DIY vs Professional Marine Air Conditioning Installation
A self-contained unit is within reach of a competent owner. Two parts of the job are not, and no amount of skill changes that — they are licensing questions, not ability questions.
DIY Mechanical Work and Licensed Installation Tasks
| Task | Who | Why |
|---|---|---|
| Mounting the unit | You | Bearers, vibration mounts, access for service. Ordinary boat carpentry. |
| Ducting and grilles | You | Short runs, gentle bends, return air larger than supply. |
| Condensate drain | You | Gravity fall to a sump or shower drain. |
| Through-hull and seacock | You, carefully | Legal to do yourself. A hole below the waterline is not the place to learn, and your insurer may have a view. |
| Seawater plumbing and pump | You | Double clamps, proper hose, pump below the waterline so it primes. |
| Refrigerant — charge, recover, connect | ARCtick licence | Anyone handling refrigerant in Australia needs one. Covers every split and chilled-water system, and any self-contained unit needing a re-gas. |
| Fixed 240 V wiring | Licensed electrician | Vessel electrical installations fall under AS/NZS 3004.2. Dedicated circuit, RCD, correct cable. |
This is why a self-contained unit is the DIY-friendly one. It arrives with the refrigerant circuit sealed and charged at the factory, so nobody has to touch the gas. A split system needs lines run and charged on the boat, which puts a licensed technician in the middle of the job whatever your skills.
Potential Labour Savings from DIY Installation
Take the common job — one 16,000 BTU self-contained unit on a 35–45 ft boat. Professionally installed it runs about $7.7k–$13.8k. Doing the mechanical work yourself and paying an electrician for the 240 V side takes out most of the labour but none of the parts.
| Line | Installed | Owner-fitted |
|---|---|---|
| Unit | $4.5k–$6.5k | $4.5k–$6.5k |
| Parts — seawater side, ducting, electrical materials | $1.5k–$3.8k | $1.5k–$3.8k |
| Yard labour, 15–25 h | $1.7k–$3.5k | — |
| Electrician, 3–6 h | included | $350–$850 |
| Total | $7.7k–$13.8k | $6.4k–$11.2k |
Roughly $1,300 to $2,600, or somewhere between fifteen and twenty per cent — for two or three weekends of awkward work in hot lockers, and the whole risk of the outcome. That is a real saving, and it is smaller than most people expect before they price it.
Below-Waterline, Electrical and Warranty Risks
Some makers require installation by an authorised dealer for the full warranty. Read the terms before you buy the box, not after.
A new hole below the waterline and a new 240 V circuit are both things an insurer may ask about after a claim. Unlicensed electrical work is the one that causes real trouble.
When it does not cool in January, an installer who fitted it owns the problem. When you fitted it, you own it — and diagnosing airflow against capacity against water flow takes experience.
A tidy professional install with paperwork adds confidence at survey. An obviously amateur one invites a discount larger than you saved.
Dividing Marine Air Conditioning Work with an Installer
Do the preparation yourself and buy the skilled hours. Clear the locker, build the bearers, plan the duct runs, work out where the condensate goes, and have the boat ready on the day. Then pay the yard for the through-hull, the commissioning and the electrical work.
It takes a meaningful bite out of the labour without putting your name on the parts that matter, and every installer we have spoken to would rather arrive to a boat that is ready than bill you for moving your gear out of a cockpit locker.