Articles

رادیران - تفاوت سوپرهیت اواپراتور و سوپرهیت ورودی کمپرسور Radiran -
02Nov

Evaporator Superheat vs. Compressor Inlet Superheat

Evaporator superheat and compressor inlet superheat are measured at different locations and serve different purposes. Evaporator superheat helps assess refrigerant feeding and evaporation within the evaporator. Compressor inlet superheat helps evaluate the condition of the refrigerant entering the compressor. Understanding this distinction is essential when adjusting expansion valves, diagnosing liquid floodback, and assessing refrigeration system performance.

What Is Superheat?

Superheat is the difference between the actual temperature of refrigerant vapor and its saturation temperature at the pressure prevailing at the same...

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رادیران - وکیوم سیستم تبرید چیست؟ هدف، تجهیزات و روش ارزیابی صحیح Radiran - What Is Refrigeration System Evacuation? Purpose, Equipment, and Proper Verification
31Oct

What Is Refrigeration System Evacuation? Purpose, Equipment, and Proper Verification

Refrigeration system evacuation is the process of reducing the pressure inside a refrigerant circuit using a vacuum pump to remove air, non-condensable gases, and moisture. It is normally performed before charging refrigerant during initial installation or after repairs that have exposed the circuit to the atmosphere. Evacuation quality cannot be assessed solely by how long the pump runs. Final system pressure, pressure behavior after isolating the pump, equipment temperature, and the extent of contamination all influence the result.

Why Must...

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رادیران - فین شکاف‌دار؛ تیغ دولبه در هوای آلوده
26Oct

Slit Fins: A Double-Edged Blade in Dirty Air

Slit and louvered fins are designed for one specific purpose: to break the air boundary layer, create controlled turbulence, and increase the heat-transfer coefficient. Under clean laboratory conditions, this geometry can raise the capacity of a fin-and-tube coil by 10 to 25% compared with a plain flat fin, which is why it looks so attractive in catalogs. But in units exposed to contaminated air, that same advantage turns into a weakness. The problem begins when the slits become particle traps. Industrial...

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Radiran - Why the fin spacing in a cold-room fin-and-tube evaporator should be greater than in an air-conditioning evaporator
24Oct

Why the fin spacing in a cold-room fin-and-tube evaporator should be greater than in an air-conditioning evaporator?

In fin-and-tube evaporators, the spacing between fins is one of the most important design parameters and must be selected according to the application. In cold storage rooms, the fin spacing is usually made greater than in air-conditioning evaporators, because the operating conditions are very different. In air conditioning, the coil temperature is generally higher and the surface is less likely to develop heavy frost. However, in cold storage systems, the coil temperature is lower, and the moisture in the air...

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رادیران - محل صحیح نصب بالب حسگر شیر انبساط ترموستاتیکی Radiran - Correct Placement of the Thermostatic Expansion Valve Sensing Bulb
20Oct

Correct Placement of the Thermostatic Expansion Valve Sensing Bulb

The location of the expansion valve sensing bulb directly affects superheat control, refrigerant feeding to the evaporator, and refrigeration system stability. Even when the valve is correctly selected, improper bulb installation can cause it to sense an unrepresentative temperature and regulate refrigerant flow incorrectly. This guide applies to thermostatic expansion valves. Sensor placement for electronic expansion valves must follow the instructions for the specific system.

What Does the Sensing Bulb Do?

The bulb senses the surface temperature of the suction line at its...

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برگشت مایع به کمپرسور؛ دلایل، نشانه‌ها و روش‌های پیشگیری Liquid Floodback to the Compressor: Causes, Signs, and Prevention Methods
10Oct

Liquid Floodback to the Compressor: Causes, Signs, and Prevention Methods

<p> Liquid floodback to the compressor occurs when, during system operation, some of the refrigerant enters the compressor through the suction line without fully evaporating. This phenomenon, known as “floodback,” can dilute the oil, reduce lubrication quality, and, in severe conditions, cause mechanical damage to the compressor. Replacing a damaged compressor without identifying the cause of liquid floodback does not resolve the problem. To prevent repeated failure, the evaporator’s operation, refrigerant feed control, load conditions, and system protection devices must be examined.

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سیستم فریونی یا آمونیاکی؛ کدام برای سردخانه مناسب‌تر است Halocarbon or Ammonia Refrigeration: Which Is Better for Cold Storage?
04Oct

Halocarbon or Ammonia Refrigeration: Which Is Better for Cold Storage?

Choosing between a halocarbon refrigeration system and an ammonia system is an important decision when designing a cold storage facility. Both can provide reliable cooling and freezing, but the right choice depends on the required capacity, operating temperatures, energy consumption, safety requirements, and long-term costs. There is no universal capacity threshold that makes one refrigerant the best option for every project. The refrigerant and system design should be evaluated together, based on the facility’s actual operating conditions.

What Is the...

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خم‌کاری درست لوله‌های مسی در کویل فین‌تیوب
29Sep

Proper Bending of Copper Tubes in Fintube Coils

Proper bending of copper tubes in finned-tube coils is one of the most important stages in manufacturing heat exchangers and heating or cooling systems. When this process is done correctly, the device works better, pressure drop is reduced, and the coil’s service life increases. In contrast, improper bending can cause tube flattening, cracking, reduced fluid flow, and even leakage. Copper tube is one of the best choices for fintube coils because it is flexible, has high thermal conductivity, and resists corrosion...

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شیر سرویس کمپرسور چیست و چگونه کار می‌کند
27Sep

Compressor Service Valves: How the Three Positions Work

<p> A compressor service valve provides access to a refrigeration system for pressure measurement and certain service procedures. Service valves are commonly installed at the compressor’s suction or discharge connection. Moving the valve stem changes how the compressor, refrigerant line, and gauge port communicate. This article describes a common three-way compressor service valve. Valve designs differ, so check the instructions for the installed model before operating it.

Main parts of a service valve

A typical three-way service valve has three connections and an adjustable...

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کمپرسور صنعتی با لوله دهش داغ؛ بیش گرم شدن کمپرسور در سیستم تبرید
23Sep

Compressor Overheating in refrigeration system: Causes and Troubleshooting

<p> Compressor overheating is a warning sign that a refrigeration system may be operating outside its intended conditions. Prolonged exposure to excessive heat can reduce oil viscosity and weaken lubrication. Depending on the compressor design and how long the problem continues, it may lead to component wear, oil breakdown, valve damage, or motor failure. The right response is to identify why the compressor is running hot. Cooling its exterior or changing a control setting without diagnosing the system may leave the underlying...

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