A pool house or cabana takes a different heat load than the main house, and the AC system that cools it needs to be sized and installed for that reality, not borrowed capacity from an indoor unit that already has its hands full.
- AC installation for pool house structures needs its own tonnage calculation, not a guess based on square footage.
- A dedicated ducted system beats sharing a zone with the main house for cabanas used most days.
- Salt air near the coast shortens outdoor unit life fast without coil protection built in.
- Single-stage equipment struggles with humidity in glass-heavy cabanas. Variable-speed systems handle it better.
- Permitting rules for detached structures differ between Palm Beach, Martin, and St. Lucie counties in 2026.
Why this matters
Pool houses and cabanas in Palm Beach County and the Treasure Coast almost always have more glass and less insulation than the main house. Sliding doors, screened openings, and block walls with minimal attic space push heat gain higher than a bedroom of the same square footage.
Homeowners often try to solve this the cheap way: run a long duct branch off the main system, or install whatever unit fits the mechanical closet. Both choices tend to leave the pool house running warm, humid, or both, and the fix later costs more than doing it right the first time.
Who this is for
This guide is for homeowners in South Florida who are finishing out a pool house, cabana, or detached guest structure and need it comfortable year-round, not just tolerable in April and unbearable by July. If you're deciding between a standalone system, a zoned extension, or a package unit, and you want a straight answer instead of a sales pitch, this is where to start.
What to look for in AC installation for a pool house
Sizing based on actual heat load, not square footage alone
A pool house with a wall of sliding glass doors facing west takes on far more heat than a windowless storage room the same size. Standard load calculations that only look at square footage will undersize the system and leave you running the compressor constantly without hitting the setpoint.
Get a load calculation done for the specific structure, glass orientation included. The AC sizing guide walks through how tonnage gets calculated for spaces like this, and it applies just as much to a detached cabana as it does to a bedroom addition.
Dedicated zone versus a shared extension
Running a duct branch off the main house system sounds simple, but it means the pool house and the main house fight over the same compressor capacity. If someone's in the cabana and the rest of the family is inside, one space loses.
A separate zone, or a fully standalone system, keeps the pool house independent. This matters more the more the space gets used, whether that's a home gym, a guest suite, or a full-time cabana bar. The second AC zone guide covers when a shared system stops making sense.
Humidity control built for an open, glass-heavy space
Pool houses see moisture from two directions: the pool itself and the outdoor air that comes in every time a screen door opens. A system that only cools without pulling moisture down leaves the space feeling clammy even at 74 degrees.
Variable-speed equipment runs longer at lower capacity, which pulls more moisture out of the air per hour of runtime. Single-stage units cycle on and off fast and barely touch humidity before shutting down.
Coastal corrosion resistance
Outdoor condensers near Boca Raton, Delray Beach, or any coastal stretch of the Treasure Coast take a beating from salt air. A pool house often sits closer to open air and more direct salt exposure than a condenser tucked against the side of the main house.
Coil coatings and cabinet materials rated for coastal exposure add years to the unit's life. Skipping this on a pool house install is one of the more expensive shortcuts a homeowner can take. The coastal salt air maintenance guide covers what salt exposure actually does to unprotected equipment over time.
Permitting for a detached structure
Palm Beach, Martin, and St. Lucie counties each handle permitting for detached structures a little differently, and a pool house is technically a separate structure even when it shares a property line with the main house. Electrical capacity for a new outdoor unit also needs to be confirmed before installation day, not discovered mid-project.
A licensed contractor pulls the right permit for the county and inspects the electrical panel capacity up front. Skipping this step is how projects get flagged during resale inspections years later.
Top picks for pool house and cabana AC
The clean install: dedicated standalone ducted system
The hook here is independence. A standalone system sized specifically for the cabana, typically 1.5 to 2 tons for a pool house under 600 square feet, runs on its own thermostat and its own schedule.
This setup handles daily-use cabanas well, especially ones with a kitchenette or a bathroom that add extra latent load. Verdict: Buy for any pool house used more than a few days a week.
The humidity control pick: variable-speed system for glass-heavy cabanas
For cabanas with floor-to-ceiling glass or multiple sliding doors, a variable-speed system in the 2 to 2.5 ton range holds indoor relative humidity closer to 50 percent instead of letting it drift to 60 or higher. That's the range where the space stops feeling sticky.
Ruud, Carrier, and Daikin all make variable-speed equipment in this size range, and A.R. Williams Air Conditioning installs all three as a certified Ruud Pro Partner, Carrier Authorized Dealer, and Daikin Comfort Pro. The best AC brands for South Florida homes breaks down how these manufacturers compare on humidity performance. Verdict: Buy for any cabana with significant glass exposure.
The efficient add-on: zoned extension off the main system
For a small cabana under 400 square feet with a short duct run back to the main air handler, adding a zone with its own damper and thermostat can work without installing a second full system. This keeps upfront equipment cost lower while still giving the pool house independent temperature control.
This only works when the main system has spare capacity to spare. If the main house AC is already sized tight for the house itself, adding a zone just spreads a shortage across two spaces. Verdict: Consider, but only after a load calculation confirms the main system has room.
The shortcut that backfires: single-stage package unit
A single-stage package unit sitting outside the cabana looks like the simple answer, and it's often what gets quoted first because it's the least equipment to install. The problem shows up in July and August, when the unit cycles on, cools fast, shuts off, and the humidity creeps right back up between cycles.
Occasional-use storage rooms can get by on this. A cabana with a bar, a bathroom, or daily foot traffic cannot. Verdict: Skip for any pool house getting regular use.
Get your pool house AC sized right
A technician can calculate load and walk through options before any work starts.
What to avoid
- Oversizing to be safe. A system too large for the space cools fast and shuts off before it removes moisture, leaving the cabana cold but humid.
- Running refrigerant lines too far from the main house condenser. Long, unsupported line sets lose efficiency and create leak points that are hard to access later.
- Skipping a dedicated thermostat. A pool house sharing a thermostat with the main house means whoever's inside the house controls the cabana's temperature too.
Comparison across the criteria
| Option | Best for | Tonnage range | Humidity control | Verdict |
|---|---|---|---|---|
| Dedicated standalone system | Cabana used most days | 1.5 to 2 tons | Good with variable-speed models | Buy |
| Variable-speed, glass-heavy setup | Cabana with heavy glass exposure | 2 to 2.5 tons | High, dedicated dehumidify mode | Buy |
| Zoned extension off main system | Small cabana, short duct run | Shares existing tonnage | Moderate | Consider |
| Single-stage package unit | Occasional-use storage space | 1.5 tons | Low, cycles on and off | Skip |
FAQ
What size AC do I need for a pool house?
Most detached pool houses under 600 square feet need 1.5 to 2 tons of cooling, but the right number depends on glass area and orientation. A load calculation on the specific structure is more accurate than a square-footage rule of thumb.
Can I run a second AC zone off my main house system for the pool house?
Yes, if the main system has spare capacity and the duct run to the pool house is short. If the main house AC is already sized tight, adding a zone spreads a shortage across both spaces instead of solving it.
Does a pool house need special humidity control?
Yes, because pool houses see moisture from the pool itself and from doors opening to outdoor air more often than a bedroom would. Variable-speed equipment pulls more moisture out per hour of runtime than single-stage units.
Will pool chemicals or salt air damage the outdoor AC unit?
Salt air near coastal areas of Palm Beach and Broward counties corrodes unprotected condenser coils faster than it would further inland. Coastal-rated coil coatings and cabinets extend the outdoor unit’s life significantly.
Do I need a permit to install AC in a cabana in Palm Beach County?
Yes, a detached structure like a pool house typically needs its own permit even when it shares the property with the main house. Permitting details vary between Palm Beach, Martin, and St. Lucie counties, so confirm with a licensed contractor before installation.
How long does AC installation take for a pool house?
A standalone system install for a detached pool house typically takes one to two days depending on electrical work and permitting timelines. Zoned extensions off an existing system can sometimes be completed in a single day.
Is a bigger AC unit always better for a pool house?
No, an oversized unit cools the space quickly but shuts off before it pulls moisture out of the air, leaving the room cold and humid at the same time. Correct sizing based on the actual heat load performs better than going bigger.
One last thing
The detail most homeowners miss on a pool house install isn't the equipment, it's the electrical panel. A dedicated standalone system needs its own circuit, and older homes built before 2010 often don't have the spare capacity sitting there waiting. Confirming panel capacity before quoting the job, not after, is what keeps installation day from turning into a second trip.
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