Choosing the Right AC Indoor Unit
The indoor unit is the part of an air conditioning system you see and feel. Choosing the right type affects comfort, running costs, noise and how discreet the installation looks. Below we explain the five main commercial and residential AC indoor unit types, where each works best, and the trade-offs involved.
If you are unsure which suits your space, our engineers can survey the property and recommend the best layout, capacity and unit format for your budget.
Wall-Mounted Units
Best for: Offices, homes, shops and small commercial rooms
Wall-mounted units are the most common indoor unit type. They sit high on the wall, blow conditioned air across the room and are the most cost-effective option for cooling or heating a single space. Modern units are slim, quiet and Wi-Fi enabled.
Pros
- • Lowest installed cost
- • Quiet operation
- • Easy to maintain
- • Good airflow coverage
Cons
- • Visible on the wall
- • Limited to one room per unit
- • Needs suitable wall space
Ceiling Cassettes
Best for: Offices, shops, restaurants and open-plan areas
Ceiling cassettes sit flush within a suspended ceiling and blow air in four directions. They are discreet, distribute air evenly and fit standard 600×600 ceiling grids, making them ideal for commercial spaces.
Pros
- • Discreet, flush finish
- • 4-way airflow
- • Ideal for grid ceilings
- • Even temperature distribution
Cons
- • Needs ceiling void
- • Higher install cost
- • Not suitable for solid ceilings
Ducted Units
Best for: Premium homes, hotels, boardrooms and retail
Ducted units are hidden in the ceiling void and deliver conditioned air through slim grilles. Only the grilles are visible, giving the cleanest architectural finish and allowing multi-room zoning from one unit.
Pros
- • Almost invisible
- • Multi-room zoning
- • Premium aesthetic
- • Can integrate fresh air
Cons
- • Highest install cost
- • Needs ceiling void space
- • More complex maintenance access
Floor-Standing / Console Units
Best for: Period properties, conservatories and rooms with no high wall
Floor-standing or console units sit at low level, often under a window or against a wall. They are useful where high walls are unsuitable or where heating performance matters as much as cooling.
Pros
- • Good for heating
- • No high wall needed
- • Easy to reach filters
- • Works in conservatories
Cons
- • Takes up floor space
- • Can be more visible
- • Air distribution can be lower
Ceiling-Suspended Units
Best for: Restaurants, showrooms, warehouses and large open spaces
Ceiling-suspended units hang below the ceiling and throw air over long distances. They are powerful and do not need a ceiling void, making them ideal for high or open spaces.
Pros
- • Long-throw airflow
- • No ceiling void required
- • Powerful cooling
- • Good for high ceilings
Cons
- • Visible unit
- • Can be noisy at high speed
- • Industrial appearance
Quick Comparison Table
| Unit type | Best for | Visibility | Typical cost |
|---|---|---|---|
| Wall-mounted | Homes, small offices | Visible on wall | Lowest |
| Ceiling cassette | Offices, shops, restaurants | Flush in ceiling | Medium |
| Ducted | Premium homes, hotels | Only grilles visible | Highest |
| Floor-standing / console | Period properties, conservatories | Low on wall/floor | Medium |
| Ceiling-suspended | Warehouses, showrooms | Visible below ceiling | Medium-high |
FAQs
Which AC indoor unit is best for an office?+
Ceiling cassettes are usually best for offices with suspended ceilings because they are discreet and distribute air evenly. Ducted systems are the premium choice for boardrooms and client-facing areas. Wall-mounted units work well in smaller offices or meeting rooms.
Can different indoor unit types connect to the same outdoor unit?+
Yes. Multi-split and VRF systems allow a mix of wall-mounted, cassette, ducted and console indoor units to connect to one outdoor unit or plant, as long as the system is designed and commissioned correctly.
Are ceiling cassettes more expensive than wall-mounted units?+
Yes. Cassettes typically cost more to supply and install because they require a suspended ceiling or ceiling void, four-way airflow setup and sometimes a condensate pump. However, they look better in commercial spaces and cover larger areas.
What is the quietest indoor unit type?+
Modern wall-mounted and ducted units are generally the quietest, with some operating below 20 dB on low fan speed. Ceiling cassettes and suspended units can be quiet too, but they move more air and may be slightly louder.
Can I use a floor-standing unit for heating?+
Yes. Floor-standing and console units are often chosen for heating because they sit low and warm air rises naturally. They work well in conservatories, garden rooms and properties without suitable high walls.