A panel air conditioner is a sealed cooling unit mounted on or inside an electrical enclosure. It keeps switchgear, PLCs and variable-speed drives within their rated temperature while the enclosure stays closed to dust and moisture. Unlike a filter fan, it can cool the interior below ambient temperature — which is the only workable option once the surrounding air is above roughly 40 °C.
Selection is a heat-balance calculation, not a catalogue pick. This page explains when a panel cooler is required, how capacity is calculated, what changes in 50 °C-plus ambient conditions, and which product ranges we supply from Istanbul.
Why Enclosure Temperature Decides Equipment Life
Electronic components degrade faster as they get hotter. The working rule in industry is that every 10 K above rated operating temperature roughly halves service life. A drive rated to 40 °C sitting in a 55 °C enclosure is not "running hot" — it is consuming its design life several times faster than intended.
The failures this produces are rarely dramatic. Capacitors dry out, contactors weld, drives derate and trip on hot afternoons, and the plant records them as random faults. The pattern only becomes visible when someone notices that the trips cluster in July and August, or in the enclosure standing next to the furnace.
Heat inside an enclosure comes from two directions: internal losses from the equipment itself — drives are typically 2–3% of rated power as heat, transformers and power supplies more — and external gain from ambient air and solar radiation on outdoor cabinets. Cooling must handle both.
Filter Fan, Heat Exchanger or Air Conditioner?
The deciding factor is the relationship between required internal temperature and ambient temperature. A filter fan or air-to-air heat exchanger can only bring the enclosure close to ambient; it can never go below it. Once ambient approaches or exceeds the equipment rating, a refrigerant-based panel air conditioner is the only option.
| Solution | Achievable internal temperature | Enclosure protection | Typical use |
|---|---|---|---|
| Filter fan and exhaust | Ambient + 5…10 K | Reduced — filtered air enters | Clean indoor areas, low ambient, low heat load |
| Air-to-air heat exchanger | Ambient + 5…15 K | Maintained — sealed circuits | Dusty or humid areas with moderate ambient |
| Air-to-water heat exchanger | Below ambient (water dependent) | Maintained | Plants with existing chilled or process water |
| Panel air conditioner | Below ambient — set point typically 35 °C | Maintained | High ambient, high heat load, outdoor cabinets |
Fitting filter fans in a plant where summer ambient reaches 45 °C. The fans work perfectly and the enclosure still sits at 50 °C, because a fan cannot deliver air colder than the air it draws in. The equipment fails anyway, and the fans are blamed for a fault that was designed in.
How Cooling Capacity Is Calculated
Required cooling output is the internal heat load minus what the enclosure surface can dissipate naturally: Qc = Pv − k · A · ΔT, where Pv is total component heat loss in watts, A is the effective enclosure surface area, k the heat transfer coefficient of the material, and ΔT the difference between desired internal and maximum ambient temperature. The method follows IEC 60890.
Two details decide whether the calculation is realistic. First, ΔT is often negative in hot climates: if you want 35 °C inside and ambient reaches 50 °C, the enclosure surface is gaining heat rather than losing it, and that gain adds to the load instead of subtracting from it. Second, effective surface area depends on how the enclosure is installed — a cabinet in a row with both sides blocked dissipates far less than a free-standing one.
To size a unit we need: total component heat loss, enclosure dimensions and mounting arrangement, material and colour, maximum ambient temperature at the installation point, and the required internal temperature. If component losses are unknown we can estimate from the drive and transformer ratings.
What Changes Above 45 °C Ambient
Standard panel air conditioners are rated to around +45 °C ambient. Above that, capacity falls sharply and units can trip on high condensing pressure. For Gulf, Iraqi and North African installations you need a high-temperature model rated to +55 °C — not a larger standard unit.
- Condenser fouling accelerates. Dust and sand build on the condenser coil within weeks. Specify accessible filters and plan cleaning intervals in months, not years.
- Condensate must be managed. In humid coastal sites a unit can produce litres per day. Specify condensate evaporation or a routed drain — not a bottle someone remembers to empty.
- Solar gain on outdoor cabinets is significant. A sun canopy often reduces required capacity more cheaply than the next unit size up.
- Derating is not optional. Catalogue capacity is quoted at reference conditions, typically 35 °C ambient / 35 °C internal. At 50 °C ambient the same unit delivers materially less.
Product Ranges We Supply
We supply and install Rittal (Blue e+ and standard ranges), Cosmotec / STULZ including 55 °C-capable models, and MKS Clima panel air conditioners, together with filter fans and air-to-air and air-to-water heat exchangers where those are the correct answer.
Spare parts — filters, fans, controllers, condensate pumps — are held in stock in Istanbul and ship by road or short sea freight to the Balkans and by air freight to the Gulf. For plants standardising on one platform across many cabinets we can quote a rolling spares package alongside the equipment.
Send us the enclosure schedule
Dimensions, component heat losses, mounting arrangement and the maximum ambient at each location. We return a unit selection per cabinet with derated capacity at your actual site conditions.
Technical consultation by phone or WhatsApp is free of charge · +90 216 344 48 19
Frequently Asked Questions
When do I need a panel air conditioner instead of a filter fan?
A filter fan can only bring the enclosure close to ambient temperature — never below it. Once your maximum ambient approaches the equipment rating, typically around 40 °C, a fan cannot solve the problem no matter how large it is. At that point a refrigerant-based panel air conditioner is the only option that cools below ambient.
How is the required cooling capacity calculated?
Required output equals total internal heat loss minus what the enclosure surface dissipates naturally: Qc = Pv − k · A · ΔT, following IEC 60890. In hot climates ΔT is often negative, meaning the enclosure gains heat from ambient and that gain adds to the load rather than reducing it.
Do panel air conditioners work at 50 °C ambient?
Standard units are rated to around +45 °C and lose capacity sharply above that. For 50 °C-plus environments you need a high-temperature model rated to +55 °C — a larger standard unit is not a substitute, because the limitation is condensing pressure rather than capacity.
What maintenance does a panel air conditioner need?
Condenser filter cleaning or replacement is the main task, and in dusty or sandy environments the interval can be as short as a few weeks. Beyond that: condensate drain check, fan operation check and periodic verification that door seals still close properly.
Where does the condensate go?
Units either evaporate condensate back into the condenser air stream or route it to a drain. In humid coastal climates production can reach several litres per day, so a routed drain or an evaporation system should be specified at order stage rather than improvised on site.
Can one unit cool several enclosures?
Only if the enclosures are joined so that air circulates between them. Separate sealed cabinets each need their own cooling. Where many cabinets stand in a row, an air-to-water solution fed from a central chiller is often more economical than one air conditioner per cabinet.
Does adding a panel cooler reduce the enclosure IP rating?
No, when the unit is correctly installed. Panel air conditioners use separate internal and external air circuits, so the enclosure stays sealed and IP54 or IP55 protection is maintained. This is the main advantage over filter fans, which necessarily admit outside air.
Do you supply outside Türkiye?
Yes. We supply Rittal, Cosmotec/STULZ and MKS Clima enclosure cooling across the Balkans, the Levant, North Africa and the Gulf from Istanbul, with spare parts held in stock. Selection studies and commissioning guidance are provided remotely; site attendance can be arranged for larger projects.