Portable Air Purifier
A portable air purifier is a very convenient thing to have if you often go on business or personal trips and are very conscientious about your respiratory health. Not many hotels offer purifiers in their rooms, and if you are going to a friend or family's house for a few days they may not either. It is better to be safe than sorry with your respiratory health, and even if you only use it once in a while you can still have it set up in a room in your own home.
These style of air purifier are generally much smaller than your average models for easy transport. Some are even small enough to fit into a backpack or just carry in one hand. In this respect, they are very convenient. If you felt the need, you could just carry it with you room to room in the house, which is an option if you need a purifier but don't want to spend a great deal of money on one.
The one problem with a portable air purifier is that they are not very powerful. While normal-sized models can easily keep a whole room's air free of any airborne dust or allergens, the portable-sized models are not able to do that. Their size hinders their ability to have any sort of wide-range effect and it is difficult to fit a high power filtration system into a very small shell. Some of the more expensive units can pull in about half a room's worth of air, but even they cannot cover a large expanse. That is just the limit of the technology for the time being.
They make up for their lack of power in their portability and price. Some of the portable air purifiers on store shelves are one fourth the price of a normal sized purifier, which is great if you're running on a budget. If you keep them near you while they are on they can be a great help towards keeping you safe from breathing in harmful airborne particles and dust.
These are very useful if you are on a very tight budget or often find yourself on the road staying in hotels that do not provide any type of air filter to their customers. However, if you are looking for an air purifier to cover a large or even the whole expanse of a normal-sized room consider looking for something a little bigger. There is a whole world of purifiers on the market, and only a small fraction of them can be called a portable air purifier. No matter what you're looking for power-wise, there is an air purifier out there for you.