New Delhi, Dec. 11 -- It's funny how we spend our whole lives breathing, yet most of us barely think about the air that carries us through each day. It is only when you sit down at home after a long day, take a breath and something just feels. wrong - your chest feels tight or your skin prickles. That is where humidifiers and air purifiers step in. They're really helpful tools for restoring a sense of ease inside your own walls. Before understanding why the combination works so well, let's look at what they do.

A humidifier will add moisture to your room's air by releasing a fine mist or warm steam that nudges humidity into a comfortable range, usually between 30 and 50 percent. When indoor air drops below that, that's when people usuall...