Self-Contained vs Remote Walk-In Refrigeration
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By Renato J. Alonso, Founder and President, Qube Cold Storage Solutions · Updated October 23, 2026
A self-contained system packages all of the walk-in's refrigeration in one piece that mounts on top of or through the wall of the box. It is the simplest and least expensive to install, but it puts the heat and noise of the condensing unit right next to the walk-in. A remote split system puts the condensing unit outside or on the roof and connects it to an evaporator inside the walk-in with refrigerant lines. It costs more to install and needs a refrigeration technician, but it handles hot kitchens and larger rooms better and keeps the kitchen cooler and quieter.
Side by side
| Self-contained (top-mount or side-mount) | Remote split | |
|---|---|---|
| What it is | Condensing unit and evaporator built as one unit, mounted on the walk-in | Condensing unit outside or on the roof; evaporator inside; connected by refrigerant lines |
| Installation | Set it, wire it, start it. Usually no refrigeration piping on site. | Mount both pieces, run and braze the line set, pull a vacuum, charge and start. Needs a certified refrigeration technician. |
| Installed cost | Lower | Higher, mainly for line sets, roof work and technician time |
| Heat | Rejects heat into the room around the walk-in | Rejects heat outside |
| Noise | Compressor noise in the kitchen or back room | Compressor noise outside |
| Ceiling space | Needs clear space above the walk-in for airflow and service | Only the evaporator is inside; little space needed above |
| Best for | Small and mid-size boxes in rooms with good ventilation, tenant spaces where roof work is difficult, projects that may move | Hot kitchens, larger walk-ins, freezers, rooms with low ceilings, and anywhere noise or heat matters |
| Service | One piece, easy to replace as a unit | Components serviced separately; outdoor unit is easier to reach without entering the kitchen |
How to decide
- Where would the heat go? A self-contained unit dumps its heat into the room it sits in. In a small, hot kitchen with no ventilation, that heat raises the room temperature, which makes the walk-in work harder, which makes more heat. If the room is already hot, go remote.
- Is there a place for a condensing unit outside? A roof, a pad, or an outside wall within a reasonable line-set distance. If the building or the landlord will not allow roof penetrations, self-contained may be the only practical choice.
- How much ceiling clearance is there? A top-mount unit needs space above the walk-in for air and service. In a room with a low ceiling, a side-mount or a remote system may be the only fit. See what to measure before you choose a size.
- How big is the box, and is it a freezer? As boxes grow, remote systems become more common, and freezers in hot kitchens benefit the most from moving the heat outside.
- Who will install it? A remote system needs a refrigeration technician on site. A self-contained system can often be set and wired by an electrician, with a technician for startup.
Outdoor and hot-climate installs
Condensing units are rated to work up to certain outdoor temperatures. In hot climates like South Florida, Arizona and Texas, the refrigeration has to be selected for the real summer temperature where the condensing unit will sit, which on a dark roof can be well above the forecast high. In cold climates, outdoor condensing units need low-ambient controls and heaters so they keep running in winter. Either way, the selection should be made for your ZIP code, not from a generic chart.
Electrical
Most small walk-in condensing units run on 208-230V single-phase, with the evaporator on 115V. Three-phase power is common in larger buildings and should be matched to the site. Confirm your building's voltage and phase before the refrigeration is ordered; a unit wired for the wrong phase cannot simply be adjusted on site.
Want the right system selected for your room? Send the walk-in size, temperature, where the condensing unit can go, and your ZIP code. Qube matches the refrigeration to the real load and puts the model numbers on the quote.
Questions people ask
What is the difference between self-contained and remote walk-in refrigeration?
A self-contained system is a single unit mounted on the walk-in. A remote split system puts the condensing unit outside or on the roof and connects it to an evaporator inside with refrigerant lines.
Is a self-contained walk-in cooler cheaper?
Usually cheaper to install, because there is no refrigerant piping on site. Equipment prices for small boxes are often similar.
Can I put a top-mount walk-in in a hot kitchen?
You can, but it adds heat to a room that is already hot, and the system will work harder. In hot, poorly ventilated kitchens, a remote system is usually the better choice.
Does a remote walk-in system need a refrigeration technician?
Yes. The refrigerant lines have to be run, brazed, evacuated and charged by a certified refrigeration technician.
What voltage does a walk-in cooler need?
Most small condensing units use 208-230V single-phase, with the evaporator, lights and door heaters on 115V. Larger systems often use three-phase. Match the equipment to the building before ordering.
Sources
- Qube Cold Storage Solutions published standards: condensing units 208-230V single-phase and evaporators 115V, three-phase to match the site.