Air-Purifier Buying Guide :
Living in a metropolitan city means that you are exposed to toxic airborne particles on daily basis. There are lot of dust particles, pollen and unhealthy odours in the air which can be avoided by using air-purifiers at home or cars. They are really advisable for people suffering from asthma or other allergies. You need to consider certain things before buying an air-purifier.
Use of an Air Purifier :
They are equipped with HEPA filters (High Efficiency Particulate Air filters) which can eliminate 99.97% of airborne allergic particles (which includes pollen, dust, pet hair, dust mites etc) of size 0.3 microns and larger.
Size of an Air Purifier :
Before choosing the exact size of an air purifier, you need to calculate the square footage of the room you want to purify. This is done by measuring the length and width of the effective area in feet and multiplying them. Opt for an air purifier with a recommended square foot coverage area that matches your room’s square footage by referring its specifications. An air-purifier takes about 15-20 minutes in purifying the air and then recirculate it depending upon the size of a room. For best results, we can buy a slightly bigger air purifier than the rated room size. Also, it is more effective with closed doors and windows as then it does not have to purify the dirty air constantly.
Required features of an Air Purifier :
After choosing the size and type of air purifier, you need to analyse whether you would prefer any special features. Additional features may include caster wheels, handles for easy mobility, digital controls, remote controls, multiple fan speeds, built-in humidifier, sleep mode, child lock, filter change indicators, programmable timers, air quality sensors and more. These features enhance the performance of the device and provides lot of convenience while operation.
Types of Air-Purifiers :
1. Room Purifiers :They are best suited for homes having centralised heating or cooling. The commonly used models are light-weight weighing about 5-10 kg. They are portable with handle and moving stand whereas the heavier models have wheels. The latest models are equipped with cleanable HEPA filters to reduce the operating cost. The models using ionizer technology should be avoided as they emit large amount of ozone which is harmful for health.
2. Industrial Purifiers :These type of purifiers are more powerful and expensive than consumer models. They are mainly used by companies which require contaminant-free environment for manufacturing. Some companies use a massive air circulation and filtration system that purifies the air in very short time span (i.e, 10 times per minute) but they have very high initial cost and operational cost.
Types of Air-Filters :
1. HEPA Filters :HEPA stands for High Efficiency Particulate Air and are used to remove the dust particles from the air. They can trap almost 99.97% of contaminated airborne particles as small as 0.3 micron size and hence recommended by Allergists and Doctors to filter the household air. They can easily remove bigger air contaminants like pollen (5-100 microns), mold (2-20 microns), bacteria (0.35-10 microns), pet dander (0.5-50 microns) etc. but they are not able to capture the particles smaller than 0.3 microns like chemicals, fumes and cigarette smoke. Hence it is advisable to purchase a HEPA air filter which includes activated carbon filter to trap minute allergens also.
2. Activated Carbon Filters :They have very small absorbent pores which react with the pollutants as they pass through the filter. The pollutants bond with the carbon and get trapped, hence helping in cleaning the air effectively. These filters cannot be used alone and work well in conjunction with other filters.
3. Ultraviolet Light Filters :They use rays of ultraviolet light to destroy the bacteria and other contaminated particles by breaking the molecular bonds in their DNA. They are commonly used in sterile environment like hospitals, kitchens, daycares and labs.
Where will I put my Air Purifier?
It should be kept in bedroom as you tend to spend most of your time there. Do not place them in corners or too close to walls. Keep them in a comfortable and open place and do not pack them between the furniture pieces. The portable air purifiers are medium sized and they are sufficient to purify one room only, hence you would have to invest in additional units for other rooms. Alternatively, you can purchase the models with caster wheels and handles so that they can be moved easily from one room to another. The whole house air purifiers are also becoming popular for cleaning air in each and every room in the house as they directly connect to your home's existing HVAC system to purify, heat , cool and ventilate your indoor space.
Portability and Weight :
Central purifying device for the whole house is quite expensive and may not be useful for most consumers. Hence, opt for medium sized air-purifier with good performance according to your room size. However, a smaller size air-purifier may look good but it may not be that effective in cleaning the air due to its lower capacity.
What capacity to choose?
The performance of an air-purifier is determined by CADR ratio (clean air delivery rate). CADR indicates the maximum square footage recommended to use the filter and how quickly it can remove the three types of pollutants: smoke (with a number ranging from 10 to 450), dust (10 to 400), and pollen (25 to 450). Higher the CADR number, more effectively the machine filters the air. The ideal value is 300 and anything above that is excellent. Lower than 100 is of very poor value and does not purify the air.
If you go for a cheap air purifier withe less warranty period, then it may not be as effective and you may have to replace the unit soon. It is always better to buy an air purifier of reputed and trusted manufacturer with a comprehensive warranty. There are lots of brands selling this equipment but for accuracy and credibility, it is better to opt for popular brands like Philips, Panasonic, Eureka Forbes, Kent, Breathwell and more.