17/06/2026
Do You Need to Replace the Ductwork When Upgrading Your Ducted Heater?
When quoting to replace an existing ducted gas heater with a new refrigerated ducted air conditioning system (with or without the VEU rebate), one of the most common questions we get is:
"Do I need to replace my ductwork?"
In many cases, the answer is yes, and there are two main reasons why:
1. Airflow Requirements
A ducted gas heater and a refrigerated air conditioning system have very different airflow requirements.
When a gas heater is operating, the airflow is reduced, allowing the air to spend more time passing over the heat exchanger and absorb more heat.
A refrigerated system, however, needs to provide both heating and cooling. Cooling requires significantly higher airflow to operate efficiently and deliver the correct performance. Existing ductwork installed for a gas ducted heater is often undersized for a refrigerated system, which can lead to poor performance, higher running costs, and reduced comfort.
2. Ductwork Condition and Insulation
Ductwork doesn't last forever.
Over time, the outer lining and insulation can deteriorate, especially in hot roof spaces. On a recent installation, we removed the existing ductwork and found it was so brittle that it literally fell apart during removal.
Damaged or poorly insulated ductwork can result in:
Energy loss
Reduced system efficiency
Higher running costs
Uneven temperatures throughout the home
Replacing old ductwork ensures your new system performs as it should for many years to come.
If you're considering a ducted air conditioning upgrade or would like advice on whether your existing ductwork is suitable, get in touch with the team at GT HVAC & Electrical. We'd be happy to assess your system and provide expert recommendations.
