Air purfier to save on air conditionig?
No. You're being sold a big scam. Where is the heat going? If it's a machine that generates electricity inside and has no connection to the outside, it's going to increase the amount of heat in the building. If it's an HRV or ERV system that exchanges and filters outside air, that's a different kettle of fish, but those systems are also not going to cool the house at all.

If you want it cooler in your apartment, consider actual cooling systems, better shading, radiant barriers, or more insulation.