Ductless mini-split installation scope of work

Short answer

A commercial ductless mini-split scope should list each outdoor unit and indoor head by room, define line set length and routing, specify condensate disposal, describe wall and ceiling penetrations and sealing, state the pad or bracket type, mark where electrical work begins and ends, and name the controller. Most disputes come from condensate routing and from power supply responsibility.

Key points

List every head by room name, not just a count. The room is what determines the mounting and the drain.
Single-zone and multi-zone systems need different scope language because multi-zone outdoor units serve several heads from one set of refrigerant ports.
Condensate is the most common cause of callbacks. The scope should define the termination point, not leave it to the installer.
Penetrations through fire-rated or weather-exposed walls need an owner decision about who seals and finishes them.
Electrical stops at a disconnect the scope names. Anything beyond that boundary should have a named licensed party.

Single-zone or multi-zone changes the paperwork

Ductless systems fit server closets, additions, back-of-house rooms, tenant spaces with no duct path, and buildings where a rooftop unit cannot reach. The scope starts with a simple choice: one outdoor unit for one head, or one outdoor unit feeding several heads.

Question	Single-zone	Multi-zone
Outdoor unit count	One per head	One serves several heads
Line sets	One pair per system	One pair per head back to the outdoor unit
Capacity matching	Straightforward	Combined indoor capacity must fit the outdoor unit's allowed range
Failure impact	One room	Every connected room
Scope risk	Many small units, many pads	Longer line runs, more penetrations

If a building is heading toward six or more heads, compare against a branch-box system in the VRF installation scope of work. Past that point the economics and the maintenance picture often change.

Heads, rooms and mounting

A scope that says "install four ductless heads" is ambiguous. A scope that says "install a wall-mounted head in the break room, a ceiling cassette in the front office, and a floor console in the server alcove" can be priced and verified.

Wall-mounted heads: Mounting height, wall construction (stud, masonry, storefront), and whether blocking exists behind the finish.
Ceiling cassettes: Ceiling type, grid size, support from structure, and a place for the condensate to leave.
Ducted slim units: Concealed above a ceiling, with short duct runs and grilles. Say who supplies grilles and flex.
Floor consoles: Useful along exterior walls; confirm clearance for returns and cleaning.

Line sets, penetrations and sealing

Line sets run from the indoor head to the outdoor unit, carrying two copper lines, a condensate drain, and a control cable. Their path is the part of the job a facility manager sees every day, so the scope should describe it.

State the route: through the wall, over the ceiling, down a chase, or along the exterior in a line set cover.
State maximum length and rise permitted by the manufacturer, and compare it with the installed route.
Specify insulation, weatherproof wrap, and line set covers for exterior runs.
Define penetration sealing: sleeves, sealant and firestop where the wall carries a rating.
Identify who patches, paints and finishes the wall or ceiling after the penetration is made.

In retail and restaurant buildings, exterior line sets are visible to customers and sometimes regulated by a landlord. Check the lease, and put any landlord approval requirements in the scope as an owner responsibility.

Condensate: the quiet failure point

Ductless heads sweat heavily in humid weather, and the water has to go somewhere that is legal and accessible. Gravity drains are best. Where there is no slope, a condensate pump is acceptable but adds a part that can fail.

Name the drain termination: indirect connection to a waste line, an exterior discharge, or a tailpiece over a floor drain.
Say whether a pump is included, and whether a float switch will shut the head off before overflow.
Keep drain lines out of freezing, sunlit or traffic zones where algae and damage are likely.
Confirm local plumbing requirements, which vary by jurisdiction.

A pump in a ceiling above finished space needs an access plan. A commercial repair visit for a drain overflow is much easier when the pump was left reachable.

Pads, brackets and outdoor placement

Outdoor units sit on pads, wall brackets, roof rails or stands. Each has different owners and different approvals.

Mounting	Good for	Scope note
Composite or concrete pad	Ground-level yards, service alleys	Who pours or sets the pad, and is the grade sloped away from the building
Wall bracket	Tight alleys, limited ground space	Wall must carry the weight; confirm anchors into solid substrate
Roof rail or stand	Flat roofs	Roof penetration or curb flashing is a roofing item; name the roofer
Hung from structure	Special cases	Requires a structural review by the responsible party

Davinci's work covers setting the equipment and connecting refrigerant, controls and condensate. Pad pouring, structural review and roof flashing are other trades, and the scope should say who handles them.

Electrical demarcation and controls

Ductless systems need a branch circuit to the outdoor unit and sometimes to the indoor head, a local disconnect, and a control path. The usual and cleanest split: a licensed electrical party provides the circuit up to and including the disconnect, and the mechanical crew lands the equipment connections and the inter-unit control wiring.

On controls, state whether each head uses its own remote, a wired wall controller, or a central controller. A small office with a wall remote per room is very different from a clinic that wants schedules and lockouts. For larger sites that need scheduling and logging, see the building automation controls upgrade scope and the VRF and split systems service page.

Sample scope language

Contractor shall furnish and install one outdoor unit and the indoor heads listed by room on the equipment schedule, with line sets, insulation, condensate piping to the termination points shown, and controls as specified. Owner shall provide the branch circuits and disconnects through a licensed electrical contractor, and shall approve all penetrations before work begins. Patching and finishing of walls and ceilings after installation is by others unless stated.

Frequently asked questions

What belongs in a ductless mini-split scope of work?

A room-by-room head schedule, outdoor unit locations and mounting, line set routes and lengths, condensate termination, penetration sealing, electrical boundary, controller type and startup. Add who patches walls and ceilings, since that is the item most often left undefined.

How far apart can the indoor and outdoor units be?

Each model has a maximum line set length and a maximum vertical rise or drop, published in the manufacturer's installation manual. The scope should compare the real route with those limits before ordering. Longer runs may need additional refrigerant.

Who handles the electrical connection?

A licensed electrical contractor named in the scope typically provides the branch circuit and disconnect. The mechanical crew connects the unit and the control wiring between components. The owner or GC should confirm who performs the electrical work before bids are compared.

Where should the condensate drain go?

To an approved indirect waste connection, an exterior discharge location that does not cause damage or icing, or a floor drain with an air gap. If gravity drainage is not possible, a pump with a float safety is a common choice. Local plumbing requirements vary, so confirm them.

Do ductless systems need a permit?

In most California jurisdictions, a new mechanical installation requires a mechanical permit and may trigger energy code documentation. Requirements differ by city and project size, so confirm current rules with the local building department. The Title 24 permits guide explains the general process.