How to Choose an AC Mounting Base

Getting the base right under an outdoor air conditioning unit matters more than it looks. A unit that sits flat on the ground, or on an uneven surface, can end up unlevel, noisy, sitting in water after rain, or slowly drawing in dirt and debris. The right base keeps the unit level, stable, off the ground and running quietly. This guide explains the main types of ground-mounting base, what each is best for, and how to choose the one that suits your install.

Base or bracket? Start here

The first decision is whether the outdoor unit goes on the ground or on the wall. This guide covers ground mounting. If ground space is tight, the surface is unsuitable, or the area is prone to flooding, a wall bracket may be the better route instead, and we cover that in our companion guide on choosing a wall bracket.

For ground mounting, the job of the base is simple: raise the unit off the ground, keep it level, and stop vibration turning into noise. The differences between the products come down to the surface you are working with and how much vibration control you need.

The types of AC mounting base, and when to use each

Condenser pad

A condenser pad is a single flat platform the whole unit sits on. It gives a clean, stable footing on a firm, reasonably level surface, and spreads the unit's weight evenly. It is the simplest option where you already have solid ground. As a guide, a pad measuring 880 x 460 x 50mm supports up to around 240kg, which covers most residential outdoor units.

Anti-vibration rubber feet and mounts

Rubber feet, and adjustable anti-vibration mounts, are separate supports that fit under the unit's mounting feet rather than a single platform. They lift the unit off the surface and absorb compressor vibration so it is not transferred into the ground or a hard surface like concrete or a rooftop. Adjustable versions (for example an M10 x 65mm anti-vibration mount) have the added advantage of letting you level the unit on a slightly uneven surface, which a fixed pad cannot do.

Floor mounting base, foot or block

A base block or floor mounting foot (available in sizes such as 400mm and 500mm) raises the unit higher off the ground than a thin pad. This extra height is useful where you want more clearance from pooling water, garden beds or debris, while still keeping the unit stable and level.

A note on drip trays

A galvanised condenser drip tray is not a base in itself, but it is often used alongside ground mounting to catch condensate and defrost water and direct it away, keeping the area under the unit clean and dry. It is worth considering as part of a tidy ground install.

Comparison: which base suits your situation

How to choose, in three questions

1. Is the surface firm and level? If yes, a condenser pad is the simplest choice. If it is slightly uneven, adjustable anti-vibration feet let you level the unit.

2. Is vibration or noise a concern? On hard surfaces like concrete or a rooftop, rubber feet or anti-vibration mounts make the biggest difference to how much noise transfers into the ground or building.

3. Do you need extra height off the ground? If water pooling, garden beds or debris are a concern, a floor base block or foot raises the unit higher than a pad. Add a drip tray to keep the area clean.

Whatever the surface, the goal is the same: level, stable, off the ground and quiet. Match the product to your surface and you will get all four.

Ground-mounting bases at Star Sparky

All of the base types in this guide are available at Star Sparky, ready to ship across Australia:

• Condenser pad (880 x 460 x 50mm, up to 240kg)

• Anti-vibration rubber feet mountings

• Galvanised adjustable anti-vibration mounts (M10 x 65mm)

• Floor mounting base block / foot (400mm and 500mm)

• Galvanised AC condenser drip tray

Not sure which suits your install? Call the team on 1300 996 996 and we can help you match the base to your unit and surface.