Two distinct types of evaporative cooler are used in Melbourne homes: rooftop ducted systems that deliver cooled air to every room through ceiling outlets, and portable floor-standing units that cool the immediate area around the user. For Melbourne homeowners deciding between a new installation, a replacement, or a stop-gap cooling solution, understanding the performance and cost differences is essential.
How Ducted and Portable Systems Differ
Ducted rooftop evaporative coolers
A ducted evaporative cooling system consists of a rooftop unit housing the evaporative pads, fan, and sump, connected via ceiling ductwork to multiple outlets throughout the home. The fan moves a large volume of air — typically 2,500 to 5,000 litres per second — drawing hot outside air through the wet pads and distributing the cooled air to every room simultaneously. The system is permanently installed and requires a roof penetration, ceiling ductwork, and a mains water connection. It is the standard evaporative cooling solution for Melbourne established homes.
Portable evaporative coolers
A portable evaporative cooler (“swamp cooler”) is a freestanding unit that uses a small water reservoir and fan to produce a localised cooling effect. It requires no installation, moves between rooms, and operates from a standard 240V power point. It must be positioned near an open window to provide an exit path for the humid air it generates. Portable units move far less air than ducted systems (typically 300 to 800 litres per second) and cool only the immediate area around the unit — not the whole room.
Cooling Performance Compared
| Feature | Ducted Rooftop | Portable Unit |
|---|---|---|
| Coverage area | Whole home (all ducted rooms) | Immediate vicinity (1–2 m) |
| Temperature drop (ideal Melbourne day) | 8–14°C below outside temp | 3–6°C at close range |
| Airflow volume | 2,500–5,000 L/s | 300–800 L/s |
| Humidity day performance | Reduced but still functional | Minimal on humid days |
| Installation required | Yes — roof unit, ductwork, water supply | No — plug in and use |
| Power draw | 300–600 W | 50–150 W |
| Capital cost (Melbourne) | $1,500–$5,500 installed | $80–$400 (purchase) |
The key performance insight: a ducted system can make a 40°C Melbourne day feel like 26 to 30°C inside. A portable unit on the same day will produce a modest breeze that feels somewhat cooler than the ambient air but does not materially reduce the indoor temperature across the room.
Installation and Running Costs
Ducted system — installation
New ducted installation with no existing ductwork in a Melbourne medium home (three to four bedrooms): $3,000 to $5,500. Replacement unit into existing duct infrastructure: $1,500 to $2,500. Annual service and maintenance (service, pads, winterising): $600 to $1,200 per year. Seasonal electricity cost (50 operating days at eight hours per day): $43 to $87. The total cost of ownership over ten years for a ducted system (installation, maintenance, electricity) is approximately $8,000 to $16,000 for a medium home.
Portable unit — purchase and running
Purchase cost: $80 to $400 for a quality portable evaporative cooler. Annual running cost (same 50 days, eight hours): $12 to $36. No installation or maintenance costs. The total cost of ownership over ten years for a portable unit is approximately $200 to $800 — but it provides a fraction of the cooling coverage and performance of a ducted system.
Which Suits Your Melbourne Home
Ducted rooftop suits
- Melbourne homeowners in established brick or brick-veneer homes in the eastern, south-eastern, and northern suburbs — Doncaster, Box Hill, Ringwood, Frankston, Greensborough, Reservoir — where roof and ceiling space is accessible
- Families needing whole-home cooling across multiple bedrooms and living areas
- Properties where evaporative duct infrastructure already exists from a previous system
- Households seeking the lowest possible running cost for whole-home cooling
Portable unit suits
- Renters who cannot modify the property
- Supplementary cooling in rooms not served by the main ducted system
- Single-person use at a desk or bedside for overnight cooling
- Temporary cooling while a ducted system is awaiting service or replacement
- Inner Melbourne apartments where roof installation is impossible
Upgrading from Portable to Ducted
Melbourne homeowners who currently use portable units but own their property and have suitable roof access are strong candidates for ducted installation. The conversation typically happens after experiencing the limitations of portable cooling on a 40°C Melbourne northerly day — when the portable unit makes a marginal difference and the whole family is uncomfortable in multiple rooms simultaneously.
The assessment for ducted installation covers: roof space access (cathedral ceilings or very low roof pitch can be limiting); ceiling material and structure (older fibrous cement ceilings need careful handling for outlet installation); existing roof penetrations or previous evaporative infrastructure; and the water supply connection.
FreshDuct provides free site assessments for ducted evaporative cooling installation across Melbourne. We install Brivis and Breezair/Seeley units with full warranty on parts and labour. Call 0431 918 137 or book online for an obligation-free assessment.