Recommended by many doctors, HEPA purifiers are the most effective and widely used of all air purifiers in America today. The HEPA purifier employs a filtration system that is ideal for patient suffering from asthma or severe cases of allergies. HEPA purifiers usually consume a lot of energy and therefore are not generally used for the whole house. It is best to have two units of this - one for the living room and the other for the bedroom. This also ensures that it has to work on limited space, which would result in better cleansing.
HEPA which stands for High Efficiency Particulate Air filter are the most effective when it comes to remove the suspended particulates in the air compared to other peruvian hair purifiers. These filters can be used alone as a purifier or may be used in conjunction with other methods of air purifying. Like the ionic air purifying technique.
That HEPA purifiers are highly effective cannot be questioned. A HEPA filter is good enough to catch any particulate above the size of 0.3 microns. Microns is the unit to measure the particulates floating in air. Since they are extremely small we use a separate unit to measure them. To give you an idea, a normal human hair weaves is about 100 microns thick. Now we know how effective HEPA purifiers can be. In fact a HEPA purifier working in its prime condition can purify the air up to a level of 99.97%.
However, HEPA can be ineffective in some special cases. For example HEPA filters wouldn't be able to deal with gases and odors. It will also not be able to deal with anything smaller than 0.3 microns. That means a large portion of microorganisms, including harmful bacteria and viruses will go free. You need to deal with them separately.
Another issue with HEPA purifiers is that it is generally noisy. Since a fan is used to draw in the air from the room a motor needs to work constantly. The sound of the motor is what creates the noise. The solution to this is to go for a higher capacity purifier than you actually need so that you can use it at medium to low speed.
If you are going for the basic versions of air purifier it is always advisable to opt for HEPA. If you plan to buy a more advanced device then HEPA filter will come along with other methods of purifying air, together in a single package.