Correct Termination of Air Conditioner Condensate Drains
Every split system produces water, called condensate, in both cooling and heating modes, and that water must drain to a safe and compliant point. In Victoria, condensate drains are plumbing work that must meet the requirements set by the Building and Plumbing Commission (formerly the Victorian Building Authority). A drain that is not installed correctly can cause water damage, and flooding the room is just one example.
Where the water comes from
When humid air is drawn over the cold coil of an air conditioner, moisture in the air condenses on the coil. This condensate runs off the coil and must be drained away from the air conditioner, and the drain needs to be installed by a licensed technician.
In cooling mode the condensate is created by the indoor unit, and in heating mode it is created by the outdoor unit. A split system creates water in both modes. Concealed systems such as bulkhead air conditioners create condensate too, so the drain is planned as part of the installation.
How much water does a split system produce?
The amount of condensate a split system produces depends on the relative humidity on the day, and it is usually more than most people expect. The table below shows the maximum amount of condensate each capacity of split system air conditioner will generate.
| Capacity | 2.5kW | 3.5kW | 4.4kW | 5.2kW | 6.0kW | 7.0kW | 8.0kW |
| Litres per hour | 1.6L | 2.0L | 2.4L | 2.8L | 3.5L | 4.1L | 4.7L |
Where a condensate drain must terminate
If your air conditioner can generate up to 4.7 litres an hour, that water must drain to a point where it:
- Won't affect the health and safety of people nearby.
- Won't affect the integrity of surrounding buildings.
- Complies with Victorian plumbing regulations.
- Complies with any owners corporation (body corporate) rules.
Split system condensate drains in Victoria must follow the Building and Plumbing Commission's guidance. The earlier Technical Solution Sheet 7.08 has been superseded by practice note MS-07, split system air conditioning.
Do you live in a high rise apartment?
If you live in a high rise apartment without a drainage point for your split system, the water cannot simply drip, for example, 17 floors to the ground. It must be terminated to an approved point. EZYAIR can solve this by installing an evaporation pan as part of the installation. Learn more about our apartment air conditioning service.
The condensate drains into the pan, where an element heats the water so it evaporates out of the pan and into the air. There are two choices when selecting an evaporation pan:
- EVAP1: maximum evaporation of 2.4 litres per hour. A sensing probe turns the element on and off when required. Rated at 2.4kW.
- EVAP2: maximum evaporation of 0.18 litres per hour. No sensing probe, so it runs all the time. Rated at 700W.
Water leaking from your split system?
Water dripping from an indoor unit usually points to a drain problem. If your system is leaking, contact us or see our split system service options.
Frequently asked questions
Does a split system produce water in heating mode?
Yes. In cooling mode the indoor unit produces condensate, and in heating mode the outdoor unit does. A split system always creates water in both modes.
How much water does a split system produce?
It depends on the humidity and the size of the system. As a guide, the maximum ranges from about 1.6 litres per hour for a 2.5kW system to about 4.7 litres per hour for an 8.0kW system.
Where can an air conditioner condensate drain go in Victoria?
It must terminate at an approved point that is safe for people and buildings, in line with Building and Plumbing Commission requirements and any owners corporation rules.
What if my apartment has no drain point for a split system?
An evaporation pan can be installed so the condensate is heated and evaporated instead of being drained. EZYAIR installs these as part of apartment installations where needed.
Related guides
Keep reading with these related EZYAIR guides:
- What Is a Split System Air Conditioner?
- How Does a Split System Air Conditioner Work?
- Replacing a Split System: What to Check First
- VEU Accredited Provider and Air Conditioning Licences in Victoria
Talk to EZYAIR
Ezy Air Conditioning & Heating Pty Ltd (EZYAIR) has been helping Melbourne homes and businesses with heating and cooling since 2007. If you have a question about condensate drains or would like a quote, contact our team or call 1300 399 247, Monday to Friday, 9am to 5pm.
Our head office and display centre is at 49 Huntingdale Rd, Burwood VIC 3125.
