Home » RoughinBox RBX3-MD-NC Recessed Wall Box for Drain and Lines
Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
À quoi ça sert – Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
Fiche technique – Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
À savoir avant l’installation – Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
À quoi ça sert – Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
Fiche technique – Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
À savoir avant l’installation – Boîtier mural encastré RoughinBox RBX3-MD-NC pour drain et lignes
MarketAir

RoughinBox RBX3-MD-NC Recessed Wall Box for Drain and Lines

In stock

MarketAir’s recessed box that takes the lines, cable and drain behind a wall-mount heat pump’s indoor unit.

AirGreen codeAG-DR-004

14-1/2 × 8 × 3-1/2 inrecessed box
3/4 in NPTmale drain outlet
16 in studswood or metal
New constructionRenovation
Ask for a quote

514 316-2973 · sales@airgreen.ca

Quick facts

AirGreen codeAG-DR-004
BrandMarketAir
Model no.RBX3-MD-NC
MaterialPolyethylene
MountingBetween studs at 16 in centres
Drain3/4 in male NPT outlet

The RoughinBox RBX3-MD-NC from MarketAir is a recessed wall box installed in the wall behind the indoor unit of a wall-mounted heat pump. The refrigerant lines, the cable and the condensate drain come into it, and the connections stay hidden behind the unit while remaining accessible.

A clean rough-in for new construction and renovation

In a new home or a major renovation, the lines can run inside the walls before the drywall goes up. The RoughinBox mounts between two studs spaced 16 in apart, wood or steel, thanks to its built-in adapters. Its sloped bottom directs water to a 3/4 in male NPT drain outlet, which can be turned horizontal or vertical and connected to a plumbing drain. The box is reversible, so the lines can exit on the left or the right.

Manufacturer specifications

  • Overall dimensions: 14-1/2 × 8 × 3-1/2 in; front opening of 13 × 3-3/4 in
  • Two line ports on top (2-1/2 × 3-3/4 in), one on the bottom (4 × 3 in), two optional side ports
  • 1/2 in and 3/4 in cable entries
  • One-piece moulded polyethylene, rounded edges at the ports so the insulation does not tear
  • Hinged front plate and removable back for access to the connections

Good to know before installation

MarketAir states that the box is not rated as a firestop, and its spec sheet calls for an insulated drain pipe for the connection. The box position is planned from the indoor unit’s mounting plate.

Installed by AirGreen across Greater Montréal

Our refrigeration technicians install the RoughinBox at the rough-in stage, then the indoor unit, in Montréal, Laval, Longueuil, on the South Shore and on the North Shore. RBQ licence 5645-9605-01. For availability or a quote, call us at 514 316-2973 or email sales@airgreen.ca with the quantity you need.
01 · What it is for

Connections hidden in the wall, still reachable

The RoughinBox sits recessed in the wall behind the wall-mount indoor unit: lines, cable and drain arrive there cleanly.

  • Rough-in for wall-mount heat pumps in new construction
  • Major renovations where the lines run inside interior walls
  • Indoor units on an interior wall, away from an outside wall
  • Connecting the drain to a plumbing drain inside the wall
Built-in drainThe box floor slopes to a 3/4 in male NPT outlet that can discharge horizontally or vertically.
ReversibleThe box installs for line exits on the left or the right.
Access keptThe hinged faceplate and removable backplate give access to the connections after installation.
02 · Specifications

Specifications

From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.

BrandMarketAir
Model no.RBX3-MD-NC
Overall dimensions14-1/2 × 8 × 3-1/2 in (W × H × D)
Faceplate opening13 × 3-3/4 in
Line ports, top2, 2-1/2 × 3-3/4 in
Line port, bottom1, 4 × 3 in
Side ports2, optional
Wiring inlets1 × 1/2 in, 1 × 3/4 in
Drain outlet3/4 in male NPT, horizontal or vertical
MaterialPolyethylene, one-piece moulded
Studs16 in centres, wood or metal
Fire ratedNo
AirGreen codeAG-DR-004
03 · Before installing

What to know before installing

  • The box fits between studs at 16 in centres, wood or metal (integral adaptors).
  • The manufacturer states the box is not fire rated.
  • For the drain connection, the manufacturer’s specification calls for insulated drain hose.
  • A white plastic cover plate is available from the manufacturer as an option.
  • Check the box position against your indoor unit’s mounting plate.
In the package
  • Stud mounting adaptors
  • Two faceplate retainer clips
  • Extra indoor unit bracket support
  • Rubber drain adaptor (direct connection)
  • Instruction sheet
04 · Documents

Manufacturer documents

PDFSpec sheetMarketAirPDFInstallation manualMarketAir
05 · Goes with

You may also need

Tuyau de drain de condensat 5/8 po – rouleau de 100 pi5/8 in Condensate Drain Hose – 100 ft RollPompe à condensat pour thermopompe muraleCondensate Pump for Wall-Mounted Heat PumpEnsemble de lignes pré-isolées pour thermopompe murale – rouleau de 50 piPre-Insulated Line Set for Wall-Mounted Heat Pump – 50 ft RollCâble de communication 14/4 pour thermopompe14/4 Communication Cable for Heat PumpsIsolant élastomère Armaflex en tube – longueur de 6 piArmaflex Elastomeric Tube Insulation – 6 ft LengthPompe de relevage de condensat grande capacitéHigh-Capacity Condensate Pump
Job kitEverything for a wall-mount heat pump install
Line sets, brackets, cover, drain, disconnect and cable on one page.See the kitSame category
Condensate drainageSee all
06 · Questions

Frequently asked questions

Does the RoughinBox fit every wall-mount heat pump?

It takes the lines, cable and drain of a wall-mount indoor unit. Its position is planned from your model’s mounting plate: send us the model and we check before installing.

What is the box for in new construction?

It goes in before the drywall, with the lines and drain. The indoor unit is mounted later in front of the box, and the connections stay accessible.

Can a condensate pump go with it?

The manufacturer states the faceplate can serve as a base for an optional pump or reservoir. We choose the pump to suit your unit.

Can you install it?

Yes. Our technicians install the box at the rough-in stage, then the indoor unit, everywhere in Greater Montréal.

AirGreen · Montréal, Laval, Longueuil, South Shore, North Shore

A clean wall-mount installation, from wall to unit

Tell us the size and the quantity: we confirm availability and send you a quote. Or let our technicians install it for you.

Ask for a quote514 316-2973
RBQ 5645-9605-01Ventilation, refrigeration and electrical
Free estimateon site, for any installation
Quote in 24 hby phone or email
Bouchervilleshowroom

Specifications from the manufacturer’s documentation, checked on October 7, 2026.