Before we began, let's start the post by shooting ourselves in the foot. An air purifier will not change a room temperature regardless of the fan speed it's in. However, a fan with an air purifier functionality would be able to do that such as Dyson pure cool. Available in tabletop or taller tower fan, it is essentially a bladeless fan with a built-in HEPA air filtration. So in another words, an "air purifier cooler" combination does exist if that's what you are looking for.
Do Air Purifiers Cool Down A Room?
A standalone air purifier will NOT cool down a room. In fact, it will also NOT heat up a room. It is designed only to filter and circulate clean air from airborne particles and smoke. There is no cooling unit like evaporator coil or condenser coil in its setup. A typical air purifier is basically made out of a couple of filters and a built-in motor fan. Most people might think otherwise is because they feel a breeze of cool air that blows out from the outlet. This is what we would call “wind-chill” where the flow of lower temperature airflow provides temporary chills to our body. The effects are actually more noticeable when is the air cleaner is on higher fan speed or you’re sweating.
Opening windows or doors is our favorite as it can be done in a snap. However, there is the risk you will have to bear when you open more windows “opportunity” to the allergens. Regardless of which method you choose, you should always keep an air purifier running since it will not affect room temperature. It will help capture all in-flowing airborne contaminants like dust, mold, pollen, germs or even smoke.