contaminants entering inside through ventilation, windows, doors and people; air quality can become dangerous from building dampness. The spread of mold and bacteria can also lead to acute respiratory infections and/or disease.
Businesses, hospitals, and schools may be situated in an older building; – a building with either an antiquated ventilation system or made of toxic materials that elicit symptoms of sick building syndrome in people. If they are renting their locale, most likely the commune or private owner may bring out a ventilation specialist to examine a complaint, but the cost for remodeling a whole ventilation system, plus the inconvenience from downtime and interruptions from construction may leave most businesses thinking it's not worth the aggravation and continue to suffer from the effects of poor indoor air quality. The most economical and fastest solution to solve this issue is to install an air filtration unit, or units depending on how large of an area needs to be cleaned. They help with adding a more powerful and controllable airflow, and most importantly, clean the air from impurities and contaminants.
There are commercial air filtration units ideal for homes as well as industrial ones perfect for businesses and establishments of all industries, but it's best to have a ventilation or air quality specialist come and measure your air quality before blindly purchasing a solution.
A little more in-depth
So which is better; higher air–flow, or higher air filtration rate? The answer is not so simple and depends on what type of room or facility, as well the occupants and actions performed in such space to get the best effect in the indoor environment.
An example would be, an air filter that has an E11 filter offers better airflow, because it's more porous and captures larger air contaminants, compared to an H14 filter in the same unit that captures smaller particles, but the resistance means a slower air flow. There's no right or wrong. It's what's better for the specific environment that counts.
How much space does an air filtration unit take?
While some industrial air cleaners are robust in size, many are discreet and mobile. There are ones that are floor models that may be relocated as well as more permanent, ceiling models that are well disguised and don't draw attention.
Read more about indoor air quality.