The answer to the question "Does an air purifier cool a room?" is negative in most cases. Typically, this device lacks air cooling mechanisms. According to their principle of operation, they fall into two categories.
- Air purifiers with fans circulate the air in a closed space through their mechanical, electrical or hybrid air filters. Unlike air conditioners, they don't cool the air before blowing it through the premise.
- Air purifiers without fans act like ionizers. They neutralize dangerous air particles.
You would hardly come across a device that has filters but lacks a fan and vice versa. A filter-less model does not blow out cold air. It does not influence the temperature inside the room.
If air purifiers work as a fan, we can classify them according to airflow directions. Tower-style devices feature linear air intake and outflow design. They draw air from the backside and deliver towards the front. Even though that's not cool air, purifiers with the forward airflow direction are optimal for summer because they don't make the room hotter. Plus, some of them use oscillating features like stand fans.
Models with the upward airflow direction draw the air from the front, back, sideways or use 360-degree directions. In this case, the answer to the question "Will an air purifier help cool a room?" is also negative. Moreover, in winter, such a device might make the room hotter because it will be pulling down the warm air from the ceiling (this process is called convection). The smaller the room, the easier it is to warm it up. If you install a purifier with an upward airflow direction in a large hall, it won't raise the temperature of the air too drastically.
A typical electric fan doesn't purify the air. Consequently, it can circulate larger amounts of air. Unlike fans, purifiers are equipped with filters. The more filters they have, the slower the air circulates and the less impact you feel. First, the fan sucks in the air in the system. Then, the air moves along as the filters do the rest of the cleaning work. The fresh air is then allowed to pass, as the fan pushes it out, creating some kind of breeze. If someone says that air purifiers cool down a room, they're probably talking about the power of the breeze. It might help you to cool down because it evaporates the water on your body and carries away the heat faster. But to feel the air moving over your skin you might need to sit next to the device. If you make just a few steps away, you would hardly feel any impact.
To estimate the strength of an air purifier, check its CADR (Clean Air Delivery Rate) rating, measured in cubic feet per minute. A typical purifier delivers from 80 to 300 CFM. An average desk or ceiling fan delivers over 1000 CFM, that's why the chill feeling from it is significantly higher.
Some people ask whether it is possible to install an air purifier and a fan in the same room and use them simultaneously. Yes, you can do it. Compared to an HVAC system, this might be a more cost-efficient solution. If you resort to it, it might be wise to turn off the fan when you sleep to avoid getting a sore throat.