You’ve been yearning for a refresher on fresher air and healthy living, and you realized that you could achieve all of this simply by purifying the air! Air purifiers are as different as world cuisines and use different methods to achieve the same goal. Some are extremely confusing to operate, some have additional functions you won’t be able to understand, so we’re here to help you sort things out. We’ve provided a glossary of terms you can use to evaluate the air purifier you want to buy. It’s really important to buy an air purifier based on what it will be used for. A brief description of each term is listed below. For more information, click the links:
- Filtration – All filters clean the air by filtering out common particles like dust, pollen, odors, smoke and other dangerous pollutants, like mold and asbestos, but they use different methodology and technology. The most common types of filters are as follows:
- HEPA. HEPA, a mechanical filter engineered to capture dangerous particles, is by far the most common fixture in air purifiers, and is probably the most efficient. Proper HEPA filters remove 99.9% of pollutants in the air.
- Ionization. The process of ionization changes the charge of a particle, and then draws it into the filter.
- Electrostatic. This filtration method is less common but can capture very small particles, and is often easy to wash and energy friendly.
- Ultraviolet. UV filtration attacks the DNA of organic material that causes bad odors and health risks, such as mold and mildew.
- Thermodynamic. This method uses heat to destroy impurities in the air.
- Hybrid. combines two or more of the foregoing air filtration methods in one air purification device.
- HVAC – A generic industry term for heating, ventilation and air conditioning systems that you could use to treat the air in your home or office.
- CADR – or Clean Air Delivery Rate. CADR was developed to measure effective an air purification system can be by calculating how many cubic feet of air a unit can filter in 1 minute, and a rating is given for three categories: dust, pollen, and smoke. The higher the CADR, the better it is in terms of purifying the air, so be sure to look for high CADR numbers, especially if you are in need of cleaning a big room, or a space that has a continuous source of air pollutants or smells. Alternatively, if you have a machine with low CADR, then you can move it around a room in order to mimic the effects of a high CADR.
- ACH – or Air Changes per Hour. This metric tells you how many times your air purifier will change the air in a given space per hour. The more powerful air purifiers will have a higher ACH. For example, “6 ACH” means the air will be cleaned every ten minutes (6 times per hour). The cubic volume of a room (or other space where the air purifier is turned on) is an important factor in determining how many times the air “changes” per hour. Rationally, the bigger the room, the longer it will take to change all of the air in it. If your system has a good fan (capable of high RPM), then you will have increased airflow (and that is good). A coarse filter could also affect the flow of the air through the machine, as can air flow in a room, which can be reduced by structures, furnishings, windows and other matters. The important thing to remember is that maximum operating speeds can be loud, and if you prefer a little peace and quiet, it’s a good idea to select an air purification device that will be suited for room larger than you need it to be.
- AHAM Certification – The Association of Home Appliance Manufacturers is the industry association that measures and evaluates the efficiency of air purifiers, and which has established the metrics you’ve learned about on this site: CADR (Clean Air Delivery Rate), and ACH. Say what you will about industry certification bodies generally, but AHAM certification is something you will want to look for.
- VOC – Volatile Organic Compounds are a specific kind of air impurity that you would want to use an air purifier to filer out. Thy are, as the name implies, organic material like mold, that will most likely get worse if not properly treated at the source.
Size and look are very important considerations. Don’t forget to think about how an air purifier will look in your room. Some of today’s models are very sleek, and some are more mechanical or medical-looking. Also, remember that a big unit in a small room can stick out like a sore thumb. Remember to check the dimensions of your air purifier, and measure your room to see if it will fit properly.
Features, Sensors and Indicators
Newer models of air purifiers give you many great tools to address whatever is making your air less than perfect. With so many products on the market, don’t be confused by all the marketing jargon. Here is what you need to know in assessing any air purifier before purchasing.
- Fan Speed. Most air purifiers can modify fan speed based on air quality measurement. This can help your machine be efficient and save money (on electricity). Most models have at least 3 settings so that you can speed up the rate at which the air is purified. You might wonder why you would want to do it slower, and the reason is that the faster the fan, the louder the noise it produces. If you wanted to sleep next to one, for example, it would probably be a better sleep with a quieter machine, and you would want to run it at it’s slowest setting.
- Remote Control. These can be dinky but also useful, especially for nurseries or places where you may not want to go into a room. Maybe you renovated your apartment but don’t want to enter the “construction zone” where the air purifier is running. Hello remote control.
- Size and Weight. Some air purifiers have wheels, which improve portability around a space. If you plan to use one machine all over a house, for example, this is a great feature, and keep in mind how a size and weight might affect or restrict your use of the air cleaner.
- Reminders. Most brands also now incorporate features that remind you to change or wash filters when it is time to do so. This will prevent you from spending unnecessarily on new filters, or worse, leaving filters unchanged for a long time, reducing your air purifier’s effectiveness, and wasting your electricity.
- Sensors. Some models use sensors to detect “bad” air particles. Some can even tell you what specific pollutants reside in your air, and, in addition, can decide to modify the fan speed to address the concentration of air pollutants it is sensing. This technology is termed “IntelliSense” and means you don’t really have to do anything except plug in your machine and turn it on.
- Wash vs Replace. If your air purifier doesn’t use a pre-filter, it may have a shorter life span, because the secondary and other filters will have to tackle the kinds of particles that the pre-filter would otherwise eliminate. If you have to replace your entire machine, that can be expensive. If you do have a pre-filter, that is probably best, and even better than that is if it is washable with a cloth or vacuum.
- Energy Use. Look for an Energy Star certification, which indicates low energy usage, and therefore electricity savings.
There are certain kinds of air purifiers that can make an enormously positive difference in your life. Likewise, there are others that will do nothing but empty your bank account. Hopefully we’ve explained the issues that are important to you, but please feel free to contact us with questions. There’s a lot to keep in mind! Don’t forget to think through all the factors when purchasing an air purifier!