The Honeywell HPA304 AllergenPlus is a high-capacity unit built with a focus on powerful air movement. It uses a "brute-force" engineering approach, relying on a high-torque motor and a large filter area to move air quickly through a room. This makes it particularly effective in larger, open-concept spaces where other smaller units might struggle to maintain consistent air quality. The housing is made of a matte-finish polymer that is designed to resist discloration and stay looking new for years.
Inside the unit, there are three separate HEPA filters and a large pre-filter. This mechanical setup is simple and durable, with no complex firmware or Wi-Fi chips to manage. Because it is a more powerful machine, it does create a noticeable "white noise" on its highest settings, which many people find helpful for sleeping, though it is much quieter on the lower "Germ" and "Allergen" settings.
- High air exchange rate makes it very effective for rooms up to 465 square feet.
- Mechanical controls are simple to operate and work well with external smart plugs if desired.
- Triple-HEPA filtration provides a massive surface area for capturing household dust and pollen.
Maintenance is straightforward: the front panel pops off to allow for easy access to the filters. One tip for new owners is to make sure the plastic wrap is removed from all four filters before turning it on for the first time. The controls are located on top, and while they are bright, they are easy to see and adjust even in low light.
If you prefer a smaller, more modern unit with built-in sensors and a laser-accurate air quality display, the PuroAir 240 is an excellent alternative. You can browse our full range of powerful filtration systems in the HEPA air purifiers section.
