A commercial fridge or freezer that is struggling to hold temperature is often blamed on the compressor, the thermostat or the age of the unit, when the real cause is far simpler: the unit cannot breathe. Every compressor needs to pull in cool air and push out the heat it removes from inside the cabinet, and when that airflow is blocked, the whole system works harder for a worse result.

Airflow problems build up quietly, a few centimetres of lost clearance here, a build-up of grease on a coil there, until a unit that used to run reliably starts short cycling, icing up or tripping on high temperature during a busy service. This guide covers the practical causes of poor airflow around commercial refrigeration and the fixes that make the biggest difference in a Melbourne kitchen.

Why Airflow Matters More Than Most Buyers Realise

A refrigeration unit works by moving heat from inside the cabinet to the air outside it. The compressor and condenser need a steady supply of cooler ambient air to dump that heat into, and the evaporator fan inside the cabinet needs clear space to circulate cold air evenly across every shelf. When either side of that system is restricted, the compressor runs longer and harder to reach the same set temperature, which shows up as a higher power bill, a shorter compressor life, and in the worst cases, food sitting above a safe temperature without anyone noticing until it is too late.

The good news is that most airflow problems are entirely preventable, and fixing them is usually cheaper than the alternative, which is an early compressor replacement or a call-out during a busy trading period. Four areas account for the large majority of airflow issues we see across Melbourne kitchens: compressor clearance, condenser cleanliness, internal loading, and ambient heat around the unit.

Compressor and Condenser Clearance

Every refrigeration unit has a minimum clearance specified by its manufacturer, usually a set number of centimetres behind the unit and above it, sometimes on the sides too depending on the design. This space is not a suggestion. It is the gap the condenser needs to pull in cool air and expel warm air without recirculating its own exhaust straight back into the intake, which is exactly what happens when a unit is pushed hard against a wall or boxed in by shelving to save floor space.

A kitchen under pressure to fit more equipment into a tight footprint is the most common place we see clearance compromised, often without anyone realising the cost. A unit running without its specified clearance can use noticeably more power for the same cooling result, and the compressor wears out faster carrying that extra load day after day. If your kitchen has grown equipment over the years without the layout being reviewed, it is worth checking every unit’s clearance against its manual, not just the newest arrivals.

This is also worth checking whenever a kitchen is rearranged, not just at the original fit-out. A new piece of equipment, a seasonal storage shelf, or even a stack of empty crates left beside a fridge during a busy week can all eat into clearance that was perfectly adequate when the unit was first installed. A quick walk-through of the kitchen with clearance specifically in mind, done every few months, catches this kind of drift before it becomes a habit.

Keeping Condenser Coils Clean

Why coils clog faster in a commercial kitchen

A condenser coil works like a radiator, with fine fins designed to shed heat into passing air. In a commercial kitchen, that air often carries cooking grease, flour dust or general airborne debris, and over weeks and months this builds up on the coil’s fins the same way grease builds up on a rangehood filter. A clogged coil cannot shed heat properly no matter how good the fan behind it is, so the compressor runs longer to compensate.

A cleaning routine that actually gets followed

Build coil cleaning into a routine staff actually follow, rather than a task that only happens when something has already gone wrong. A soft brush or a vacuum with a brush attachment, run gently along the fins every two to three months in a typical kitchen, catches most of the build-up before it affects performance. A kitchen running hot, greasy equipment nearby, such as a deep fryer or a flat grill, should check more often, since that environment clogs coils faster than a cooler prep area. Never use a pressure washer or anything abrasive on the fins, since bent fins block airflow just as effectively as grease does.

Forty Years of Hospitality Expertise, Since 1984

Since 1984 we have supplied the hospitality industry with professional advice, reliable equipment and excellent customer service. We have a wealth of experience in all types of projects ranging from international hotels to large and small pubs through to suburban restaurants and takeaway outlets. All our staff are equipped with the knowledge, expertise and creativity to add value to your project.

Forty years means we have been called out to more than a few units that looked faulty on paper but were simply starved of airflow, a compressor boxed in by a new storage shelf, a coil thick with kitchen grease, or a walk-in loaded so tightly the fan could not circulate air past the door. Fixing the airflow, not replacing the unit, solved the problem every time. You can read more about how we got here on our about page.

Loading Fridges and Freezers Without Blocking Airflow

Even a fridge with perfect external clearance and spotless coils can run poorly if it is loaded in a way that blocks internal airflow. Most reach-in and walk-in units cool using an evaporator fan that pushes air across every shelf in a specific pattern, and stacking product flush against the back wall or piling trays to the ceiling of a shelf interrupts that pattern. The result is usually an uneven cabinet, cold near the fan and uncomfortably warm in the corners furthest from it, which is a food safety risk as much as an efficiency one.

As a general guide, leave a visible gap at the back of each shelf so air can return to the fan, and avoid loading a shelf so full that nothing can move past it. Gastronorm pans and crates are usually sized to leave this gap automatically if used correctly, so an overloaded cabinet is often a sign that storage capacity, not just loading habits, needs a second look. If this is happening often, our guide on sizing a commercial fridge for your kitchen covers how to work out whether you genuinely need more capacity rather than better habits.

Train new staff on this specifically rather than assuming it is obvious, since a kitchen with regular staff turnover often sees loading habits slip gradually as new team members load shelves the way it is quickest, not necessarily the way that preserves airflow. A short explanation during onboarding, backed up by a simple diagram on the inside of the fridge door showing where product should and should not sit, keeps the habit consistent even as the team changes over time.

Ambient Heat and Kitchen Layout

A refrigeration unit does not operate in isolation from the rest of the kitchen. A fridge positioned beside a deep fryer, a char grill or any other heat-generating equipment is working against a hotter surrounding air temperature all day, which makes its job measurably harder regardless of how clean its coils are or how well it is loaded. Where possible, position refrigeration away from the hottest parts of the kitchen, or at minimum, make sure there is enough ventilation between the two that the fridge is not simply pulling in warm air from the cookline to try to cool itself.

Plant rooms and back-of-house areas housing larger condensing units need their own ventilation plan, since a poorly ventilated plant room can trap heat from several units at once, raising the ambient temperature they are all trying to work against. WorkSafe Victoria publishes general guidance on ventilation in commercial workplaces that is a useful starting point when planning or reviewing a plant room, alongside the specific advice your equipment supplier can give for your particular setup.

Door Seals, Refrigerant and When to Call a Technician

A worn or damaged door seal lets warm, humid air into a cabinet every time it fails to seal properly, and the resulting moisture often freezes onto the evaporator coil, which then restricts airflow inside the unit in a different way to a dirty condenser outside it. Run a simple visual check on seals regularly, and replace a seal showing cracks, tears or gaps rather than waiting for ice build-up to become obvious, since by that point the unit has likely been working harder than it should for some time.

Low refrigerant levels can also reduce a system’s ability to move heat efficiently, which compounds any airflow problem already present. Refrigerant work should only be carried out by a licensed technician, both because of the skill involved and because of Australia’s environmental regulations around refrigerant handling. The Australian Government’s ozone protection program sets out why refrigerant containment matters, and a reputable technician will handle it correctly as a matter of course. Book an annual service at minimum for any unit carrying real daily load, and more often for a heavily used walk-in or a unit in a hot plant room.

The Running Cost Case for Fixing Airflow

Every one of the fixes above costs little or nothing beyond staff time and the occasional service call, yet the running cost difference between a unit with good airflow and one without can be significant over a year of operation. Checking the energy rating of your equipment gives you a baseline for how efficiently a model should run under normal conditions, and a unit using noticeably more power than that baseline is a strong signal that an airflow issue, rather than a fault with the unit itself, is the real cause.

If you are weighing up whether an older unit is worth repairing or replacing, resolving airflow issues first is worth doing before that decision, since a unit that has been starved of airflow for a long time can look like it needs replacing when in fact it simply needs a clean, a seal replacement and some breathing room. Our guide to choosing the right commercial refrigeration covers what to look for if a genuine replacement does turn out to be the better option.

When Airflow Fixes Are Not Enough

Occasionally a unit has simply reached the end of its working life, and no amount of cleaning, clearance or seal replacement will bring its efficiency back to where it needs to be. This is more common in older equipment that has run for years with marginal airflow, since the cumulative strain on the compressor eventually causes genuine wear rather than a fixable blockage. If a technician confirms this is the case, replacing the unit is the better investment than continuing to patch an ageing compressor that will likely fail at the worst possible time.

When replacement is the right call, refurbished stock is worth considering for a secondary unit or a kitchen on a tighter budget, while new equipment suits a station that will carry heavy daily load for years to come. Compare our refurbished stock against new commercial refrigeration, and take the opportunity to review the layout around the new unit so the airflow problems that may have contributed to the old one’s early retirement do not simply repeat themselves. Our guide to setting up a commercial kitchen in Melbourne is a useful reference if you are reviewing more than just the one unit’s position.

Browse our full range of commercial refrigeration, our second-hand commercial kitchen equipment, or the wider range of commercial kitchen supplies we stock across Melbourne. When you would like a technician to take a look at an underperforming unit, get in touch with our team. It is free, there is no obligation, and there is no pressure.

Frequently Asked Questions (FAQs)