The “best” scent diffuser is the one that fits your space. A diffuser that’s too small never quite fills the room; one that’s much too big wastes oil. This guide walks through the sizing rules we use at Aromely and which ARO model fits each kind of space.
Four sizing rules
- Coverage ratings are maximums. Every rating below is the most a model can cover at a standard 8 ft ceiling. Leave about 20% headroom: for a 1,000 sq ft space, choose a model rated for at least 1,200 sq ft.
- Ceiling height matters. Scent fills volume, not floor area. With 10–12 ft ceilings, the same diffuser covers fewer square feet, so size up or add a second unit.
- Closed rooms each need their own diffuser. Scent doesn’t travel well through closed doors. One open-plan area can share a diffuser; separate bedrooms can’t.
- One HVAC diffuser per air system. An HVAC scent diffuser scents the zone served by one air handler. A home with two HVAC systems needs two units, not one larger one.
Which ARO diffuser fits your space
| Space | Model | Max coverage | Type |
|---|---|---|---|
| Bedroom, bathroom, small office | ARO BLISS | 500 sq ft | Plug-in |
| Living room, office | ARO X25 | 1,000 sq ft | Tabletop or wall-mount |
| Large living area, studio, small shop | ARO 25 MAX | 1,500 sq ft | Tabletop or wall-mount |
| Open-plan home, lobby, spa, showroom | ARO TOWER | 3,000 sq ft (open areas) | Floor-standing |
| Whole apartment or small home | ARO HOME | 1,800 sq ft | HVAC or standalone |
| Whole house | ARO PRO | 4,000 sq ft | HVAC or standalone |
| Large home, office, store | ARO MAX | 16,000 sq ft | HVAC or standalone |
| Large commercial facility | ARO VORTEX | 60,000 sq ft | Commercial HVAC |
Room-by-room or whole house?
Room by room works best when you want different scents in different spaces, or when you only want to scent a few rooms. Use a plug-in or tabletop diffuser in each one.
Whole house is simplest when you want the same scent everywhere. An HVAC scent diffuser connects to the air supply side of your system, so the scent travels through the vents into every room the system serves. ARO HOME, PRO and MAX can also run on their own as standalone diffusers.
Large open spaces: one big unit or several small ones?
Both work. A 4,000 sq ft open area can be covered by one larger unit, or by two ARO TOWERs, three ARO 25 MAX or four ARO X25 spread around the space. Several smaller units give more even coverage when the space is long or broken up by walls.
Oil for your diffuser
All ARO diffusers are waterless and use Aromely fragrance oils for waterless diffusers. Small models usually start with a 50–120 ml bottle; TOWER, PRO and MAX with 150–500 ml. Not sure which scent? Start with 20 ml samples.
Still not sure?
Tell us the size of your space, the ceiling height and whether rooms are open or closed, and we’ll recommend a setup. You can also compare all Aromely scent diffusers or browse commercial options for businesses.
