Mini Split Installation in a Brooklyn Brownstone: What to Expect

If you're thinking about installing a ductless mini split system in your Brooklyn brownstone but aren't sure what the process looks like — this is the walkthrough.

We install these regularly in Park Slope, Carroll Gardens, Cobble Hill, Fort Greene, and Prospect Heights. Here's exactly what happens from first call to finished system.

Step 1: The Site Assessment (1–2 hours)

Before we give you a price or recommend equipment, we visit the home. We're looking at:

• How many rooms need cooling (and heating, if you're using it year-round)
• Where we can mount the indoor units
• Where the outdoor compressor will go — rooftop, backyard, or bracket-mounted on the exterior
• The electrical panel — mini splits need a dedicated circuit, and older Brooklyn buildings sometimes need a panel upgrade
• How we'll run the refrigerant lines from indoor to outdoor (through walls, up to the roof, etc.)

This is free and takes about an hour. We leave with enough information to give you a firm written quote.

Step 2: Choosing Equipment

We work with Fujitsu and other top-tier brands. For a Brooklyn brownstone, the most common setup is:

• Single zone: One outdoor unit, one indoor air handler. Good for an apartment or a single large floor. $5,000–$9,500 installed.
• 3-zone: One outdoor unit connected to 3 indoor air handlers — the most common setup for main living floors. $12,000–$22,000 installed.
• Whole-house (5+ zones): Covers every floor of a full brownstone. $20,000–$60,000 installed depending on equipment, electrical, and access.

We'll recommend what actually makes sense for your space — not the most expensive option.

Step 3: Installation Day

For a single-zone system, plan for a full day (6–8 hours). Multi-zone systems in a full brownstone typically take 1.5–2 days.

What we do:

1. Mount the indoor units — we drill a hole through the wall (typically 3 inches) for the line set, then secure the mounting plate and hang the air handler
2. Run the refrigerant lines — copper lines run from each indoor unit to the outdoor compressor, typically along the exterior in clean white line hide
3. Install the outdoor compressor — on the roof, on a ground pad in the backyard, or on a wall bracket
4. Electrical work — we run a dedicated circuit from the panel to the outdoor unit and low-voltage control wiring to each indoor unit
5. Vacuum and charge — we pull a vacuum on the system to remove air and moisture, then release the refrigerant pre-charged in the lines
6. Test everything — we run the system in both cooling and heating mode, check temperatures and airflow at each unit, and confirm everything is communicating

What the Finished System Looks Like

Indoor units are wall-mounted, typically high on the wall near the ceiling. They're about 30–36 inches wide and 10–12 inches tall — sleek and quiet. Most customers don't mind the look once they're in; they blend into the room better than expected.

The outdoor unit is roughly the size of a large suitcase. On a rooftop, you usually can't see it from the street.

Refrigerant lines run in white or beige line hide along the exterior of the building, or through interior walls where the layout allows.

What to Have Ready

• Access to your electrical panel
• Clear path to where indoor units will be installed
• Rooftop access if the outdoor unit goes up top
• Building access for 2 technicians for the full installation day

Ready to Get Started?

Call or text (347) 997-3360 or fill out our contact form. We'll schedule the site assessment and get you a written quote, usually within a week.