Ducted on the Central Coast
Plenty of houses
Separate houses make up most of the council area's homes, and a single-storey roof space is the easiest place to run ducts.
A wide spread of weather
Gosford's records run from 44.8 degrees in January 2013 down to minus 4.2 in July 1970. A system serving the whole house has to cope with both ends.
Coast and valley sizing
AdaptNSW's ranges put inland summers at 26 to 28 degrees and winter minimums at 4 to 6, against 24 to 26 and 8 to 10 nearer the coast. The same floor plan can need a different system depending on whether it sits near the water or inland.
Gas in the roof
Jemena supplies natural gas on the Coast. If your house already has gas ducted heating, you have two routes, compared below.
Already have gas ducted heating?
| Add-on cooling | Ducted reverse cycle | |
|---|---|---|
| The gas heater | Stays, and keeps heating in winter | Comes out, and reverse cycle does the heating |
| The ducts | Rinnai says most add-on systems reuse the existing ductwork and vents | New ducts throughout, because the ACT guide says gas ducts are too narrow |
| Will it work? | Rinnai says not every existing heater can support add-on cooling | Depends on roof space and access for new ducting |
| Warranty | Rinnai classes a retrofit component as 'Other Applications', with 2 years parts and 1 year labour | The brand's standard terms for a new system |
Zoning for a Central Coast house
Zone dampers in the ductwork open and close to send air only where it's wanted, ActronAir explains. Bedrooms in one zone and living areas in another is the layout Daikin uses as its example.
For a winter-heavy home inland, give the bedrooms their own zone so you can warm them before bed without heating the whole house. The ACT Government says heating only the areas in use is better for energy efficiency.
Remember the system works in one mode at a time. ActronAir says zones can only differ by 4 degrees, so it won't heat one end of the house and cool the other.
What makes the job bigger or smaller
A two-storey house, a low roof pitch or tight access into the roof all add time. Ducts through the ceiling also reduce your ceiling insulation, as the ACT Government notes, so ask how it'll be restored.
The ACT guide recommends duct insulation of at least R1.5 and warns that suppliers may not include it by default. A big system in a large house may also need 3-phase power, which the installer can confirm.
What a Central Coast ducted quote should include
- A room-by-room heat load, with heating sized for your end of the Coast.
- Heating and cooling capacity in kW.
- The zones, the controller and a sensor for each zone.
- Duct insulation rated R1.5 or better.
- Whether existing gas ducts are being replaced or reused, and why.
- Any 3-phase or switchboard work.
- The NSW licence number and the RTA number.
What we'd do
What we'd do
If the gas heater is getting old, we'd get both routes quoted side by side: add-on cooling to keep it, or full ducted reverse cycle to replace it. Then we'd choose on the state of the heater and the ducts, not the headline. Either way, we'd give the job to a ducted specialist who works on Central Coast houses every week and checks the ducts before quoting.
